Mining activities have caused significant land degradation globally,emphasizing the need for effective restoration.Microbial inoculants offer a promising solution for sustainable remediation by enhancing soil nutrient...Mining activities have caused significant land degradation globally,emphasizing the need for effective restoration.Microbial inoculants offer a promising solution for sustainable remediation by enhancing soil nutrients,enzyme activities,and microbial communities to support plant growth.However,the mechanisms by which inoculants influence soil microbes and their relationship with plant growth require further investigation.Metagenomic sequencing was employed for this study,based on a one-year greenhouse experiment,to elucidate the effects of Bacillus thuringiensis NL-11 on the microbial functions of abandoned mine soils.Our findings revealed that the application of microbial inoculants significantly enhanced the soil total carbon(TC),total sulfur(TS),organic carbon(SOC),available phosphorus(AP),ammonium(NH4+),urease,arylsulfatase,phosphatase,β-1,4-glucosidase(BG),β-1,4-N-acetylglucosaminidase(NAG).Moreover,this led to substantial improvements in plant height,as well as aboveground and belowground biomass.Microbial inoculants impacted functional gene structures without altering diversity.The normalized abundance of genes related to the degradation of carbon and nitrogen,methane metabolism,and nitrogen fixation were observed to increase,as well as the functional genes related to phosphorus cycling.Significant correlations were found between nutrient cycling gene abundance and plant biomass.Partial Least Squares Path Model analysis showed that microbial inoculants not only directly influenced plant biomass but also indirectly affected the plant biomass through C cycle modifications.This study highlights the role of microbial inoculants in promoting plant growth and soil restoration by improving soil properties and enhancing normalized abundance of nutrient cycling gene,making them essential for the recovery of abandoned mine sites.展开更多
[Objectives]This study was conducted to investigate the mechanism of continuous cropping obstacles in Polygonatum odoratum.[Methods]Three treatments were established:continuous cropping(two consecutive crops),first-cr...[Objectives]This study was conducted to investigate the mechanism of continuous cropping obstacles in Polygonatum odoratum.[Methods]Three treatments were established:continuous cropping(two consecutive crops),first-crop control(with Phaseolus vulgaris as the preceding crop),and blank control.The effects of continuous cropping on the functional diversity of soil microorganisms,soil enzyme activities,and soil nutrient coordination in the rhizosphere soil of P.odoratum during different growth stages were investigated.[Results](1)Continuous cropping increased the carbon source metabolic capacity,Shannon diversity index,and richness of rhizosphere soil microorganisms by 3.2%-14.7%,0.9%-3.5%,and 1.3%-12.5%,respectively,but the differences were not significant.(2)Principal component analysis indicated that during the middle stage of rhizome expansion,continuous cropping significantly altered the characteristics of microbial carbon metabolism,and the microbial communities utilizing carbohydrates,amino acids,polymers,carboxylic acids and amines as carbon sources exhibited vigorous metabolism.(3)Continuous cropping significantly reduced the activities of urease,polyphenol oxidase,and acid phosphatase in rhizosphere soil,with decreases of 24.4%-39.5%,3.2%-14.8%,and 7.9%-18.2%,respectively.The activities of catalase and invertase sometimes exceeded and sometimes fell below those of the first crop,showing no consistent pattern.(4)Under continuous cropping conditions,nutrient imbalance occurred in the rhizosphere soil,characterized by nitrogen deficiency and phosphorus surplus.(5)Grey correlation analysis indicated that available phosphorus content,alkali-hydrolyzable nitrogen content and polyphenol oxidase activity in rhizosphere soil were the main factors influencing microbial functional diversity.[Conclusions]This study provides a theoretical basis for understanding the formation mechanism of continuous cropping obstacles in P.odoratum.展开更多
Background,aim,and scope Soil microbes are important drivers of nutrient transformation and energy f low.Reclaiming forest land for agricultural use may have profound effects on soil properties and microbial communiti...Background,aim,and scope Soil microbes are important drivers of nutrient transformation and energy f low.Reclaiming forest land for agricultural use may have profound effects on soil properties and microbial communities.However,the response of soil microbial communities to soil reclamation in the dryland agroecosystem is less understood.Therefore,it is necessary to investigate the changes of soil microbial communities driven by land use conversion to promote nutrient cycling in reclaimed farmland.Materials and methods Based on the metagenomic technique,we evaluated the microbial composition and function of the newly created farmland(NF)after reclamation with two types of traditional farmland(slope farmland(SF),checkdam farmland(CF))on the Loess Plateau,and explored the response of nutrient cycling function to dominant genera and soil properties.Results The results showed that Proteobacteria,Actinobacteria,and Acidobacteria were prevalent in the three types of farmlands.Compared with SF and CF,NF increased the relative abundance of Actinobacteria and Nocardioides,as well as genes related to amino acid metabolism and carbohydrate metabolism.The relative abundance of functional genes related to carbon and nitrogen cycling in the NF was higher than that in the traditional farmland(SF and CF).The relative abundance of nutrient cycling functional genes was positively correlated with dominant genera in the three types of farmlands.Except for pH,soil physicochemical factors were negatively correlated with genes related to amino acid metabolism and carbon cycle.Discussion Previous studies have shown that the nutrient conditions of the soil may intensify the competition between the eutrophic and oligotrophic microbial populations.After long-term cultivation and fertilization,the soil properties of traditional farmland were significantly different from those of NF,leading to the differentiation of dominant microbial groups.Microbes usually have functional redundancy to cope with changing environments.Soil microbes in traditional farmland may contain more genes related to replication and repair,cell growth and death,and environmental adaptation in response to disturbances caused by agricultural practices.On the contrary,the NF was less disturbed by agricultural activities,and the soil properties were more similar to forest land,so the carbon and nitrogen cycle function genes were more abundant.The nutrient cycling function was affected by the abundance of microbial dominant groups and soil properties,which may be related to the availability of soil nutrients and agricultural disturbance in different farmlands.Aspects of soil microbial-driven nutrient cycling in agriculture could be regulated in sustainable method.Conclusions The change from forest land to farmland kept more carbon and nitrogen cycling function in the newly created farmland,while long-term agricultural activities have drastically changed the functional structure of traditional farmland,resulting in the nutrient cycling function more concentrated to meet the needs of crop growth.Recommendations and perspectives Hence,it is necessary to apply sustainable agricultural method to regulate microbial-driven nutrient cycling.The insights are meaningful for sustainable agricultural development and land management in arid areas.展开更多
Degradation of chlorpyrifos at different concentrations in soil and its impact on soil microbial functional diversity were investigated under laboratory condition. The degradation half-live of chlorpyrifos at levels o...Degradation of chlorpyrifos at different concentrations in soil and its impact on soil microbial functional diversity were investigated under laboratory condition. The degradation half-live of chlorpyrifos at levels of 4, 8, and 12 mg/kg in soil were calculated to be 14.3, 16.7, and 18.0 d, respectively. The Biolog study showed that the average well color development （AWCD） in soils was significantly （P 〈 0.05） inhibited by chlorpyrifos within the first two weeks and thereafter recovered to a similar level as the control. A similar variation in the diversity indices （Simpson index lID and McIntosh index U） was observed, but no significant difference among the values of the Shannon-Wiener index H＇ was found in chlorpyrifos-treated soils. With an increasing chlorpyrifos concentration, the half-life of chlorpyrifos was significantly （P ≤ 0.05） extended and its inhibitory effect on soil microorganisms was aggravated. It is concluded that chlorpyrifos residues in soil had a temporary or short-term inhibitory effect on soil microbial functional diversity.展开更多
An experiment with seven N, P, K-fertilizer treatments, i.e., control (no fertilizer), NP, NK, PK, NPK, NP2K, and NPK2 where P2 and K2 indicate double amounts of P and K fertilizers respectively, was conducted to exam...An experiment with seven N, P, K-fertilizer treatments, i.e., control (no fertilizer), NP, NK, PK, NPK, NP2K, and NPK2 where P2 and K2 indicate double amounts of P and K fertilizers respectively, was conducted to examine the effect of long-term continuous application of chemical fertilizers on microbial biomass and functional diversity of a black soil (Udoll in the USDA Soil Taxonomy) in Northeast China. The soil microbial biomass C ranged between 94 and 145 mg kg-1, with the NK treatment showing a lower biomass; the functional diversity of soil microbial community ranged from 4.13 to 4.25, with an increasing tendency from control to double-fertilizer treatments, and to triple-fertilizer treatments. The soil microbial biomass, and the microbial functional diversity and evenness did not show any significant differences among the different fertilizer treatments including control, suggesting that the long-term application of chemical fertilization would not result in significant changes in the microbial characteristics of the black soil.展开更多
Copper （Cu） mine tailings, because of their high content of heavy metals, are usually hostile to plant colonization. A pot experiment was conducted to determine the tolerance of four forage grasses to heavy metals i...Copper （Cu） mine tailings, because of their high content of heavy metals, are usually hostile to plant colonization. A pot experiment was conducted to determine the tolerance of four forage grasses to heavy metals in Cu mine tailings and to examine the variation in the microbial functional diversity of soils from the tailing sites in southern China. All the four grass species survived on Cu mine tailings and Cu mine tailing-soil mixture. However, on pure mine tailings, the growth was minimal, whereas the growth was maximum for the control without mine tailings. The tolerance of grasses to heavy metals followed the sequence： Paspalum notatum 〉 Festuea arundinaeea 〉 Lolium perenne 〉 Cynodon daetylon. The planting of forage grasses enhanced the soil microbial biomass. The Biolog data indicated that the soil microbial metabolic profile values （average well color development, community richness, and Shannon index） of the four forage grasses also followed the sequence： P. notatum 〉 F. arundinaeea 〉 L. perenne 〉 C. daetylon. Thus, P. notatum, under the experimental conditions of this study, may be considered as the preferred plant species for revegetation of Cu mine tailing areas.展开更多
Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small water...Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small watershed of subtropical region of China was selected for this study. Land uses covered paddy fields, vegetable farming, fruit trees, upland crops, bamboo stands, and forestry. Soil biological and biochemical properties included soil organic C and nutrient contents, mineralization of soil organic C, and soil microbial biomass and community functional diversity. Soil organic C and total N contents, microbial biomass C and N, and respiration intensity under different land uses were changed in the following order： paddy fields （and vegetable farming） 〉 bamboo stands 〉 fruit trccs （and upland）. The top surface （0-15 cm） paddy fields （and vegetable farming） were 76.4 and 80.8% higher in soil organic C and total N contents than fruit trees （and upland） soils, respectively. Subsurface paddy soils （15-30 cm） were 59.8 and 67.3% higher in organic C and total N than upland soils, respectively. Soil microbial C, N and respiration intensity in paddy soils （0-15 cm） were 6.36, 3.63 and 3.20 times those in fruit tree （and upland） soils respectively. Soil microbial metabolic quotient was in the order： fruit trees （and upland） 〉 forestry 〉 paddy fields. Metabolic quotient in paddy soils was only 47.7% of that in fruit tree （and upland） soils. Rates of soil organic C mineralization during incubation changed in the order： paddy fields 〉 bamboo stands 〉 fruit trees （and upland） and soil bacteria population： paddy fields 〉 fruit trees （and upland） 〉 forestry. No significant difference was found for fungi and actinomycetes populations. BIOLOG analysis indicated a changing order of paddy fields 〉 fruit trees （and upland） 〉 forestry in values of the average well cell development （AWCD） and functional diversity indexes of microbial community. Results also showed that the conversion from paddy fields to vegetable farming for 5 years resulted in a dramatic increase in soil available phosphorus content while insignificant changes in soil organic C and total N content due to a large inputs of phosphate fertilizers. This conversion caused 53, 41.5, and 41.3% decreases in soil microbial biomass C, N, and respiration intensity, respectively, while 23.6% increase in metabolic quotient and a decrease in soil organic C mineralization rate. Moreover, soil bacteria and actinomycetes populations were increased slightly, while fungi population increased dramatically. Functional diversity indexes of soil microbial community decreased significantly. It was concluded that land uses in the subtropical region of China strongly affected soil biological and biochemical properties. Soil organic C and nutrient contents, mineralization of organic C and functional diversity of microbial community in paddy fields were higher than those in upland and forestry. Overuse of chemical fertilizers in paddy fields with high fertility might degrade soil biological properties and biochemical function, resulting in deterioration of soil biological quality.展开更多
This study was conducted to characterize the diversity and function of microbial communities in marine sediments of the Pearl River Mouth Basin(PRMB)in the South China Sea.The results showed that the bacterial and arc...This study was conducted to characterize the diversity and function of microbial communities in marine sediments of the Pearl River Mouth Basin(PRMB)in the South China Sea.The results showed that the bacterial and archaeal communities varied greatly with depth.Proteobacteria in bacterial communities and Nitrososphaeria and Woesearchaeota in archaeal communities were dominant in the shallow sediments(1-40 cm),while Chloroflexi in bacterial communities and Bathyarchaeia in archaeal communities were dominant in the deep sediments(50-200 cm).Regarding ecological functions based on the metatranscriptomic data,genes involved in various pathways of nitrogen metabolism and sulfur metabolism were observed in the tested sediment samples.Metagenomic analysis revealed that Proteobacteria contribute the most to nearly all genes involved in nitrogen and sulfur metabolism.Moreover,Thaumarchaeota contribute the most to certain genes involved in nitrification,denitrification and assimilatory sulfate reduction pathways.The most abundant bacterial genus,Candidatus Scalindua,is crucial for nitrification,dissimilatory nitrate reduction,denitrification and assimilatory sulfate reduction pathways.展开更多
The eff ect of seasons on the soil microbiome in a Larix gmelinii forest of Mohe,China,where winter temperatures are generally below−40°C,was evaluated with metagenomics analysis.Taxonomic profi ling using sequen...The eff ect of seasons on the soil microbiome in a Larix gmelinii forest of Mohe,China,where winter temperatures are generally below−40°C,was evaluated with metagenomics analysis.Taxonomic profi ling using sequencing information revealed that Proteobacteria,Actinobacteria,Acidobacteria and Verrucomicrobia were the dominant phyla in spring,summer,and fall,as were Bradyrhizobium,Chthoniobacter,Streptomyces,Acid Candidatus Koribacter at the genus level.Some species that were abundant in spring and fall greatly diminished in abundance in summer.Clusters of orthologous groups(COG)of proteins,carbohydrate-active enzymes(CAZy),Kyoto Encyclopedia of Genes and Genomes(KEGG)and NCBI databases were used to elucidate the function of diverse proteins and metabolites of the microbial community of L.gmelinii forest.COG analysis showed that fewer genes were detected in spring than in fall and summer,indicating that many soil microbes in the L.gmelinii forest were not tolerant to cold.Based on KEGG analysis,some pathways in the soil microbes were activated in spring and autumn and deactivated in summer.CAZy analysis revealed that most CAZy were more active in summer than in spring or autumn and were severely inhibited in the spring.Many functional pathways,proteins,and CAZy involved in the community changes were concerned with cold or heat resistance.Therefore,the soil in the L.gmelinii forest can be a valuable resource for further research on heat and cold tolerance of soil microbes.展开更多
Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental ...Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental characteristics especially organic carbon availability after 15-yr different organic and inorganic fertilizer inputs on soil bacterial community structure and functional metabolic diversity of soil microbial communities were evaluated in a 15-yr fertilizer experiment in Changping County, Beijing, China. The experiment was a wheat-maize rotation system which was established in 1991 including four different fertilizer treatments. These treatments included： a non-amended control（CK）, a commonly used application rate of inorganic fertilizer treatment（NPK）; a commonly used application rate of inorganic fertilizer with swine manure incorporated treatment（NPKM）, and a commonly used application rate of inorganic fertilizer with maize straw incorporated treatment（NPKS）. Denaturing gradient gel electrophoresis（DGGE） of the 16 S r RNA gene was used to determine the bacterial community structure and single carbon source utilization profiles were determined to characterize the microbial community functional metabolic diversity of different fertilizer treatments using Biolog Eco plates. The results indicated that long-term fertilized treatments significantly increased soil bacterial community structure compared to CK. The use of inorganic fertilizer with organic amendments incorporated for long term（NPKM, NPKS） significantly promoted soil bacterial structure than the application of inorganic fertilizer only（NPK）, and NPKM treatment was the most important driver for increases in the soil microbial community richness（S） and structural diversity（H）. Overall utilization of carbon sources by soil microbial communities（average well color development, AWCD） and microbial substrate utilization diversity and evenness indices（H＇ and E） indicated that long-term inorganic fertilizer with organic amendments incorporated（NPKM, NPKS） could significantly stimulate soil microbial metabolic activity and functional diversity relative to CK, while no differences of them were found between NPKS and NPK treatments. Principal component analysis（PCA） based on carbon source utilization profiles also showed significant separation of soil microbial community under long-term fertilization regimes and NPKM treatment was significantly separated from the other three treatments primarily according to the higher microbial utilization of carbohydrates, carboxylic acids, polymers, phenolic compounds, and amino acid, while higher utilization of amines/amides differed soil microbial community in NPKS treatment from those in the other three treatments. Redundancy analysis（RDA） indicated that soil organic carbon（SOC） availability, especially soil microbial biomass carbon（Cmic） and Cmic/SOC ratio are the key factors of soil environmental characteristics contributing to the increase of both soil microbial community structure and functional metabolic diversity in the long-term fertilization trial. Our results showed that long-term inorganic fertilizer and swine manure application could significantly improve soil bacterial community structure and soil microbial metabolic activity through the increases in SOC availability, which could provide insights into the sustainable management of China＇s soil resource.展开更多
In order to promote the transformation and high-quality development of strawberry industry and speed up the application of functional microbial products in strawberry,the application technology of functional microbial...In order to promote the transformation and high-quality development of strawberry industry and speed up the application of functional microbial products in strawberry,the application technology of functional microbial products in strawberry planting is studied and summarized.It mainly includes:the periods and methods of continuous cropping strawberry soil reduction and disinfection at high temperature,before and after strawberry planting,before plastic film mulching and whole process of plant spraying.Through multi-point test and demonstration,the purpose of advancing the season of strawberries,improving the quality,increasing production and increasing efficiency is achieved,and there is no risk of agricultural residue pollution,which meets the needs of people's consumption upgrading.Therefore,the application of functional microbial products in green ecological planting is very necessary,and it is worth further speeding up the demonstration and promotion.展开更多
Microplastics and heavy metal contamination poses major threats to soil function and food security;however,their synergistic effects remain largely unclear.This study investigated the effects of single or combined add...Microplastics and heavy metal contamination poses major threats to soil function and food security;however,their synergistic effects remain largely unclear.This study investigated the effects of single or combined addition of polyethylene(PE)microplastic(1%w/w)and cadmium(Cd;1.5 and 5 mg kg^(-1))on functional microbial communities in the wheat rhizosphere soil.We observed that the biomass of wheat increased by 142.44%under high doses of Cd addition.The bacterial alpha diversity in wheat bulk soil reduced by 37.34%–37.83%with the combined addition of microplastic and Cd.The addition of microplastic reduced the relative abundance of Proteus involved in nitrogen fixation by 19.93%,while the relative abundance of Proteus and Actinobacteria involved in nitrogen cycling increased with the increase of Cd concentration,increasing by 27.96%–37.37%and 51.14%–55.04%,respectively.FAPROTAX analysis revealed that increasing Cd concentration promoted the abundance of functional bacterial communities involved in nitrification/denitrification and nitrate/nitrite respiration in rhizosphere soil.A FunGuild analysis showed that the synergy of PE-microplastics and Cd increased the abundance of saprophytic fungi,suggesting an enhanced degradation function.Our findings provide new knowledge on the effects of microplastics and heavy metals on soil microorganisms and functional microbial communities in agricultural soil.展开更多
Granular sludges can resist the toxicity inhibition of medium-chain fatty acids(MCFAs)and enhance the chain elongation(CE)process.However,the granulation process is time-consuming and requires a suitable facilitating ...Granular sludges can resist the toxicity inhibition of medium-chain fatty acids(MCFAs)and enhance the chain elongation(CE)process.However,the granulation process is time-consuming and requires a suitable facilitating granulation mean.This study proposed two continuous fed Expanded Granular Sludge Bed bioreactors,one with electric field(EF)and one without,to demonstrate the promotion of sludge granulation by EF and the enhancement of MCFAs production efficiency by the anaerobic granular sludge(An GS).Through more than 50 days of operation,the EF was demonstrated to be able to promote the granulation,and the formed An GS enhanced MCFAs yield by 36%.Besides,mechanism analysis indicated that the EF promoted microbial aggregation and extracellular polymeric substances(EPS)synthesis,which enabled An GS to form more easily.Besides,An GS formed with EF improved extracellular electron transfer capacity and microbial function activity,which also contributed to the production of more MCFAs.Overall,this study provides a method to facilitate An GS granulation and revealed the underlying mechanisms,and offers important support for the diverse applications of An GS in other bioresources recovery bioprocesses.展开更多
A field experiment with rice-rice rotation was conducted since 2002 in southeast China for investigating the response of soil microbial properties to intensive nitrogen fertilizer application. The tested soil was a su...A field experiment with rice-rice rotation was conducted since 2002 in southeast China for investigating the response of soil microbial properties to intensive nitrogen fertilizer application. The tested soil was a subtropical paddy soil derived from Quaternary red clay. Differences between treatments existed in different application rates of urea when the experiment was designed. Urea was applied in five rates, i.e., 0, 0.5, 1, 1.5, and 2 U, equivalent to 0, 0.5, 1, 1.5, and 2 times the local average amount of urea application （900 kg urea ha-~ yr-~, equivalent to 414 kg N ha-1 yr-~）. In 2007, soil total nitrogen, available nitrogen, and soil organic carbon contents were increased by 10.2-27.9, 8.0-16.0, and 10.2-30.6%, respectively, in treatments with urea application rates of 0.5 to 2 U compared to control （0 U）. Microbial biomass carbon and nitrogen were also increased by 3.1-30.8 and 1.3-13.9%, respectively, in treatments with urea application. Basal respiration in treatments with urea input were 9.4-29.1% higher than that in control. However, changes of bacterial functional diversity had different trends. Urea fertilization enhanced bacterial functional diversity until treatment of 1 U, but re-decreased it from treatment of 1.5 U. Principal components analysis indicated that there were intimate relationships among soil organic matter, nitrogen nutrient, microbial biomass, and respiration. Nevertheless, microbial diversity was related to soil moisture contents after urea application. We conclude here that the application of N fertilizer improved soil microbial biomass and respiratory activity. But, microbial diversity was reduced when excessive urea was applied in the tested paddy soil.展开更多
Phyllostachys praecox C. D. Chu et C. S. Chao, a favored bamboo shoot species, has been widely planted in recent years. Four stands with different historical management practices were selected for this study to unders...Phyllostachys praecox C. D. Chu et C. S. Chao, a favored bamboo shoot species, has been widely planted in recent years. Four stands with different historical management practices were selected for this study to understand the evolution of soil microbial ecology by determining the effects of a new mulching and heavy fertilization practice on soil quality using microbiological parameters. Compared with the traditional practice (index 1), microbial biomass carbon (MBC) and soil microbial respiration carbon (MRC) with the new management practice significantly decreased (P ＜ 0.01 and P ＜ 0.05,respectively) with 1-2 years of mulching (index 2) and then for continued mulching significantly increased (P ＜ 0.05). The ratios of MBC/TOC (total organic carbon) and MRC/TOC also significantly diminished (P ＜ 0.05) with mulching. The average well color development (AWCD) and Shannon index decreased with mulching time, and the significant decrease(P ＜ 0.05) in Shannon index occurred from index 2 to index 3. The results from a principal components analysis (PCA)showed that the scores of the first principal component for indexes 1 and 2 were significantly larger (P ＜ 0.05) than soils mulched 3-4 years or 5-6 years. Also, the second principal component scores for index 1 were larger than those for index 2, suggesting that the ability of soil microorganisms to utilize soil carbon was decreasing with longer use of the new management practice and causing a deterioration of soil biological properties.展开更多
The enzymes and the characteristics of the community of the petroleum-degrading bacteria play a crucial role in the crude oil biodegradation. The prediction of kinetics of the key groups of hydrocarbons in crude oil w...The enzymes and the characteristics of the community of the petroleum-degrading bacteria play a crucial role in the crude oil biodegradation. The prediction of kinetics of the key groups of hydrocarbons in crude oil was important to evaluate the bioremediation speed and constant. Most of the n-alkanes(C9-C29) were degraded in 25 days, and the average degradation rates of C_(18)~C_(27) higher than 100 μg g^(-1) d^(-1).The hopanes, such as H_(30), had a biodegradation rate more than 10 μg g^(-1) d^(-1). The related enzymes activities changed along with the crude oil biodegradation, especially dehydrogenase. The 16 S rRNA gene amplicon sequencing revealed that Proteobacteria, Firmcutes, Bacteroidetes, Actinobacteria, Acidobacteria were the main petroleum hydrocarbon degraders during the crude oil biodegradation, and the top two highest relative abundance of the genera were Alcaligenes and Acinetobacter. Acinetobacter presented positive correlation to biodegradation of n-alkanes and PAHs. Based on COG analysis, the largest group involved in the general function was amino acid transport and metabolism. The functional categories of bacterial communities were mainly focused on the carbohydrate and amino acid metabolism, xenobiotics biodegradation and metabolism, membrane transport, and so on. Overall, these findings highlight the potential guideline for more adequate monitoring of microbial degradation of crude oil.展开更多
Soil organic matter(SOM)in boreal forests is an important carbon sink.The aim of this study was to assess and to detect factors controlling the temperature sensitivity of SOM decomposition.Soils were collected from Sc...Soil organic matter(SOM)in boreal forests is an important carbon sink.The aim of this study was to assess and to detect factors controlling the temperature sensitivity of SOM decomposition.Soils were collected from Scots pine,Norway spruce,silver birch,and mixed forests(O horizon)in northern Finland,and their basal respiration rates at five different temperatures(from 4 to 28℃)were measured.The Q10 values,showing the respiration rate changes with a 10℃ increase,were calculated using a Gaussian function and were based on temperature-dependent changes.Several soil physicochemical parameters were measured,and the functional diversity of the soil microbial communities was assessed using the MicroResp?method.The temperature sensitivity of SOM decomposition differed under the studied forest stands.Pine forests had the highest temperature sensitivity for SOM decomposition at the low temperature range(0–12℃).Within this temperature range,the Q10 values were positively correlated with the microbial functional diversity index(H’mic)and the soil C-to-P ratio.This suggested that the metabolic abilities of the soil microbial communities and the soil nutrient content were important controls of temperature sensitivity in taiga soils.展开更多
Monitoring soil microbial communities can lead to better understanding of the transformation processes of organic carbon in soil. The present study investigated the changes of soil microbial communities during straw d...Monitoring soil microbial communities can lead to better understanding of the transformation processes of organic carbon in soil. The present study investigated the changes of soil microbial communities during straw decomposition in three fields, i.e., cropland, peach orchard and vineyard. Straw decomposition was monitored for 360 d using a mesh-bag method. Soil microbial metabolic activity and functional diversity were measured using the Biolog-Eco system. In all three fields, dried straws with a smaller size decomposed faster than their fresh counterparts that had a larger size. Dried corn straw decomposed slower than dried soybean straw in the early and middle stages, while the reverse trend was found in the late stage. The cropland showed the highest increase in microbial metabolic activity during the straw decomposition, whereas the peach orchard showed the lowest. There was no significant change in the species dominance or evenness of soil microbial communities during the straw decomposition. However, the species richness fluctuated significantly, with the peach orchard showing the highest richness and the cropland the lowest. With different carbon sources, the peach orchard utilised carbon the most, followed by the cropland and the vineyard. In all three fields, carbon was utilized in following decreasing order： saccharides〉amino acids〉polymers〉polyamines〉carboxylic acids〉aromatic compounds. In terms of carbon-source utilization, soil microbial communities in the peach orchard were less stable than those in the cropland. The metabolic activity and species dominance of soil microbial communities were negatively correlated with the straw residual percentage. Refractory components were primarily accumulated in the late stages, thus slowing down the straw decomposition. The results showed that dried and crushed corn straw was better for application in long-term fields. The diversity of soil microbial communities was more stable in cropland than in orchards during the straw decomposition.展开更多
Alpine wetlands are hotspots of carbon(C)storage and methane emission,and they could be key contributors to global warming.In recent years,rapid warming has lowered the water table in alpine wetlands on the Tibetan Pl...Alpine wetlands are hotspots of carbon(C)storage and methane emission,and they could be key contributors to global warming.In recent years,rapid warming has lowered the water table in alpine wetlands on the Tibetan Plateau,concurrent with intensified nitrogen(N)deposition via anthropogenic activities.We carried out a field experiment to investigate the ecological impacts of these two factors on soil bacterial and functional communities,which are essential drivers of greenhouse gas emissions.Nitrogen amendment alone decreased the phylogenetic alpha-diversity of bacterial communities which could be offset by lowered water table.In contrast,microbial functional alpha-diversity,revealed by a high-throughput microarray,remained unchanged.Both bacterial and functional beta-diversity responded to lowered water table,but only bacterial community responded to N amendment.The alpha-Proteobacteria,beta-Proteobacteria,and Bacteroidetes were the major responsive bacterial lineages,and C degradation,methanogenesis,alkaline shock,and phosphorus oxidation were the major responsive functional processes.Partitioning analysis revealed that N amendment changed bacterial community structure mainly via species loss processes but did not affect bacterial functional communities,with soil pH and ammonium as the key factors influencing changes in bacterial community structure.Conversely,lowered water table altered bacterial and functional communities through species substitution processes linked to soil pH and soil moisture.According to our results,the response mechanisms of microbial communities to lowered water table and N amendment are fundamentally different in alpine wetlands.展开更多
A field experiment involving cry1Ab transgenic rice(GM) and its parental non-cry1Ab rice(M) has been on-going since 2014. The diversity of the bacterial communities and the abundance of the microbial functional genes ...A field experiment involving cry1Ab transgenic rice(GM) and its parental non-cry1Ab rice(M) has been on-going since 2014. The diversity of the bacterial communities and the abundance of the microbial functional genes which drive the conversion of nitrogen in paddy soil were analyzed during the growth period of rice in the fifth year of the experiment, using 16 S rRNAbased Illumina Mi Seq and real-time PCR on the amoA, nirS and nirK genes. The results showed no differences in the alpha diversity indexes of the bacterial communities, including Chao1, Shannon and Simpson, between the fields cultivated with line GM and cultivar M at any of the growth stages of rice. However, the bacterial communities in the paddy soil with line GM were separated from those of paddy soil with cultivar M at each of the growth stages of rice, based on the unweighted Uni Frac NMDS or PCoA. In addition, the analyses of ADONIS and ANOSIM, based on the unweighted Uni Frac distance, indicated that the above separations between line GM and cultivar M were statistically significant(P<0.05) during the growth season of rice. The increases in the relative abundances of Acidobacteria or Bacteroidetes, in the paddy soils with line GM or cultivar M, respectively, led to the differences in the bacterial communities between them. At the same time, functional gene prediction based on Illumina Mi Seq data suggested that the abundance of many functional genes increased in the paddy soil with line GM at the maturity stage of rice, such as genes related to the metabolism of starch, amino acids and nitrogen. Otherwise, the copies of bacterial amo A gene, archaeal amo A gene and denitrifying bacterial nir K gene significantly increased(P<0.05 or 0.01) in the paddy soil with line GM. In summary, the release of cry1Ab transgenic rice had effects on either the composition of bacterial communities or the abundance of microbial functional genes in the paddy soil.展开更多
基金supported by the Jiangsu Science and Technology Plan Project(No.BE2022420)the Innovation and Promotion of Forestry Science and Technology Program of Jiangsu Province(No.LYKJ[2021]30)+2 种基金the Scientific Research Project of Baishanzu National Park(No.2021ZDLY01)the Ningxia key research and development plan(No.2021BEG02010)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Mining activities have caused significant land degradation globally,emphasizing the need for effective restoration.Microbial inoculants offer a promising solution for sustainable remediation by enhancing soil nutrients,enzyme activities,and microbial communities to support plant growth.However,the mechanisms by which inoculants influence soil microbes and their relationship with plant growth require further investigation.Metagenomic sequencing was employed for this study,based on a one-year greenhouse experiment,to elucidate the effects of Bacillus thuringiensis NL-11 on the microbial functions of abandoned mine soils.Our findings revealed that the application of microbial inoculants significantly enhanced the soil total carbon(TC),total sulfur(TS),organic carbon(SOC),available phosphorus(AP),ammonium(NH4+),urease,arylsulfatase,phosphatase,β-1,4-glucosidase(BG),β-1,4-N-acetylglucosaminidase(NAG).Moreover,this led to substantial improvements in plant height,as well as aboveground and belowground biomass.Microbial inoculants impacted functional gene structures without altering diversity.The normalized abundance of genes related to the degradation of carbon and nitrogen,methane metabolism,and nitrogen fixation were observed to increase,as well as the functional genes related to phosphorus cycling.Significant correlations were found between nutrient cycling gene abundance and plant biomass.Partial Least Squares Path Model analysis showed that microbial inoculants not only directly influenced plant biomass but also indirectly affected the plant biomass through C cycle modifications.This study highlights the role of microbial inoculants in promoting plant growth and soil restoration by improving soil properties and enhancing normalized abundance of nutrient cycling gene,making them essential for the recovery of abandoned mine sites.
文摘[Objectives]This study was conducted to investigate the mechanism of continuous cropping obstacles in Polygonatum odoratum.[Methods]Three treatments were established:continuous cropping(two consecutive crops),first-crop control(with Phaseolus vulgaris as the preceding crop),and blank control.The effects of continuous cropping on the functional diversity of soil microorganisms,soil enzyme activities,and soil nutrient coordination in the rhizosphere soil of P.odoratum during different growth stages were investigated.[Results](1)Continuous cropping increased the carbon source metabolic capacity,Shannon diversity index,and richness of rhizosphere soil microorganisms by 3.2%-14.7%,0.9%-3.5%,and 1.3%-12.5%,respectively,but the differences were not significant.(2)Principal component analysis indicated that during the middle stage of rhizome expansion,continuous cropping significantly altered the characteristics of microbial carbon metabolism,and the microbial communities utilizing carbohydrates,amino acids,polymers,carboxylic acids and amines as carbon sources exhibited vigorous metabolism.(3)Continuous cropping significantly reduced the activities of urease,polyphenol oxidase,and acid phosphatase in rhizosphere soil,with decreases of 24.4%-39.5%,3.2%-14.8%,and 7.9%-18.2%,respectively.The activities of catalase and invertase sometimes exceeded and sometimes fell below those of the first crop,showing no consistent pattern.(4)Under continuous cropping conditions,nutrient imbalance occurred in the rhizosphere soil,characterized by nitrogen deficiency and phosphorus surplus.(5)Grey correlation analysis indicated that available phosphorus content,alkali-hydrolyzable nitrogen content and polyphenol oxidase activity in rhizosphere soil were the main factors influencing microbial functional diversity.[Conclusions]This study provides a theoretical basis for understanding the formation mechanism of continuous cropping obstacles in P.odoratum.
文摘Background,aim,and scope Soil microbes are important drivers of nutrient transformation and energy f low.Reclaiming forest land for agricultural use may have profound effects on soil properties and microbial communities.However,the response of soil microbial communities to soil reclamation in the dryland agroecosystem is less understood.Therefore,it is necessary to investigate the changes of soil microbial communities driven by land use conversion to promote nutrient cycling in reclaimed farmland.Materials and methods Based on the metagenomic technique,we evaluated the microbial composition and function of the newly created farmland(NF)after reclamation with two types of traditional farmland(slope farmland(SF),checkdam farmland(CF))on the Loess Plateau,and explored the response of nutrient cycling function to dominant genera and soil properties.Results The results showed that Proteobacteria,Actinobacteria,and Acidobacteria were prevalent in the three types of farmlands.Compared with SF and CF,NF increased the relative abundance of Actinobacteria and Nocardioides,as well as genes related to amino acid metabolism and carbohydrate metabolism.The relative abundance of functional genes related to carbon and nitrogen cycling in the NF was higher than that in the traditional farmland(SF and CF).The relative abundance of nutrient cycling functional genes was positively correlated with dominant genera in the three types of farmlands.Except for pH,soil physicochemical factors were negatively correlated with genes related to amino acid metabolism and carbon cycle.Discussion Previous studies have shown that the nutrient conditions of the soil may intensify the competition between the eutrophic and oligotrophic microbial populations.After long-term cultivation and fertilization,the soil properties of traditional farmland were significantly different from those of NF,leading to the differentiation of dominant microbial groups.Microbes usually have functional redundancy to cope with changing environments.Soil microbes in traditional farmland may contain more genes related to replication and repair,cell growth and death,and environmental adaptation in response to disturbances caused by agricultural practices.On the contrary,the NF was less disturbed by agricultural activities,and the soil properties were more similar to forest land,so the carbon and nitrogen cycle function genes were more abundant.The nutrient cycling function was affected by the abundance of microbial dominant groups and soil properties,which may be related to the availability of soil nutrients and agricultural disturbance in different farmlands.Aspects of soil microbial-driven nutrient cycling in agriculture could be regulated in sustainable method.Conclusions The change from forest land to farmland kept more carbon and nitrogen cycling function in the newly created farmland,while long-term agricultural activities have drastically changed the functional structure of traditional farmland,resulting in the nutrient cycling function more concentrated to meet the needs of crop growth.Recommendations and perspectives Hence,it is necessary to apply sustainable agricultural method to regulate microbial-driven nutrient cycling.The insights are meaningful for sustainable agricultural development and land management in arid areas.
基金supported by the National Hi-Tech Research and Development Program (863) of China (No.2006AA06Z386, 2007AA06Z306)the China Postdoctor-al Science Foundation (No. 20070421174)+2 种基金the National Natural Science Foundation of China (No. 30771254)the Zhejiang Provincial Natural Science Foundation (No.Z306260)the National Key Technologies R&D Pro-gram of China (No. 2006BAI09B03)
文摘Degradation of chlorpyrifos at different concentrations in soil and its impact on soil microbial functional diversity were investigated under laboratory condition. The degradation half-live of chlorpyrifos at levels of 4, 8, and 12 mg/kg in soil were calculated to be 14.3, 16.7, and 18.0 d, respectively. The Biolog study showed that the average well color development （AWCD） in soils was significantly （P 〈 0.05） inhibited by chlorpyrifos within the first two weeks and thereafter recovered to a similar level as the control. A similar variation in the diversity indices （Simpson index lID and McIntosh index U） was observed, but no significant difference among the values of the Shannon-Wiener index H＇ was found in chlorpyrifos-treated soils. With an increasing chlorpyrifos concentration, the half-life of chlorpyrifos was significantly （P ≤ 0.05） extended and its inhibitory effect on soil microorganisms was aggravated. It is concluded that chlorpyrifos residues in soil had a temporary or short-term inhibitory effect on soil microbial functional diversity.
基金the National Natural Science Foundation of China (No.40321101)the Ministry of Science and Technology of China (No.2005CB121105) the Knowledge Innovation Program of the Chinese Academy of Sciences(Nos.KZCX1-SW-19 and KZCX2-YW-408).
文摘An experiment with seven N, P, K-fertilizer treatments, i.e., control (no fertilizer), NP, NK, PK, NPK, NP2K, and NPK2 where P2 and K2 indicate double amounts of P and K fertilizers respectively, was conducted to examine the effect of long-term continuous application of chemical fertilizers on microbial biomass and functional diversity of a black soil (Udoll in the USDA Soil Taxonomy) in Northeast China. The soil microbial biomass C ranged between 94 and 145 mg kg-1, with the NK treatment showing a lower biomass; the functional diversity of soil microbial community ranged from 4.13 to 4.25, with an increasing tendency from control to double-fertilizer treatments, and to triple-fertilizer treatments. The soil microbial biomass, and the microbial functional diversity and evenness did not show any significant differences among the different fertilizer treatments including control, suggesting that the long-term application of chemical fertilization would not result in significant changes in the microbial characteristics of the black soil.
基金the National Natural Sciences Foundation of China (Nos40171054 and 40125005)the National Key Basic Research Support Foundation of China (No2002CB410809/10)
文摘Copper （Cu） mine tailings, because of their high content of heavy metals, are usually hostile to plant colonization. A pot experiment was conducted to determine the tolerance of four forage grasses to heavy metals in Cu mine tailings and to examine the variation in the microbial functional diversity of soils from the tailing sites in southern China. All the four grass species survived on Cu mine tailings and Cu mine tailing-soil mixture. However, on pure mine tailings, the growth was minimal, whereas the growth was maximum for the control without mine tailings. The tolerance of grasses to heavy metals followed the sequence： Paspalum notatum 〉 Festuea arundinaeea 〉 Lolium perenne 〉 Cynodon daetylon. The planting of forage grasses enhanced the soil microbial biomass. The Biolog data indicated that the soil microbial metabolic profile values （average well color development, community richness, and Shannon index） of the four forage grasses also followed the sequence： P. notatum 〉 F. arundinaeea 〉 L. perenne 〉 C. daetylon. Thus, P. notatum, under the experimental conditions of this study, may be considered as the preferred plant species for revegetation of Cu mine tailing areas.
基金the National Natural Science Foundation of China （40471066） the Knowledge Innovation Program of the Chinese Academy of Sciences （KZCX3-SW-417）.
文摘Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small watershed of subtropical region of China was selected for this study. Land uses covered paddy fields, vegetable farming, fruit trees, upland crops, bamboo stands, and forestry. Soil biological and biochemical properties included soil organic C and nutrient contents, mineralization of soil organic C, and soil microbial biomass and community functional diversity. Soil organic C and total N contents, microbial biomass C and N, and respiration intensity under different land uses were changed in the following order： paddy fields （and vegetable farming） 〉 bamboo stands 〉 fruit trccs （and upland）. The top surface （0-15 cm） paddy fields （and vegetable farming） were 76.4 and 80.8% higher in soil organic C and total N contents than fruit trees （and upland） soils, respectively. Subsurface paddy soils （15-30 cm） were 59.8 and 67.3% higher in organic C and total N than upland soils, respectively. Soil microbial C, N and respiration intensity in paddy soils （0-15 cm） were 6.36, 3.63 and 3.20 times those in fruit tree （and upland） soils respectively. Soil microbial metabolic quotient was in the order： fruit trees （and upland） 〉 forestry 〉 paddy fields. Metabolic quotient in paddy soils was only 47.7% of that in fruit tree （and upland） soils. Rates of soil organic C mineralization during incubation changed in the order： paddy fields 〉 bamboo stands 〉 fruit trees （and upland） and soil bacteria population： paddy fields 〉 fruit trees （and upland） 〉 forestry. No significant difference was found for fungi and actinomycetes populations. BIOLOG analysis indicated a changing order of paddy fields 〉 fruit trees （and upland） 〉 forestry in values of the average well cell development （AWCD） and functional diversity indexes of microbial community. Results also showed that the conversion from paddy fields to vegetable farming for 5 years resulted in a dramatic increase in soil available phosphorus content while insignificant changes in soil organic C and total N content due to a large inputs of phosphate fertilizers. This conversion caused 53, 41.5, and 41.3% decreases in soil microbial biomass C, N, and respiration intensity, respectively, while 23.6% increase in metabolic quotient and a decrease in soil organic C mineralization rate. Moreover, soil bacteria and actinomycetes populations were increased slightly, while fungi population increased dramatically. Functional diversity indexes of soil microbial community decreased significantly. It was concluded that land uses in the subtropical region of China strongly affected soil biological and biochemical properties. Soil organic C and nutrient contents, mineralization of organic C and functional diversity of microbial community in paddy fields were higher than those in upland and forestry. Overuse of chemical fertilizers in paddy fields with high fertility might degrade soil biological properties and biochemical function, resulting in deterioration of soil biological quality.
基金the National Natural Science Foundation of China(Nos.41620104001 and 41806131)the Scientific and Technological Innovation Project of the Qingdao National Laboratory for Marine Science and Technology(No.2016 ASKJ02).
文摘This study was conducted to characterize the diversity and function of microbial communities in marine sediments of the Pearl River Mouth Basin(PRMB)in the South China Sea.The results showed that the bacterial and archaeal communities varied greatly with depth.Proteobacteria in bacterial communities and Nitrososphaeria and Woesearchaeota in archaeal communities were dominant in the shallow sediments(1-40 cm),while Chloroflexi in bacterial communities and Bathyarchaeia in archaeal communities were dominant in the deep sediments(50-200 cm).Regarding ecological functions based on the metatranscriptomic data,genes involved in various pathways of nitrogen metabolism and sulfur metabolism were observed in the tested sediment samples.Metagenomic analysis revealed that Proteobacteria contribute the most to nearly all genes involved in nitrogen and sulfur metabolism.Moreover,Thaumarchaeota contribute the most to certain genes involved in nitrification,denitrification and assimilatory sulfate reduction pathways.The most abundant bacterial genus,Candidatus Scalindua,is crucial for nitrification,dissimilatory nitrate reduction,denitrification and assimilatory sulfate reduction pathways.
基金the National Natural Science Foundation of China(No.31670494).
文摘The eff ect of seasons on the soil microbiome in a Larix gmelinii forest of Mohe,China,where winter temperatures are generally below−40°C,was evaluated with metagenomics analysis.Taxonomic profi ling using sequencing information revealed that Proteobacteria,Actinobacteria,Acidobacteria and Verrucomicrobia were the dominant phyla in spring,summer,and fall,as were Bradyrhizobium,Chthoniobacter,Streptomyces,Acid Candidatus Koribacter at the genus level.Some species that were abundant in spring and fall greatly diminished in abundance in summer.Clusters of orthologous groups(COG)of proteins,carbohydrate-active enzymes(CAZy),Kyoto Encyclopedia of Genes and Genomes(KEGG)and NCBI databases were used to elucidate the function of diverse proteins and metabolites of the microbial community of L.gmelinii forest.COG analysis showed that fewer genes were detected in spring than in fall and summer,indicating that many soil microbes in the L.gmelinii forest were not tolerant to cold.Based on KEGG analysis,some pathways in the soil microbes were activated in spring and autumn and deactivated in summer.CAZy analysis revealed that most CAZy were more active in summer than in spring or autumn and were severely inhibited in the spring.Many functional pathways,proteins,and CAZy involved in the community changes were concerned with cold or heat resistance.Therefore,the soil in the L.gmelinii forest can be a valuable resource for further research on heat and cold tolerance of soil microbes.
基金funded by the National Natural Science Foundation of China(NSFC31301843)the National Nonprofit Institute Research Grant of Chinese Academy of Agricultural Sciences(IARRP-202-5)
文摘Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental characteristics especially organic carbon availability after 15-yr different organic and inorganic fertilizer inputs on soil bacterial community structure and functional metabolic diversity of soil microbial communities were evaluated in a 15-yr fertilizer experiment in Changping County, Beijing, China. The experiment was a wheat-maize rotation system which was established in 1991 including four different fertilizer treatments. These treatments included： a non-amended control（CK）, a commonly used application rate of inorganic fertilizer treatment（NPK）; a commonly used application rate of inorganic fertilizer with swine manure incorporated treatment（NPKM）, and a commonly used application rate of inorganic fertilizer with maize straw incorporated treatment（NPKS）. Denaturing gradient gel electrophoresis（DGGE） of the 16 S r RNA gene was used to determine the bacterial community structure and single carbon source utilization profiles were determined to characterize the microbial community functional metabolic diversity of different fertilizer treatments using Biolog Eco plates. The results indicated that long-term fertilized treatments significantly increased soil bacterial community structure compared to CK. The use of inorganic fertilizer with organic amendments incorporated for long term（NPKM, NPKS） significantly promoted soil bacterial structure than the application of inorganic fertilizer only（NPK）, and NPKM treatment was the most important driver for increases in the soil microbial community richness（S） and structural diversity（H）. Overall utilization of carbon sources by soil microbial communities（average well color development, AWCD） and microbial substrate utilization diversity and evenness indices（H＇ and E） indicated that long-term inorganic fertilizer with organic amendments incorporated（NPKM, NPKS） could significantly stimulate soil microbial metabolic activity and functional diversity relative to CK, while no differences of them were found between NPKS and NPK treatments. Principal component analysis（PCA） based on carbon source utilization profiles also showed significant separation of soil microbial community under long-term fertilization regimes and NPKM treatment was significantly separated from the other three treatments primarily according to the higher microbial utilization of carbohydrates, carboxylic acids, polymers, phenolic compounds, and amino acid, while higher utilization of amines/amides differed soil microbial community in NPKS treatment from those in the other three treatments. Redundancy analysis（RDA） indicated that soil organic carbon（SOC） availability, especially soil microbial biomass carbon（Cmic） and Cmic/SOC ratio are the key factors of soil environmental characteristics contributing to the increase of both soil microbial community structure and functional metabolic diversity in the long-term fertilization trial. Our results showed that long-term inorganic fertilizer and swine manure application could significantly improve soil bacterial community structure and soil microbial metabolic activity through the increases in SOC availability, which could provide insights into the sustainable management of China＇s soil resource.
基金Supported by Zhenjiang Key R&D Program(NY2020017).
文摘In order to promote the transformation and high-quality development of strawberry industry and speed up the application of functional microbial products in strawberry,the application technology of functional microbial products in strawberry planting is studied and summarized.It mainly includes:the periods and methods of continuous cropping strawberry soil reduction and disinfection at high temperature,before and after strawberry planting,before plastic film mulching and whole process of plant spraying.Through multi-point test and demonstration,the purpose of advancing the season of strawberries,improving the quality,increasing production and increasing efficiency is achieved,and there is no risk of agricultural residue pollution,which meets the needs of people's consumption upgrading.Therefore,the application of functional microbial products in green ecological planting is very necessary,and it is worth further speeding up the demonstration and promotion.
基金supported by the Ningbo Science and Technology Bureau(Grant No.2022S103)the National Natural Science Foundation of China(Grant Nos.42107341,42307420)+1 种基金the UK Natural Environment Research Council and the Global Challenges Research Fund(Grant No.NE/V005871/1)the K.C.Wong Magna Fund at Ningbo University.
文摘Microplastics and heavy metal contamination poses major threats to soil function and food security;however,their synergistic effects remain largely unclear.This study investigated the effects of single or combined addition of polyethylene(PE)microplastic(1%w/w)and cadmium(Cd;1.5 and 5 mg kg^(-1))on functional microbial communities in the wheat rhizosphere soil.We observed that the biomass of wheat increased by 142.44%under high doses of Cd addition.The bacterial alpha diversity in wheat bulk soil reduced by 37.34%–37.83%with the combined addition of microplastic and Cd.The addition of microplastic reduced the relative abundance of Proteus involved in nitrogen fixation by 19.93%,while the relative abundance of Proteus and Actinobacteria involved in nitrogen cycling increased with the increase of Cd concentration,increasing by 27.96%–37.37%and 51.14%–55.04%,respectively.FAPROTAX analysis revealed that increasing Cd concentration promoted the abundance of functional bacterial communities involved in nitrification/denitrification and nitrate/nitrite respiration in rhizosphere soil.A FunGuild analysis showed that the synergy of PE-microplastics and Cd increased the abundance of saprophytic fungi,suggesting an enhanced degradation function.Our findings provide new knowledge on the effects of microplastics and heavy metals on soil microorganisms and functional microbial communities in agricultural soil.
基金supported by the Natural Science Foundation of Heilongjiang Province(No.LH2023E051)Open Project of State Key Laboratory of Urban Water Resource and Environment(No.HC202241)Young Scientist Studio of Harbin Institute of Technology。
文摘Granular sludges can resist the toxicity inhibition of medium-chain fatty acids(MCFAs)and enhance the chain elongation(CE)process.However,the granulation process is time-consuming and requires a suitable facilitating granulation mean.This study proposed two continuous fed Expanded Granular Sludge Bed bioreactors,one with electric field(EF)and one without,to demonstrate the promotion of sludge granulation by EF and the enhancement of MCFAs production efficiency by the anaerobic granular sludge(An GS).Through more than 50 days of operation,the EF was demonstrated to be able to promote the granulation,and the formed An GS enhanced MCFAs yield by 36%.Besides,mechanism analysis indicated that the EF promoted microbial aggregation and extracellular polymeric substances(EPS)synthesis,which enabled An GS to form more easily.Besides,An GS formed with EF improved extracellular electron transfer capacity and microbial function activity,which also contributed to the production of more MCFAs.Overall,this study provides a method to facilitate An GS granulation and revealed the underlying mechanisms,and offers important support for the diverse applications of An GS in other bioresources recovery bioprocesses.
基金supported by the National Basic Research Program of China (973 Program,2007CB109301)the National Key Technology R & D Program of China (2009BADC6B03)Asia-Europe Link Project (CN-Asia-Link-001,81468)
文摘A field experiment with rice-rice rotation was conducted since 2002 in southeast China for investigating the response of soil microbial properties to intensive nitrogen fertilizer application. The tested soil was a subtropical paddy soil derived from Quaternary red clay. Differences between treatments existed in different application rates of urea when the experiment was designed. Urea was applied in five rates, i.e., 0, 0.5, 1, 1.5, and 2 U, equivalent to 0, 0.5, 1, 1.5, and 2 times the local average amount of urea application （900 kg urea ha-~ yr-~, equivalent to 414 kg N ha-1 yr-~）. In 2007, soil total nitrogen, available nitrogen, and soil organic carbon contents were increased by 10.2-27.9, 8.0-16.0, and 10.2-30.6%, respectively, in treatments with urea application rates of 0.5 to 2 U compared to control （0 U）. Microbial biomass carbon and nitrogen were also increased by 3.1-30.8 and 1.3-13.9%, respectively, in treatments with urea application. Basal respiration in treatments with urea input were 9.4-29.1% higher than that in control. However, changes of bacterial functional diversity had different trends. Urea fertilization enhanced bacterial functional diversity until treatment of 1 U, but re-decreased it from treatment of 1.5 U. Principal components analysis indicated that there were intimate relationships among soil organic matter, nitrogen nutrient, microbial biomass, and respiration. Nevertheless, microbial diversity was related to soil moisture contents after urea application. We conclude here that the application of N fertilizer improved soil microbial biomass and respiratory activity. But, microbial diversity was reduced when excessive urea was applied in the tested paddy soil.
文摘Phyllostachys praecox C. D. Chu et C. S. Chao, a favored bamboo shoot species, has been widely planted in recent years. Four stands with different historical management practices were selected for this study to understand the evolution of soil microbial ecology by determining the effects of a new mulching and heavy fertilization practice on soil quality using microbiological parameters. Compared with the traditional practice (index 1), microbial biomass carbon (MBC) and soil microbial respiration carbon (MRC) with the new management practice significantly decreased (P ＜ 0.01 and P ＜ 0.05,respectively) with 1-2 years of mulching (index 2) and then for continued mulching significantly increased (P ＜ 0.05). The ratios of MBC/TOC (total organic carbon) and MRC/TOC also significantly diminished (P ＜ 0.05) with mulching. The average well color development (AWCD) and Shannon index decreased with mulching time, and the significant decrease(P ＜ 0.05) in Shannon index occurred from index 2 to index 3. The results from a principal components analysis (PCA)showed that the scores of the first principal component for indexes 1 and 2 were significantly larger (P ＜ 0.05) than soils mulched 3-4 years or 5-6 years. Also, the second principal component scores for index 1 were larger than those for index 2, suggesting that the ability of soil microorganisms to utilize soil carbon was decreasing with longer use of the new management practice and causing a deterioration of soil biological properties.
基金funded by the Shandong Provincial Natural Science Foundation [Grant number: ZR2018MD018]Yantai University Doctoral Start-up Foundation [Grant number: HX2018B32]Shandong Key Laboratory of Marine Ecological Restoration (Grant number: 201919)。
文摘The enzymes and the characteristics of the community of the petroleum-degrading bacteria play a crucial role in the crude oil biodegradation. The prediction of kinetics of the key groups of hydrocarbons in crude oil was important to evaluate the bioremediation speed and constant. Most of the n-alkanes(C9-C29) were degraded in 25 days, and the average degradation rates of C_(18)~C_(27) higher than 100 μg g^(-1) d^(-1).The hopanes, such as H_(30), had a biodegradation rate more than 10 μg g^(-1) d^(-1). The related enzymes activities changed along with the crude oil biodegradation, especially dehydrogenase. The 16 S rRNA gene amplicon sequencing revealed that Proteobacteria, Firmcutes, Bacteroidetes, Actinobacteria, Acidobacteria were the main petroleum hydrocarbon degraders during the crude oil biodegradation, and the top two highest relative abundance of the genera were Alcaligenes and Acinetobacter. Acinetobacter presented positive correlation to biodegradation of n-alkanes and PAHs. Based on COG analysis, the largest group involved in the general function was amino acid transport and metabolism. The functional categories of bacterial communities were mainly focused on the carbohydrate and amino acid metabolism, xenobiotics biodegradation and metabolism, membrane transport, and so on. Overall, these findings highlight the potential guideline for more adequate monitoring of microbial degradation of crude oil.
基金The research received funding from the European Union Seventh Framework Programme(FP7/2007-2013)under grant agreement No.262693(INTERACT)by Jagiel-lonian University,Poland(subsidy DS/WBiNoZ/INoS/758).
文摘Soil organic matter(SOM)in boreal forests is an important carbon sink.The aim of this study was to assess and to detect factors controlling the temperature sensitivity of SOM decomposition.Soils were collected from Scots pine,Norway spruce,silver birch,and mixed forests(O horizon)in northern Finland,and their basal respiration rates at five different temperatures(from 4 to 28℃)were measured.The Q10 values,showing the respiration rate changes with a 10℃ increase,were calculated using a Gaussian function and were based on temperature-dependent changes.Several soil physicochemical parameters were measured,and the functional diversity of the soil microbial communities was assessed using the MicroResp?method.The temperature sensitivity of SOM decomposition differed under the studied forest stands.Pine forests had the highest temperature sensitivity for SOM decomposition at the low temperature range(0–12℃).Within this temperature range,the Q10 values were positively correlated with the microbial functional diversity index(H’mic)and the soil C-to-P ratio.This suggested that the metabolic abilities of the soil microbial communities and the soil nutrient content were important controls of temperature sensitivity in taiga soils.
基金supported by the Soil Erosion and Dryland Farming on Loess Plateau of the State Key Laboratory of Chinese Academy of Sciences (K318009902-1310) the Shaanxi Province Innovative Engineering Project Coordinator (2011K01-48)
文摘Monitoring soil microbial communities can lead to better understanding of the transformation processes of organic carbon in soil. The present study investigated the changes of soil microbial communities during straw decomposition in three fields, i.e., cropland, peach orchard and vineyard. Straw decomposition was monitored for 360 d using a mesh-bag method. Soil microbial metabolic activity and functional diversity were measured using the Biolog-Eco system. In all three fields, dried straws with a smaller size decomposed faster than their fresh counterparts that had a larger size. Dried corn straw decomposed slower than dried soybean straw in the early and middle stages, while the reverse trend was found in the late stage. The cropland showed the highest increase in microbial metabolic activity during the straw decomposition, whereas the peach orchard showed the lowest. There was no significant change in the species dominance or evenness of soil microbial communities during the straw decomposition. However, the species richness fluctuated significantly, with the peach orchard showing the highest richness and the cropland the lowest. With different carbon sources, the peach orchard utilised carbon the most, followed by the cropland and the vineyard. In all three fields, carbon was utilized in following decreasing order： saccharides〉amino acids〉polymers〉polyamines〉carboxylic acids〉aromatic compounds. In terms of carbon-source utilization, soil microbial communities in the peach orchard were less stable than those in the cropland. The metabolic activity and species dominance of soil microbial communities were negatively correlated with the straw residual percentage. Refractory components were primarily accumulated in the late stages, thus slowing down the straw decomposition. The results showed that dried and crushed corn straw was better for application in long-term fields. The diversity of soil microbial communities was more stable in cropland than in orchards during the straw decomposition.
文摘Alpine wetlands are hotspots of carbon(C)storage and methane emission,and they could be key contributors to global warming.In recent years,rapid warming has lowered the water table in alpine wetlands on the Tibetan Plateau,concurrent with intensified nitrogen(N)deposition via anthropogenic activities.We carried out a field experiment to investigate the ecological impacts of these two factors on soil bacterial and functional communities,which are essential drivers of greenhouse gas emissions.Nitrogen amendment alone decreased the phylogenetic alpha-diversity of bacterial communities which could be offset by lowered water table.In contrast,microbial functional alpha-diversity,revealed by a high-throughput microarray,remained unchanged.Both bacterial and functional beta-diversity responded to lowered water table,but only bacterial community responded to N amendment.The alpha-Proteobacteria,beta-Proteobacteria,and Bacteroidetes were the major responsive bacterial lineages,and C degradation,methanogenesis,alkaline shock,and phosphorus oxidation were the major responsive functional processes.Partitioning analysis revealed that N amendment changed bacterial community structure mainly via species loss processes but did not affect bacterial functional communities,with soil pH and ammonium as the key factors influencing changes in bacterial community structure.Conversely,lowered water table altered bacterial and functional communities through species substitution processes linked to soil pH and soil moisture.According to our results,the response mechanisms of microbial communities to lowered water table and N amendment are fundamentally different in alpine wetlands.
基金the National Science and Technology Major Project of the Ministry of Science and Technology of China (2016ZX08001-001)。
文摘A field experiment involving cry1Ab transgenic rice(GM) and its parental non-cry1Ab rice(M) has been on-going since 2014. The diversity of the bacterial communities and the abundance of the microbial functional genes which drive the conversion of nitrogen in paddy soil were analyzed during the growth period of rice in the fifth year of the experiment, using 16 S rRNAbased Illumina Mi Seq and real-time PCR on the amoA, nirS and nirK genes. The results showed no differences in the alpha diversity indexes of the bacterial communities, including Chao1, Shannon and Simpson, between the fields cultivated with line GM and cultivar M at any of the growth stages of rice. However, the bacterial communities in the paddy soil with line GM were separated from those of paddy soil with cultivar M at each of the growth stages of rice, based on the unweighted Uni Frac NMDS or PCoA. In addition, the analyses of ADONIS and ANOSIM, based on the unweighted Uni Frac distance, indicated that the above separations between line GM and cultivar M were statistically significant(P<0.05) during the growth season of rice. The increases in the relative abundances of Acidobacteria or Bacteroidetes, in the paddy soils with line GM or cultivar M, respectively, led to the differences in the bacterial communities between them. At the same time, functional gene prediction based on Illumina Mi Seq data suggested that the abundance of many functional genes increased in the paddy soil with line GM at the maturity stage of rice, such as genes related to the metabolism of starch, amino acids and nitrogen. Otherwise, the copies of bacterial amo A gene, archaeal amo A gene and denitrifying bacterial nir K gene significantly increased(P<0.05 or 0.01) in the paddy soil with line GM. In summary, the release of cry1Ab transgenic rice had effects on either the composition of bacterial communities or the abundance of microbial functional genes in the paddy soil.
