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
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
Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing act...Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.展开更多
Medium-high temperature Daqu is primarily controlled during the production process by regulating environmental temperature and humidity to manage fermentation.In this study,we analyzed the mechanism of regulating the ...Medium-high temperature Daqu is primarily controlled during the production process by regulating environmental temperature and humidity to manage fermentation.In this study,we analyzed the mechanism of regulating the temperature and humidity change rate during the warming period to affect the structure and function of the Daqu microbiota.The results of the study showed that Daqu fermentation occurs in two stages:the temperature increase period(P1),and the combined high temperature and temperature cooling period(P2),with rapid changes in the microbial community structure at the P1 stage,but not significant at the P2 stage.The microbial community structure of Daqu in P1 stage was significantly correlated with environmental factors.Under different rates of temperature and humidity changes,the succession of microbial communities,the breadth of microbial ecological niches along environmental gradients,and the patterns of community assembly differ,resulting in differences in the microbial community structure in Daqu.The slower rate of temperature and humidity change endows Daqu microorganisms with higher species diversity,and makes the abundance of enzymes related to carbohydrate decomposition and volatile metabolite formation in Daqu microorganisms higher,further resulting in a higher content of flavor substances(e.g.Ester content:20 mg/kg at slow rate,4 mg/kg at fast rate).These findings will facilitate more accurate regulation of Daqu production by controlling the rate of temperature and humidity changes during the temperature increase period.展开更多
Koji fermentation accelerates the formation of volatile/non-volatile metabolites in fish sauce,yet the mechanisms underlying its contribution to flavor development remain unclear.Sixteen compounds,including 3-methylbu...Koji fermentation accelerates the formation of volatile/non-volatile metabolites in fish sauce,yet the mechanisms underlying its contribution to flavor development remain unclear.Sixteen compounds,including 3-methylbuta-nal,2-ethylfuran,2-methylbutanal,and eugenol,were identified as key odorants.These key odorants primarily originated from the metabolism of branched-chain,aromatic,and sulfur-containing amino acids,as well as from the oxidation of unsaturated fatty acids(UFAs).Functional enzymes derived from both bacterial and fungal sources participated in the metabolism of flavor precursors.Significant positive correlations were observed between transaminases-key rate-limiting enzymes in amino acid metabolism-and specific bacterial genera(e.g.,Staphylococcus,Stenotrophomonas,Brucella,Mammaliicoccus,Bacillus,and Enterococcus)as well as the fungal genus Aspergillus.The bacterial genus Ligilactobacillus and fungal genera,including Trichoderma,unclassi-fied_k__Fungi,Periconia,Candida,and Apiotrichum,exhibit significant positive correlations with lipoxygenases.Lipoxygenase catalyzes the conversion of UFAs into unstable lipid hydroperoxides,which then degrade into various flavor compounds.These results elucidate potential metabolic mechanisms of functional microorgan-isms,although their functional validation is necessary.This study provides a theoretical foundation for further verification of microbial functions in fish sauce.It also provides a framework for targeted regulation of the functional microbial community and enzymatic interventions aimed at improving product quality.展开更多
The management and treatment of cabin-washing wastewater has received increasing attention in China.To improve the anaerobic degradation of benzene,toluene,ethylbenzene,and xylenes(BTEX) in cabin-washing wastewater,th...The management and treatment of cabin-washing wastewater has received increasing attention in China.To improve the anaerobic degradation of benzene,toluene,ethylbenzene,and xylenes(BTEX) in cabin-washing wastewater,the addition of iron-carbon composite was adopted to enhance the efficiency of anaerobic digestion by facilitating direct interspecies electron transfer(DIET).The preparation of iron-carbon composite was optimized and its effects on BTEX removal and methanogenic performance were then investigated.The results showed that the iron-carbon composite facilitated the hydrolysis and acidification process.The toluene removal rate was improved by 69.9 %,and the cumulative methane yield was enhanced by 90.5 % under the optimized condition of pyrolysis temperature of 600℃,Fe/C mass ratio of 1.0 and dosage of 2.5 g/L.Furthermore,both extracellular electron transfer(EET) and intracellular electron transfer(IET) were found enhanced,and the aromatic compound-degrading bacteria was enriched by iron-carbon composite.The enhanced anaerobic degradation of BTEX by iron-carbon composite provided a novel means for the removal of BTEX from cabin-washing wastewater.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
With the rapid development of molecular biology technology,especially the application of metagenomics,many challenges in groundwater microbial research have been overcome.Metagenomics has enabled the exploration of th...With the rapid development of molecular biology technology,especially the application of metagenomics,many challenges in groundwater microbial research have been overcome.Metagenomics has enabled the exploration of the diversity of unculturable microorganisms in groundwater.This paper reviews macro genomics 16S rRNA and metagenomics sequencing data,highlighting recent applications of metagenomics in investigating groundwater microbial communities.It also examines the relationship between microbial diversity and environmental factors,the identification of functional microbial groups,the role of microorganisms in groundwater pollution remediation,and their contribution to the hydrogeochemi-cal cycle.Finally,it provide insights into future research directions in groundwater microbiology.展开更多
Partitioning of soil organic matter for particulate organic carbon(POC)and mineral-associated organic carbon(MAOC)is essential to understand carbon(C)storage under climate change,given their distinct properties and re...Partitioning of soil organic matter for particulate organic carbon(POC)and mineral-associated organic carbon(MAOC)is essential to understand carbon(C)storage under climate change,given their distinct properties and response to warming.The mechanisms underlying warming-induced changes in C pools in black soils(Mollisols)remain unknown,owing to the stability of C pools and the complexity of their associated microbial communities.This study elucidates POC and MAOC contents and their microbial controls in black soils along a mean annual temperature(MAT)gradient from 0.6 to 7.3℃.The POC content(3.3-17 g kg^(−1))increased with MAT,while MAOC content(33-60 g kg^(−1))decreased,indicating accelerated C turnover with warming.Higher MAT shifted the bacterial communities from K-to r-strategies,aligning with increased POC content.The dominance of r-strategists facilitated rapid utilization and mineralization of organic compounds(e.g.,mainly with low C/N ratio),reducing MAOC and increasing POC through sustained plant residue inputs.This shift towards r-strategists also corresponded with increased abundance of saprotrophic fungi and stronger bacteria-saprotrophic fungi associations.Warming in colder regions may release available organic matter that saprotrophic fungi preferentially utilize over plant residues to minimize energy expenditure,decreasing POC decomposition.Our findings suggest that integrating microbial r-/K-strategies help to elucidate these mechanisms and simplify the interpretation of temperature effects on the dynamics of two main functional pools of soil organic matter.展开更多
Ammonia（NH3） volatilization is one of the primary pathways of nitrogen（N） loss from soils after chemical fertilizer is applied, especially from the alkaline soils in Northern China, which results in lower efficien...Ammonia（NH3） volatilization is one of the primary pathways of nitrogen（N） loss from soils after chemical fertilizer is applied, especially from the alkaline soils in Northern China, which results in lower efficiency for chemical fertilizers. Therefore, we conducted an incubation experiment using an alkaline soil from Tianjin（p H 8.37–8.43） to evaluate the suppression effect of Trichoderma viride（T. viride） biofertilizer on NH3 volatilization, and compared the differences in microbial community structure among all samples. The results showed that viable T. viride biofertilizer（T） decreased NH3 volatilization by 42.21% compared with conventional fertilizer（（CK）, urea）, while nonviable T. viride biofertilizer（TS） decreased NH3 volatilization by 32.42%. NH3 volatilization was significantly higher in CK and sweet potato starch wastewater（SPSW） treatments during the peak period. T. viride biofertilizer also improved the transfer of ammonium from soil to sweet sorghum. Plant dry weights increased 91.23% and 61.08% for T and TS, respectively, compared to CK. Moreover, T. viride biofertilizer enhanced nitrification by increasing the abundance of ammonium-oxidizing archaea（AOA） and ammonium-oxidizing bacteria（AOB）. The results of high-throughput sequencing indicated that the microbial community structure and composition were significantly changed by the application of T. viride biofertilizer. This study demonstrated the immense potential of T. viride biofertilizer in reducing NH3 volatilization from alkaline soil and simultaneously improving the utilization of fertilizer N by sweet sorghum.展开更多
Grassland ecosystems in cold regions are typical of short growing seasons and limited primary productivity,rendering soil microorganisms as major ecosystem engineers in governing biogeochemical cycling.Climate warming...Grassland ecosystems in cold regions are typical of short growing seasons and limited primary productivity,rendering soil microorganisms as major ecosystem engineers in governing biogeochemical cycling.Climate warming and extensive livestock grazing have dramatically influenced soil microbial diversity and function in grassland worldwide,but it remains elusive how functional microbial communities exist and respond to global changes.Here,we present a review to highlight similarities and differences in soil functional microbial communities between alpine grasslands in the Qinghai-Tibet Plateau and temperate grasslands in the Inner Mongolian Plateau,both of which are major plateaus in China,but differ substantially in geography.We show that many specialized functional groups thrive under harsh conditions,exhibiting a high functional diversity.Their community compositions mirror the heterogeneity and complexity of grassland soils.Moreover,functional microbial responses to environmental changes have been extremely variable,with few consistent patterns across both plateaus.Because we identify a lack of technical standardization that prevents in-depth comparative studies for functional microbial communities,we conclude the review by outlining several research gaps that need to be filled in future studies.展开更多
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 the Scientifi c Research Fund of the Second Institute of Oceanography,Ministry of Natural Resources(MNR)(Nos.JB1906,JG1616,JG1910)the Zhejiang Qingshan Lake Innovation Platform for Marine Science and Technology(No.2017E80001)+4 种基金the Key Projects of Philosophy and Social Sciences Research,Ministry of Education(No.18JZD059)the National Key Technology Research and Development Program of the Ministry of Science and Technology of the China(No.2015BAD08B01)the State Key Laboratory of Satellite Ocean Environment Dynamics(No.SOEDZZ1902)the National Natural Science Foundation of China(No.41806136)the Project of Long Term Observation and Research Plan in the Changjiang Estuary and the Adjacent East China Sea(LORCE,14282)。
文摘Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.
基金supported by the Innovation Fund of Postgraduate,Luzhou Laojiao Co.,Ltd.(No.LJCX2023-4)the Project of the Science and Technology Department of Sichuan Province(No.2024ZHCG0094).
文摘Medium-high temperature Daqu is primarily controlled during the production process by regulating environmental temperature and humidity to manage fermentation.In this study,we analyzed the mechanism of regulating the temperature and humidity change rate during the warming period to affect the structure and function of the Daqu microbiota.The results of the study showed that Daqu fermentation occurs in two stages:the temperature increase period(P1),and the combined high temperature and temperature cooling period(P2),with rapid changes in the microbial community structure at the P1 stage,but not significant at the P2 stage.The microbial community structure of Daqu in P1 stage was significantly correlated with environmental factors.Under different rates of temperature and humidity changes,the succession of microbial communities,the breadth of microbial ecological niches along environmental gradients,and the patterns of community assembly differ,resulting in differences in the microbial community structure in Daqu.The slower rate of temperature and humidity change endows Daqu microorganisms with higher species diversity,and makes the abundance of enzymes related to carbohydrate decomposition and volatile metabolite formation in Daqu microorganisms higher,further resulting in a higher content of flavor substances(e.g.Ester content:20 mg/kg at slow rate,4 mg/kg at fast rate).These findings will facilitate more accurate regulation of Daqu production by controlling the rate of temperature and humidity changes during the temperature increase period.
基金supported by The National Key R&D Program of China(2021YFD2100105).
文摘Koji fermentation accelerates the formation of volatile/non-volatile metabolites in fish sauce,yet the mechanisms underlying its contribution to flavor development remain unclear.Sixteen compounds,including 3-methylbuta-nal,2-ethylfuran,2-methylbutanal,and eugenol,were identified as key odorants.These key odorants primarily originated from the metabolism of branched-chain,aromatic,and sulfur-containing amino acids,as well as from the oxidation of unsaturated fatty acids(UFAs).Functional enzymes derived from both bacterial and fungal sources participated in the metabolism of flavor precursors.Significant positive correlations were observed between transaminases-key rate-limiting enzymes in amino acid metabolism-and specific bacterial genera(e.g.,Staphylococcus,Stenotrophomonas,Brucella,Mammaliicoccus,Bacillus,and Enterococcus)as well as the fungal genus Aspergillus.The bacterial genus Ligilactobacillus and fungal genera,including Trichoderma,unclassi-fied_k__Fungi,Periconia,Candida,and Apiotrichum,exhibit significant positive correlations with lipoxygenases.Lipoxygenase catalyzes the conversion of UFAs into unstable lipid hydroperoxides,which then degrade into various flavor compounds.These results elucidate potential metabolic mechanisms of functional microorgan-isms,although their functional validation is necessary.This study provides a theoretical foundation for further verification of microbial functions in fish sauce.It also provides a framework for targeted regulation of the functional microbial community and enzymatic interventions aimed at improving product quality.
基金supported by the National Key Research and Development Program of China(Nos.2022YFC3203403,2022YFC3203401)the Fundamental Research Funds for the Central Universities(No.226-2023-00057).
文摘The management and treatment of cabin-washing wastewater has received increasing attention in China.To improve the anaerobic degradation of benzene,toluene,ethylbenzene,and xylenes(BTEX) in cabin-washing wastewater,the addition of iron-carbon composite was adopted to enhance the efficiency of anaerobic digestion by facilitating direct interspecies electron transfer(DIET).The preparation of iron-carbon composite was optimized and its effects on BTEX removal and methanogenic performance were then investigated.The results showed that the iron-carbon composite facilitated the hydrolysis and acidification process.The toluene removal rate was improved by 69.9 %,and the cumulative methane yield was enhanced by 90.5 % under the optimized condition of pyrolysis temperature of 600℃,Fe/C mass ratio of 1.0 and dosage of 2.5 g/L.Furthermore,both extracellular electron transfer(EET) and intracellular electron transfer(IET) were found enhanced,and the aromatic compound-degrading bacteria was enriched by iron-carbon composite.The enhanced anaerobic degradation of BTEX by iron-carbon composite provided a novel means for the removal of BTEX from cabin-washing wastewater.
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funded by Basic Research Funds of Chinese Academy of Geological Sciences(CSJ-2021-10).
文摘With the rapid development of molecular biology technology,especially the application of metagenomics,many challenges in groundwater microbial research have been overcome.Metagenomics has enabled the exploration of the diversity of unculturable microorganisms in groundwater.This paper reviews macro genomics 16S rRNA and metagenomics sequencing data,highlighting recent applications of metagenomics in investigating groundwater microbial communities.It also examines the relationship between microbial diversity and environmental factors,the identification of functional microbial groups,the role of microorganisms in groundwater pollution remediation,and their contribution to the hydrogeochemi-cal cycle.Finally,it provide insights into future research directions in groundwater microbiology.
基金supported by the National Key Research and Development Program of China[Grant No.2022YFD1500202]Strategic Priority Research Program of the Chinese Academy of Sciences[Grant No.XDA28020202]+1 种基金China Postdoctoral Science Foundation[Grant No.2024M753332]the RUDN University Strategic Academic Leadership Program.
文摘Partitioning of soil organic matter for particulate organic carbon(POC)and mineral-associated organic carbon(MAOC)is essential to understand carbon(C)storage under climate change,given their distinct properties and response to warming.The mechanisms underlying warming-induced changes in C pools in black soils(Mollisols)remain unknown,owing to the stability of C pools and the complexity of their associated microbial communities.This study elucidates POC and MAOC contents and their microbial controls in black soils along a mean annual temperature(MAT)gradient from 0.6 to 7.3℃.The POC content(3.3-17 g kg^(−1))increased with MAT,while MAOC content(33-60 g kg^(−1))decreased,indicating accelerated C turnover with warming.Higher MAT shifted the bacterial communities from K-to r-strategies,aligning with increased POC content.The dominance of r-strategists facilitated rapid utilization and mineralization of organic compounds(e.g.,mainly with low C/N ratio),reducing MAOC and increasing POC through sustained plant residue inputs.This shift towards r-strategists also corresponded with increased abundance of saprotrophic fungi and stronger bacteria-saprotrophic fungi associations.Warming in colder regions may release available organic matter that saprotrophic fungi preferentially utilize over plant residues to minimize energy expenditure,decreasing POC decomposition.Our findings suggest that integrating microbial r-/K-strategies help to elucidate these mechanisms and simplify the interpretation of temperature effects on the dynamics of two main functional pools of soil organic matter.
基金supported by the National Science Fund Projects (Nos. 41371266 and 31670507)Innovation in Cross-functional Team Program of the Chinese Academy of Sciences (No. 2015)+1 种基金the Key Research Program of Chinese Academy of Sciences (No. ZDRW-ZS-2016-5)the Key State Science and Technology Program of China (No. 2015ZX07206-006)
文摘Ammonia（NH3） volatilization is one of the primary pathways of nitrogen（N） loss from soils after chemical fertilizer is applied, especially from the alkaline soils in Northern China, which results in lower efficiency for chemical fertilizers. Therefore, we conducted an incubation experiment using an alkaline soil from Tianjin（p H 8.37–8.43） to evaluate the suppression effect of Trichoderma viride（T. viride） biofertilizer on NH3 volatilization, and compared the differences in microbial community structure among all samples. The results showed that viable T. viride biofertilizer（T） decreased NH3 volatilization by 42.21% compared with conventional fertilizer（（CK）, urea）, while nonviable T. viride biofertilizer（TS） decreased NH3 volatilization by 32.42%. NH3 volatilization was significantly higher in CK and sweet potato starch wastewater（SPSW） treatments during the peak period. T. viride biofertilizer also improved the transfer of ammonium from soil to sweet sorghum. Plant dry weights increased 91.23% and 61.08% for T and TS, respectively, compared to CK. Moreover, T. viride biofertilizer enhanced nitrification by increasing the abundance of ammonium-oxidizing archaea（AOA） and ammonium-oxidizing bacteria（AOB）. The results of high-throughput sequencing indicated that the microbial community structure and composition were significantly changed by the application of T. viride biofertilizer. This study demonstrated the immense potential of T. viride biofertilizer in reducing NH3 volatilization from alkaline soil and simultaneously improving the utilization of fertilizer N by sweet sorghum.
基金supported by the Outstanding Youth Program of the National Natural Science Foundation of China(41825016)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0503).
文摘Grassland ecosystems in cold regions are typical of short growing seasons and limited primary productivity,rendering soil microorganisms as major ecosystem engineers in governing biogeochemical cycling.Climate warming and extensive livestock grazing have dramatically influenced soil microbial diversity and function in grassland worldwide,but it remains elusive how functional microbial communities exist and respond to global changes.Here,we present a review to highlight similarities and differences in soil functional microbial communities between alpine grasslands in the Qinghai-Tibet Plateau and temperate grasslands in the Inner Mongolian Plateau,both of which are major plateaus in China,but differ substantially in geography.We show that many specialized functional groups thrive under harsh conditions,exhibiting a high functional diversity.Their community compositions mirror the heterogeneity and complexity of grassland soils.Moreover,functional microbial responses to environmental changes have been extremely variable,with few consistent patterns across both plateaus.Because we identify a lack of technical standardization that prevents in-depth comparative studies for functional microbial communities,we conclude the review by outlining several research gaps that need to be filled in future studies.
