Cadmium(Cd)contamination in soil can lead to food chain accumulation and greatly impacts on human health.Bioremediation has gained more and more attention due to its environment-friendly,high efficiency and low-cost.I...Cadmium(Cd)contamination in soil can lead to food chain accumulation and greatly impacts on human health.Bioremediation has gained more and more attention due to its environment-friendly,high efficiency and low-cost.In this work,we studied the impact of phosphate solubilizing bacterial agent(PSBA)on Cd bioavailability,microbial communities in soil and Cd accumulation in lettuce plants with pot experiment and field trial.Results of pot experiment showed that PSBA could decrease the bioavailability of Cd(Cd-acid extractable from 3.30 to 2.34mg/kg,Cd-reducible from 1.94 to 1.56 mg/kg),promote lettuce plants growth(increased by 33.85%height and by 33.65%fresh weight)and reduce the accumulation of Cd(from 5.85 to 3.73 mg/kg)in lettuce plants.High-throughput sequencing identified that PSBA could change the composition and structure of the soil microbial communities.The relative abundances of the three ecologically beneficial bacterial families of Pseudomonadaceae,Burkholderiaceae,and Enterobacteriaceae increased from 2.29%to 5.13%,0.56%to 5.24%,and 1.87%to 16.93%,respectively.And the former two were positively correlated with redox potential(Eh)(R^(2)=0.474,p<0.05,R^(2)=0.590,p<0.01,respectively).The bacterial networks were more complex in PSBA treatment,reflecting through more links(from 1893 to 2185)and a higher average degree(from 38.242 to 45.052)and density(from 0.390 to 0.469).Results of field trial demonstrated that PSBA could also decrease Cd content in lettuce plants and microbial composition in soil.This study indicated that PSBA could be served as an alternative material in bioremediation of Cd contamination in soil.展开更多
Ulva prolifera green tides are becoming aworldwide environmental problem,especially in the Yellow Sea,China.However,the effects of the occurrence of U.prolifera green tides on the community organization and stability ...Ulva prolifera green tides are becoming aworldwide environmental problem,especially in the Yellow Sea,China.However,the effects of the occurrence of U.prolifera green tides on the community organization and stability of surrounding microbiomes have still not been de-termined.Here,the prokaryotic microbial community network stability and assembly char-acteristics were systematically analyzed and compared between the green tide and non-green tide periods.U.prolifera blooms weaken the community complexity and robustness of surrounding microbiomes,increasing fragmentation and decreasing diversity.Bacteria and archaea exhibited distinct community distributions and assembly patterns under the influ-ence of green tides,and bacterial communities were more sensitive to outbreaks of green tides.The bacterial communities exhibited a greater niche breadth and a lower phyloge-netic distance during the occurrence of U.prolifera green tides compared to those during the non-green tide period while archaeal communities remained unchanged,suggesting that the bacterial communities underwent stronger homogeneous selection and more sensitive to green tide blooms than the archaeal communities.Piecewise structural equation model analysis revealed that the different responses of major prokaryotic microbial groups,such as Cyanobacteria,to environmental variables during green tides,were influenced by the variations in pH and nitrate during green tides and correlated with the salinity gradient during the non-green tide period.This study elucidates the response of the adaptability,associations,and stability of surrounding microbiomes to outbreaks of U.prolifera green tides.展开更多
Arsenic(As)methylation in soils affects the environmental behavior of As,excessive accumulation of dimethylarsenate(DMA)in rice plants leads to straighthead disease and a serious drop in crop yield.Understanding the m...Arsenic(As)methylation in soils affects the environmental behavior of As,excessive accumulation of dimethylarsenate(DMA)in rice plants leads to straighthead disease and a serious drop in crop yield.Understanding the mobility and transformation of methylated arsenic in redox-changing paddy fields is crucial for food security.Here,soils including unarsenic contaminated(N-As),low-arsenic(L-As),medium-arsenic(M-As),and high-arsenic(H-As)soils were incubated under continuous anoxic,continuous oxic,and consecutive anoxic/oxic treatments respectively,to profile arsenic methylating process and microbial species involved in the As cycle.Under anoxic-oxic(A-O)treatment,methylated arsenic was significantly increased once oxygen was introduced into the incubation system.The methylated arsenic concentrations were up to 2-24 times higher than those in anoxic(A),oxic(O),and oxic-anoxic(O-A)treatments,under which arsenic was methylated slightly and then decreased in all four As concentration soils.In fact,the most plentiful arsenite S-adenosylmethionine methyltransferase genes(arsM)contributed to the increase in As methylation.Proteobacteria(40.8%-62.4%),Firmicutes(3.5%-15.7%),and Desulfobacterota(5.3%-13.3%)were the major microorganisms related to this process.These microbial increasedmarkedly and played more important roles after oxygen was introduced,indicating that they were potential keystone microbial groups for As methylation in the alternating anoxic(flooding)and oxic(drainage)environment.The novel findings provided newinsights into the reoxidation-driven arsenic methylation processes and the model could be used for further risk estimation in periodically flooded paddy fields.展开更多
Crude oil pollution is a significant global environmental challenge.The eastern Gansu Province on the Loess Plateau,an important agricultural region containing the Changqing Oilfield,is facing increasing crude oil con...Crude oil pollution is a significant global environmental challenge.The eastern Gansu Province on the Loess Plateau,an important agricultural region containing the Changqing Oilfield,is facing increasing crude oil contamination.Understanding how microbial communities respond to varying pollution levels is critical for developing effective bioremediation strategies.This study examined how different concentrations of crude oil affect soil properties and microbial communities in Qingyang City,eastern Gansu Province,China by comparing lightly polluted(1895.84-2696.54 mg/kg total petroleum hydrocarbons(TPH)),heavily polluted(4964.25-7153.61 mg/kg TPH),and uncontaminated(CK)soils.Results revealed that petroleum contamination significantly increased total organic carbon(TOC),pH,C:N:P ratio,and the activities of dehydrogenase(DHA)and polyphenol oxidase(PPO),while reducing total nitrogen(TN),available nitrogen(AN),total phosphorus(TP),available phosphorus(AP),available potassium(AK),soil organic matter(SOM),soil water content(SWC),the activities of urease(URE)and alkaline phosphatase(APA),and microbial alpha diversity(P<0.050).Light pollution(LP)soils demonstrated an increase in culturable microorganisms,whereas heavy pollution(HP)soils exhibited increased hydrocarbon-degrading microbes and higher expression of key functional genes,such as alkane monooxygenase(AlkB),cytochrome P450 alkane hydroxylases(P450),catechol 2,3-dioxygenase(C23O),and naphthalene dioxygenase(Nah)(P<0.050).Non-metric multidimensional scaling(NMDS)and redundancy analysis(RDA)indicated evident variations in microbial community structure across different oil contamination levels.LP soils were dominated by bacterial genera Pseudoxanthomonas and Solimonadaceae,whereas Pseudomonas,Nocardioides,and hydrocarbon-degrading genera(Marinobacter,Idiomarina,and Halomonas)were predominant in HP soils.The fungal genus Pseudallescheria exhibited the most pronounced abundance shift between LP and HP soils(P<0.050).Environmental factor analysis identified AN,SWC,TN,SOM,and alpha diversity indices(Shannon index and Chao1 index)as the key differentiators of CK soils,whereas the pollutant levels and metal content were characterized in HP soils.Hydrocarbon-degrading microbial abundance was a defining trait of HP soils.Metabolic pathway analysis revealed enhanced aromatic hydrocarbon degradation in HP soils,indicating microbial adaptation to severe contamination.These findings demonstrated that crude oil pollution suppressed soil nutrients while reshaping the structure and function of microbial communities.Pollution intensity directly affected microbial composition and degradation potential.This study offers valuable insights into microbial responses across contamination gradients and supports the development of targeted bioremediation strategies for oil-contaminated loess soils.展开更多
In recent years,microplastics(MPs)in freshwater lake have been receiving increasing attention;however,the microbial communities on the surface of MPs have not been well studied.To investigate the potential risk posed ...In recent years,microplastics(MPs)in freshwater lake have been receiving increasing attention;however,the microbial communities on the surface of MPs have not been well studied.To investigate the potential risk posed by MPs to the lake ecosystem and its surface microbial community structure,MPs samples were collected in September 2023 in the freshwater Dongting Lake,Hunan,China,at five sites,and the differences in bacterial species community composition and structure between MPs and water samples were analyzed.Results show that MPs(13.71±3.32 items/L)in the samples were mostly black in color,fiber in shape,and PES in composition,and those<0.5 mm in size are dominant.The bacterial composition in water was different from that on MPs.At phylum level,Proteobacteria,Actinobacteria,Cyanobacteria,and Bacteroidetes were dominated in relative abundance in both water and MPs.Proteobacteria was more abundant in MPs than in water.The relative abundance of Bacteroidota and Actinobacteriota was significantly lower in MPs than in water.At genus level,Pantoea and Pseudomonas were potentially pathogenic genera in MPs surfaces.The presence of Cyanobacteria and pathogenic bacteria is undoubtedly a potential risk to the deterioration of the water quality.This study revealed the difference in the distribution of bacterial community in water and MPs in Dongting Lake and provided new perspectives to further understanding of MPs pollution in freshwater lakes.展开更多
Validamycin is often used to control the diseases caused by Rhizoctonia.To investigate the changes of phyllosphere microbial communities after the application of validamycin,we employed high-throughput sequencing to s...Validamycin is often used to control the diseases caused by Rhizoctonia.To investigate the changes of phyllosphere microbial communities after the application of validamycin,we employed high-throughput sequencing to study the structure and diversity of phyllosphere microbial communities of diseased and healthy tobacco leaves.The results showed that the phyllosphere microbial community structure and diversity altered significantly after the application of validamycin.The diseased leaves showed a decline in Shannon index and rises in ACE and Chao1 indexes.The healthy leaves showed no significant change in Shannon index and increases in ACE and Chao1 indexes.The dominant genera in diseased tobacco leaves were Pseudomonas,Enterobacter,Agrobacterium,and Stenotrophomonas,which showed higher relative abundance than those in healthy leaves.After the application of validamycin,diseased tobacco leaves showcased decreased relative abundance of Pseudomonas and Enterobacter and increased relative abundance of Agrobacterium and Methylobacterium,while healthy leaves showed reduced relative abundance of Methylobacterium.The KEGG pathway enrichment analysis showed that the pathways of phyllosphere bacteria of diseased and healthy tobacco leaves mainly had two categories of metabolism and genetic information processing,with differences in relative abundance.The results revealed the changes of phyllosphere microbial community structure and diversity after the application of validamycin and provided a reference for delving into the microecological mechanism of plant disease prevention and control by fungicides.展开更多
Evaluating petroleum contamination risk and implementing remedial measures in agricultural soil rely on indicators such as soil metal(loid)s and microbiome alterations.However,the response of these indicators to petro...Evaluating petroleum contamination risk and implementing remedial measures in agricultural soil rely on indicators such as soil metal(loid)s and microbiome alterations.However,the response of these indicators to petroleum contamination remains under-investigated.The present study investigated the soil physicochemical features,metal(loid)s,microbial communities and networks,and phospholipid fatty acids(PLFAs)community structures in soil samples collected from long-(LC)and short-term(SC)petroleum-contaminated oil fields.The results showed that petroleum contamination increased the levels of soil total petroleum hydrocarbon,carbon,nitrogen,sulfur,phosphorus,calcium,copper,manganese,lead,and zinc,and decreased soil pH,microbial biomass,bacterial and fungal diversity.Petroleum led to a rise in the abundances of soil Proteobacteria,Ascomycota,Oleibacter,and Fusarium.Network analyses showed that the number of network links(Control vs.SC,LC=1181 vs.700,1021),nodes(Control vs.SC,LC=90 vs.71,83)and average degree(Control vs.SC,LC=26.244 vs.19.718,24.602)recovered as the duration of contamination increased.Petroleum contamination also reduced the concentration of soil PLFAs,especially bacterial.These results demonstrate that brief exposure to high levels of petroleum contamination alters the physicochemical characteristics of the soil as well as the composition of soil metal(loid)s andmicroorganisms,leading to a less diverse soilmicrobial network that is more susceptible to damage.Future research should focus on the culturable microbiome of soil under petroleum contamination to provide a theoretical basis for further remediation.展开更多
Reservoirs tend to have enhanced methylmercury（MeHg） concentrations compared to natural lakes and rivers, and water level fluctuations can promote MeHg production. Until now, little research has been conducted on th...Reservoirs tend to have enhanced methylmercury（MeHg） concentrations compared to natural lakes and rivers, and water level fluctuations can promote MeHg production. Until now, little research has been conducted on the effects of microorganisms in soils for the formation of MeHg during different drying and flooding alternating conditions in the Three Gorges Reservoir（TGR）. This study aimed to understand how water level fluctuations affect soil microbial composition and mercury concentrations, and if such microbial variations are related to Hg methylation. The results showed that MeHg concentrations and the ratios of MeHg to THg（MeHg%） in soils were higher in the seasonally drying and flooding alternating areas（DFAs, 175–155 m） than those in the non-inundated（NIAs, 〉 175 m） and inundated areas（IAs, 〈 145 m）. However, MeHg% in all samples was less than 1%, indicating that the Hg methylation activity in the soils of the TGR was under a low level. 454 highthroughput sequencing of 16 S rRNA gene amplicons showed that soil bacterial abundance and diversity were relatively higher in DFA compared to those in NIA and IA, and microbial community composition varied in these three areas. At the family level, those groups in Deltaproteobacteria and Methanomicrobia that might have many Hg methylators were also showed a higher relative abundance in DFA, which might be the reason for the higher MeHg production in these areas. Overall, our results suggested that seasonally water level fluctuations can enhance the microbial abundance and diversity, as well as MeHg production in the TGR.展开更多
Anaerobic digestion (AD) of swine manure (SM) commonly shows low biogas output and unsatisfactory economic performance. In this study, thermophilic AD (TAD, 50±1℃) was combined with thermal hydrolysis pretreatme...Anaerobic digestion (AD) of swine manure (SM) commonly shows low biogas output and unsatisfactory economic performance. In this study, thermophilic AD (TAD, 50±1℃) was combined with thermal hydrolysis pretreatment (THP, 170℃/10 bar), to investigate its potential for maximizing biogas yield, securing successful digestion and microbial diversity, as well as improving energy balance. Four lab-scale continuously stirred tank reactors were operated for 300 days and compared with each other, i.e., reactor 1 (raw SM fed in mesophilic AD:RSM-MAD), reactor 2 (THP-treated SM fed in MAD:TSM-MAD), reactor 3 (RSM-TAD),and reactor 4 (TSM-TAD). The results showed that THP was efficient to increase methane production of SM, TSM-TAD mode led to the highest methane yield (129.8±40.5 mL-CH_(4)/gVS/day) among the tests (p <0.05). Although TAD was more likely to induce free ammonia (> 700 mg/L) or volatile fatty acids (> 6000 mg/L) accumulation compared with MAD in start-up phase, TSM-TAD treatment mode behaved a sustainable digestion process in a long-term operation. For TSM-TAD scenario, higher Shannon–Weaver (3.873) and lower Simpson index (0.061) indicated this mode ensured and enlarged the diversity of bacteria communities. Phylum Bathyarchaeota was dominant (59.3%-90.0%) in archaea community,followed by Euryarchaeota in the four reactors. RSM-MAD treatment mode achieved the highest energy output (4.65 GJ/day), TSM-TAD was less effective (-17.38 GJ/day) due to increased energy demands. Thus improving the energetic efficiency of THP units is recommended for the development of TSM-TAD treatment mode.展开更多
In this study, the effects of bio-organic fertilizer with antagonistic bacteria against tobacco bacterial wilt on soil microbial communities and disease resist- ance of tobacco were investigated by field experiment. T...In this study, the effects of bio-organic fertilizer with antagonistic bacteria against tobacco bacterial wilt on soil microbial communities and disease resist- ance of tobacco were investigated by field experiment. The results showed that the incidence of tobacco bacterial wilt in bio-organic fertilizer treatments （T3 and T4） decreased remarkably among four treatments in the field. Compared with the local conventional fertilization group, the incidence of tobacco bacterial wilt was re- duced by 21.9% and 25.0% in T3 and T4, respectively ; the yield of flue-cured tobacco was improved by 5.7% and 5.3%, respectively ; the proportion of mid- high grade tobacco leaves increased by 2.3% and 2.6%, respectively. After application of bio-organie fertilizer with antagonistic bacteria against tobacco bacterial wilt, rhizosphere soil microbial communities exhibited vast amount and abundant species ; the amount of rhizosphere soil bacteria of infected tobacco plants was im- proved by 218.5% with fewer species. It could be concluded that the application of bio-organic fertilizer with antagonistic bacteria against tobacco bacterial wilt could improve the ecological environment of tobacco field, inhibit the growth of pathogenic bacteria, decrease the incidence of tobacco bacterial wilt, and enhance the quality of flue-cured tobacco. This study laid the foundation for further ecological prevention and control of soil-borne diseases of tobacco.展开更多
The wetlands on the Zoige Plateau have experienced serious degradation,with most of the original marsh being converted to marsh meadow or meadow.Based on the 3 wetland degradation stages,we determined the effects of w...The wetlands on the Zoige Plateau have experienced serious degradation,with most of the original marsh being converted to marsh meadow or meadow.Based on the 3 wetland degradation stages,we determined the effects of wetland degradation on the structure and relative abundance of nitrogencycling(nitrogen-fixing,ammonia-oxidizing,and denitrifying) microbial communities in 3 soil types(intact wetland:marsh soil;early degrading wetland:marsh meadow soil;and degraded wetland:meadow soil) using 454-pyrosequencing.The structure and relative abundance of nitrogen-cycling microbial communities differed in the 3 soil types.Proteobacteria was the predominant phylum in most soil samples but the most abundant soil nitrogenfixing and denitrifying microbial bacteria differed at the class,order,family,and genus levels among the 3soil types.At the genus level,the majority of nitrogenfixing bacterium sequences related to Bradyrhizobium were from marsh and marsh meadow soils;whereas those related to Geobacter originated from meadow soil.The majority of ammonia-oxidizing bacterium sequences related to Nitrosospira were from marsh(except for the 40-60 cm layer),marsh meadow and meadow soils;whereas those related to Candidatus Solibacter originated from 40-60 cm layer of marsh soil.The majority of denitrifying bacterium sequences related to Candidatus Solibacter and Anaeromyxobacter were from marsh and meadow soils;whereas those related to Herbaspirillum originated from meadow soil.The distribution of operational taxonomic units(OTUs)and species were correlated with soil type based upon Venn and Principal Coordinates Analysis(PCoA).Changes in soil type,caused by different water regimes were the most important factors influencing compositional changes in the nitrogen-fixing,ammonia-oxidizing,and denitrifying microbial communities.展开更多
Microorganisms play an important role in removing pollutants from constructed wetlands. We investigated the microbial characteristics in a novel integrated vertical-flow constructed wetland （IVCW）, which has been in...Microorganisms play an important role in removing pollutants from constructed wetlands. We investigated the microbial characteristics in a novel integrated vertical-flow constructed wetland （IVCW）, which has been in operation in Wuhan, China since 1998. We used phospholipid fatty acid （PLFA） and amoA gene to analyze the structure and diversity of the microbial community within the IVCW. PLFA results suggested that the amount of bacterial PLFA was significantly higher than that of fungal PLFA, but the total microbial biomass represented by PLFA index was low in the system. Microbial spatial distribution showed significantly higher bacterial （both G^＋ and G^-） and fungal biomass in the surface than in the subsurface layers. The ratios of monounsaturated to branched PLFA demonstrated that an anaerobic layer sandwiched by two aerobic layers existed in the IVCW, consistent with the redox potential results. Analysis of the amoA revealed the presence of Nitrosomonas-like sequences in the surface substrate of the downflow chamber and apparent diversities of ammonia-oxidizing bacteria in the system. These results suggest that microorganisms, despite their relatively low biomass, have inhabited the IVCW, and the results will offer some valuable information on microbe to system designers and managers.展开更多
Heavy metal pollution has received increasing attention in recent years mainly because of the public awareness of environmental issues. In this study we have evaluated the effect of cadmium （Cd） on enzymes activity,...Heavy metal pollution has received increasing attention in recent years mainly because of the public awareness of environmental issues. In this study we have evaluated the effect of cadmium （Cd） on enzymes activity, substrate utilization pattern and diversity of microbial communities in soil spiked with 0, 20, 40, 60, 80, and 100 mg/kg Cd, during 60 d of incubation at 25℃. Enzyme activities determined at 0, 15, 30, 45, and 60 d after heavy metal application（DAA） showed marked declines for various Cd treatments, and up to 60 DAA, 100 mg/kg Cd resulted in 50.1%, 47.4%, and 39.8% decreases in soil urease, acid phosphatase and dehydrogenase activities, respectively to control. At 60 DAA, substrate utilization pattern of soil microbial communities determined by inoculating Biolog ECO plates indicated that Cd addition had markedly inhibited the functional activity of soil microbial communities and multivariate analysis of sole carbon source utilization showed significantly different utilization patterns for 80 and 100 mg/kg Cd treatments. The structural diversity of soil microbial communities assessed by PCR-DGGE method at 60 DAA, illustrated that DGGE patterns in soil simplified with increasing Cd concentration, and clustering of DGGE profiles for various Cd treatments revealed that they had more than 50% difference with that of control.展开更多
The effects of supplementing 50%of the mineral N fertilizer with organic fertilizer on the metabolism and diversity of soil microbial communities in an oat field were investigated using Biolog-Eco plates.The experimen...The effects of supplementing 50%of the mineral N fertilizer with organic fertilizer on the metabolism and diversity of soil microbial communities in an oat field were investigated using Biolog-Eco plates.The experiment consisted of five treatments:no fertilizer(CK),mineral N fertilizer applied at 90 and 45 kg ha^(-1) N in the form of urea(U1 and U2,respectively),and U2 supplemented with organic fertilizer in the form of sheep manure at 90 and 45 kg ha^(-1) N(U2OM1 and U2OM2,respectively).Each treatment had three replications.The experiment was conducted in 2018 and 2019 in Pinglu District,Shanxi Province,China.The carbon source utilization by soil microbial communities,such as amino acids,amines,carbohydrates,carboxylic acids,and polymers,increased when 50%of the mineral N fertilizer was replaced with organic fertilizer in both years.This result was accompanied by increased richness,dominance,and evenness of the microbial communities.The utilization of amino acid,amine,and carboxylic acid carbon sources and community evenness were further improved when the organic fertilizer amount was doubled in both years.Biplot analysis indicated that amines and amino acids were the most representative of the total carbon source utilization by the soil microbial communities in both years.The highest oat yield was achieved at a total N application rate of 135 kg ha^(-1) in the treatment involving 45 kg ha^(-1) N in the form of urea and 90 kg ha^(-1) N in the form of sheep manure in both years.It was concluded that the application of 50%of the conventional rate of mineral N fertilizer supplemented with an appropriate rate of organic fertilizer enhanced both the functional diversity of soil microbial communities and oat yield.Amine and amino acid carbon sources may be used as a substitute for total carbon sources for assessing total carbon source utilization by soil microbial communities in oat fields in future studies.展开更多
Background: The interaction of the gut microbiota with key metabolic and physiological processes may be associated with poor growth outcomes in animals born with intrauterine growth restriction(IUGR).Results: Growth p...Background: The interaction of the gut microbiota with key metabolic and physiological processes may be associated with poor growth outcomes in animals born with intrauterine growth restriction(IUGR).Results: Growth performance, plasma hormone concentrations, and intestinal microbiota composition were analyzed in IUGR pigs and in normal birth weight(NBW) pigs when the NBW pigs reached 25, 50, and 100 kg of body weight(BW). Compared to NBW pigs, IUGR pigs had lower initial, weaned, and final BW, and lower average daily gain and average daily feed intake in all the considered time points. In the 25 kg BW group, IUGR pigs had higher concentrations of plasma ghrelin and pancreatic polypeptide(PP), but lower insulin concentration than NBW pigs, while the situation was reversed in the 50 kg BW group. As compared to NBW pigs, IUGR pigs had higher microbial alpha diversity in the jejunum and ileum;in the 50 and 100 kg BW groups, IUGR pigs had higher Firmicutes abundance but lower Proteobacteria abundance in the jejunum, and lower Lactobacillus abundance in the jejunum and ileum;in the 25 kg BW group, IUGR pigs showed higher unclassified Ruminococcaceae abundance in the ileum;and in 25 and 50 kg BW groups, IUGR pigs showed lower Ochrobactrum abundance in the jejunum.Spearman's correlation revealed that Lactobacillus was negatively correlated with growth performance, while unclassified Ruminococcaceae was positively correlated. Predictive metagenomic analysis detected significantly different expression of genes in the intestinal microbiota between IUGR and NBW pigs, suggesting different metabolic capabilities between the two groups.Conclusions: Growing-finishing IUGR pigs showed lower growth performance, higher microbial alpha diversity, and differences in plasma hormone concentrations compared to NBW pigs. Alterations in the abundance of Firmicutes,Proteobacteria, Ruminococcaceae, Lactobacillus, and Ochrobactrum in the small intestine may be associated with IUGR, and may therefore serve as a future target for gut microbiota intervention in growing-finishing IUGR pigs.展开更多
Pollution discharge disturbs the natural functions of water systems. The environmental microbial com-munity composition and diversity are sensitive key indicators to the impact of water pol utant on the microbial ecol...Pollution discharge disturbs the natural functions of water systems. The environmental microbial com-munity composition and diversity are sensitive key indicators to the impact of water pol utant on the microbial ecology system over time. It is meaningful to develop a way to identify the microbial diversity related to heavy metal effects in evaluating river pol ution. Water and sediment samples were col ected from eight sections along the Tiaozi River where wastewater and sewage were discharged from Siping City in northeastern China. The main pollutants contents and microbial communities were analyzed. As the primary metal pol utants, zinc （Zn） and arsenic （As） were recorded at the maximum concentrations of 420 and 5.72 μg/L in the water, and 1704 and 1.92 mg/kg in the sediment, re-spectively. These pollutants posed a threat to the microbial community diversity as only a few species of bacteria and eukaryotes with strong resistance were detected through denaturing gradient gel electrophoresis （DGGE）. Acineto-bacter johnsoni , Clostridium cel ulovorans, and Trichococcus pasteuri were the dominant bacteria in the severely pol uted areas. The massive reproduction of Limnodrilus hoffmeisteri almost depleted the dissolved oxygen （DO） and resulted in the decline of the aerobic bacteria. It was noted that the pollution reduced the microbial diversity but the L. hoffmeisteri mass increased as the dominant community, which led to the overconsuming of DO and anaerobic stinking water bodies. Water quality, concentrations of heavy metals, and the spatial distribution of microbial popula-tions have obvious consistencies, which mean that the heavy metals in the river pose a serious stress on the microorganisms.展开更多
Understanding the impact of biological activities on the soil phosphorus(P)distribution under long-term fertilizer application can facilitate better soil P fertility management.Therefore,the primary objectives of this...Understanding the impact of biological activities on the soil phosphorus(P)distribution under long-term fertilizer application can facilitate better soil P fertility management.Therefore,the primary objectives of this study were to investigate the effect of long-term(since 1981)fertilizer application on the soil P fractions and microbial community and to evaluate correlations between the microbial community structure and P distribution.The following treatments were implemented in a long-term field trial:no fertilization(CK),inorganic N and K(NK),inorganic P and K(PK),inorganic N,P and K(NPK)and manure+NPK(MNPK)fertilization.The study showed that the soil pH,soil organic carbon and total and available N and P concentrations were considerably higher in the MNPK treatment than in the CK treatment.The soil microbial biomass C,N and P concentrations were also significantly higher in the MNPK treatment than in the CK treatment.Among fertilization treatments,theβ-1,4-glucosidase,α-1,4-glucosidase,urease,acid phosphatase and phosphodiesterase activities were the highest in the MNPK treatment.Compared to inorganic fertilization,the MNPK treatment increased the labile soil P fractions and decreased the residual soil P concentration.Continuous fertilization significantly affected the soil microbial composition.The total phospholipid fatty acid(PLFA)concentrations in the NK,PK,NPK and MNPK treatments were 23.3,43.1,48.7 and 87.7%higher,respectively,than in the CK treatment.A significant correlation was observed between the microbial community and soil P fractions.Moreover,the aggregated boosted tree(ABT)model showed that among the various soil biochemical properties,the total PLFA concentration was the factor that most influenced the active P pool,accounting for 35.4%of the relative influence of all soil biochemical properties examined.These findings reveal that combined manure and inorganic fertilizer application is a better approach than applying inorganic fertilizer alone for sustaining long-term P fertility by mediating soil biological activity.展开更多
Knowledge on methanogenic microbial communities associated with the degradation of polycyclic aromatic hydrocarbons(PAHs)is crucial to developing strategies for PAHs bioremediation.In this study,the linkage between th...Knowledge on methanogenic microbial communities associated with the degradation of polycyclic aromatic hydrocarbons(PAHs)is crucial to developing strategies for PAHs bioremediation.In this study,the linkage between the type of PAHs and microbial community structure was fully investigated through 16 S rRNA gene sequencing on four PAH-degrading cultures.Putative degradation products were also detected.Our results indicated that naphthalene(Nap)/2-methylnaphthalene(2-Nap),phenanthrene(Phe)and anthracene(Ant)sculpted different microbial communities.Among them,Nap and 2-Nap selected for similar degrading bacteria(i.e.,Alicycliphilus and Thauera)and methanogens(Methanomethylovorans and Methanobacterium).Nap and 2-Nap were probably activated via carboxylation,producing 2-naphthoic acid.In contrast,Phe and Ant shaped different bacterial and archaeal communities,with Arcobacter and Acinetobacter being Phe-degraders and Thiobacillus Ant-degrader.Methanogenic archaea Methanobacterium and Methanomethylovorans predominated Phe-degrading and Ant-degrading culture,respectively.These findings can improve our understanding of natural PAHs attenuation and provide some guidance for PAHs bioremediation in methanogenic environment.展开更多
Microbial community diversities in the drainage from three mines(Dexing Copper Mine,Qibaoshan Copper Mine and Yaogangxian Tungsten Mine,China)were analyzed using 16S rDNA PCR-RFLP approach.The efficiencies of chalcopy...Microbial community diversities in the drainage from three mines(Dexing Copper Mine,Qibaoshan Copper Mine and Yaogangxian Tungsten Mine,China)were analyzed using 16S rDNA PCR-RFLP approach.The efficiencies of chalcopyrite bioleaching were compared using enrichment of the three cultures.Phylogenetic analysis indicates that the dominant microorganisms are clustered with the Proteobacteria,the remaining is affiliated with Nitrospira,Acidobacteria and Actinobacteria.At the genus level,Acidithiobacillus is the dominant group in both YTW and QBS samples,while Spingomonas is dominant in YGX sample.Moreover,the principal component analysis(PCA)reveals that QBS and YTW have similar geochemical character and microbial communities.The results also show that pH value and tungsten concentration play a key role in microbial community distribution and relative abundance.The bioleaching efficiency of the enrichment cultures from YTW and QBS is similar.After 15 d,the bioleaching rates of low grade chalcopyrite(0.99%)are both up to 99.5% when using 10 g/L pulp density due to the similar microbial composition of YTW and QBS.Moreover,the leaching efficiencies of enrichment cultures containing multiple bioleaching microorganisms are higher than that of pure culture Acidithiobacillus ferrooxidans.展开更多
Illumina sequencing and quantitative PCR(qPCR)based on the 16 S ribosomal RNA(rRNA)gene were conducted to characterize the vertical distribution of bacterial and archaeal communities in the sediments of two sites from...Illumina sequencing and quantitative PCR(qPCR)based on the 16 S ribosomal RNA(rRNA)gene were conducted to characterize the vertical distribution of bacterial and archaeal communities in the sediments of two sites from the South Yellow Sea.Both bacterial and archaeal communities showed a clear stratified distribution with sediment depth.The microbial communities in the upper layers were distinct from those in the deeper layers;the relative abundances of sequences of Thaumarchaeota,Gammaproteobacteria,and Actinobacteria were higher in the upper than in the deeper sediments,whereas the sequences of Bathyarchaeia,Lokiarchaeota,Euryarchaeota,Chloroflexi,and Deltaproteobacteria were relatively more abundant in the deeper sediments.Sediment depth and total organic carbon(TOC)can significantly influence both the bacterial and archaeal communities.Furthermore,bacterial and archaeal groups potentially involved in nitrogen,sulfur,and methane metabolism were detected in both sites.In our study,both ammonia-oxidizing bacteria(Nitrospira)and ammonia-oxidizing archaea(Candidatus Nitrosopumilus)were responsible for ammonia oxidization.Additionally,sulfur-reducing bacteria SEEP-SRB1 forming consortia with anaerobic methane-oxidizing archaea ANME-2 a-2 b were capable of anaerobic methane oxidation(AOM)in the 3400-02 sediment samples.展开更多
基金supported by the Science and Technology Programs of Department of Natural Resources of Zhejiang Province,China(No.2020006)the Zhejiang Provincial Natural Science Foundation of China(No.LGF22D030001)the Key R&D Program of Zhejiang Province,China(No.2021C04020)。
文摘Cadmium(Cd)contamination in soil can lead to food chain accumulation and greatly impacts on human health.Bioremediation has gained more and more attention due to its environment-friendly,high efficiency and low-cost.In this work,we studied the impact of phosphate solubilizing bacterial agent(PSBA)on Cd bioavailability,microbial communities in soil and Cd accumulation in lettuce plants with pot experiment and field trial.Results of pot experiment showed that PSBA could decrease the bioavailability of Cd(Cd-acid extractable from 3.30 to 2.34mg/kg,Cd-reducible from 1.94 to 1.56 mg/kg),promote lettuce plants growth(increased by 33.85%height and by 33.65%fresh weight)and reduce the accumulation of Cd(from 5.85 to 3.73 mg/kg)in lettuce plants.High-throughput sequencing identified that PSBA could change the composition and structure of the soil microbial communities.The relative abundances of the three ecologically beneficial bacterial families of Pseudomonadaceae,Burkholderiaceae,and Enterobacteriaceae increased from 2.29%to 5.13%,0.56%to 5.24%,and 1.87%to 16.93%,respectively.And the former two were positively correlated with redox potential(Eh)(R^(2)=0.474,p<0.05,R^(2)=0.590,p<0.01,respectively).The bacterial networks were more complex in PSBA treatment,reflecting through more links(from 1893 to 2185)and a higher average degree(from 38.242 to 45.052)and density(from 0.390 to 0.469).Results of field trial demonstrated that PSBA could also decrease Cd content in lettuce plants and microbial composition in soil.This study indicated that PSBA could be served as an alternative material in bioremediation of Cd contamination in soil.
基金supported by the National Key Research and Development Program of China(No.2022YFC2807500)Laoshan Laboratory(No.LSKJ202203201)+1 种基金the National Natural Science Foundation of China(Nos.42206147,42120104006 and 42176111)the Natural Science Foundation of Shandong Province(Nos.ZR2022QD046,ZR2021QD051).
文摘Ulva prolifera green tides are becoming aworldwide environmental problem,especially in the Yellow Sea,China.However,the effects of the occurrence of U.prolifera green tides on the community organization and stability of surrounding microbiomes have still not been de-termined.Here,the prokaryotic microbial community network stability and assembly char-acteristics were systematically analyzed and compared between the green tide and non-green tide periods.U.prolifera blooms weaken the community complexity and robustness of surrounding microbiomes,increasing fragmentation and decreasing diversity.Bacteria and archaea exhibited distinct community distributions and assembly patterns under the influ-ence of green tides,and bacterial communities were more sensitive to outbreaks of green tides.The bacterial communities exhibited a greater niche breadth and a lower phyloge-netic distance during the occurrence of U.prolifera green tides compared to those during the non-green tide period while archaeal communities remained unchanged,suggesting that the bacterial communities underwent stronger homogeneous selection and more sensitive to green tide blooms than the archaeal communities.Piecewise structural equation model analysis revealed that the different responses of major prokaryotic microbial groups,such as Cyanobacteria,to environmental variables during green tides,were influenced by the variations in pH and nitrate during green tides and correlated with the salinity gradient during the non-green tide period.This study elucidates the response of the adaptability,associations,and stability of surrounding microbiomes to outbreaks of U.prolifera green tides.
基金supported by the Shandong Province Natural Science Foundation of Major Basic Research Program (No.ZR2020ZD34)the Key Projects of the National Natural Science Foundation of China (No.42230706)+3 种基金the National Natural Science Foundation of China (No.42307164)the China Postdoctoral Science Foundation (Nos.2023TQ0191 and 2023M732060)the Shandong Postdoctoral Science Foundation (No.SDBX2023041)and the Qingdao Postdoctoral Science Foundation (No.QDBSH20230202052).
文摘Arsenic(As)methylation in soils affects the environmental behavior of As,excessive accumulation of dimethylarsenate(DMA)in rice plants leads to straighthead disease and a serious drop in crop yield.Understanding the mobility and transformation of methylated arsenic in redox-changing paddy fields is crucial for food security.Here,soils including unarsenic contaminated(N-As),low-arsenic(L-As),medium-arsenic(M-As),and high-arsenic(H-As)soils were incubated under continuous anoxic,continuous oxic,and consecutive anoxic/oxic treatments respectively,to profile arsenic methylating process and microbial species involved in the As cycle.Under anoxic-oxic(A-O)treatment,methylated arsenic was significantly increased once oxygen was introduced into the incubation system.The methylated arsenic concentrations were up to 2-24 times higher than those in anoxic(A),oxic(O),and oxic-anoxic(O-A)treatments,under which arsenic was methylated slightly and then decreased in all four As concentration soils.In fact,the most plentiful arsenite S-adenosylmethionine methyltransferase genes(arsM)contributed to the increase in As methylation.Proteobacteria(40.8%-62.4%),Firmicutes(3.5%-15.7%),and Desulfobacterota(5.3%-13.3%)were the major microorganisms related to this process.These microbial increasedmarkedly and played more important roles after oxygen was introduced,indicating that they were potential keystone microbial groups for As methylation in the alternating anoxic(flooding)and oxic(drainage)environment.The novel findings provided newinsights into the reoxidation-driven arsenic methylation processes and the model could be used for further risk estimation in periodically flooded paddy fields.
基金supported by the Natural Science Foundation of Gansu Province(23JRRM0752,22JR5RA345,21JR1RM333)the Project of Science and Technology Specialist in Gansu Province(24CXGM002)+2 种基金the National Natural Science Foundation of China(31860148)the Research Fund Project for PhD of Longdong University(XYBYZK2208)the Natural Science Foundation of Longdong University(HXZK2488).
文摘Crude oil pollution is a significant global environmental challenge.The eastern Gansu Province on the Loess Plateau,an important agricultural region containing the Changqing Oilfield,is facing increasing crude oil contamination.Understanding how microbial communities respond to varying pollution levels is critical for developing effective bioremediation strategies.This study examined how different concentrations of crude oil affect soil properties and microbial communities in Qingyang City,eastern Gansu Province,China by comparing lightly polluted(1895.84-2696.54 mg/kg total petroleum hydrocarbons(TPH)),heavily polluted(4964.25-7153.61 mg/kg TPH),and uncontaminated(CK)soils.Results revealed that petroleum contamination significantly increased total organic carbon(TOC),pH,C:N:P ratio,and the activities of dehydrogenase(DHA)and polyphenol oxidase(PPO),while reducing total nitrogen(TN),available nitrogen(AN),total phosphorus(TP),available phosphorus(AP),available potassium(AK),soil organic matter(SOM),soil water content(SWC),the activities of urease(URE)and alkaline phosphatase(APA),and microbial alpha diversity(P<0.050).Light pollution(LP)soils demonstrated an increase in culturable microorganisms,whereas heavy pollution(HP)soils exhibited increased hydrocarbon-degrading microbes and higher expression of key functional genes,such as alkane monooxygenase(AlkB),cytochrome P450 alkane hydroxylases(P450),catechol 2,3-dioxygenase(C23O),and naphthalene dioxygenase(Nah)(P<0.050).Non-metric multidimensional scaling(NMDS)and redundancy analysis(RDA)indicated evident variations in microbial community structure across different oil contamination levels.LP soils were dominated by bacterial genera Pseudoxanthomonas and Solimonadaceae,whereas Pseudomonas,Nocardioides,and hydrocarbon-degrading genera(Marinobacter,Idiomarina,and Halomonas)were predominant in HP soils.The fungal genus Pseudallescheria exhibited the most pronounced abundance shift between LP and HP soils(P<0.050).Environmental factor analysis identified AN,SWC,TN,SOM,and alpha diversity indices(Shannon index and Chao1 index)as the key differentiators of CK soils,whereas the pollutant levels and metal content were characterized in HP soils.Hydrocarbon-degrading microbial abundance was a defining trait of HP soils.Metabolic pathway analysis revealed enhanced aromatic hydrocarbon degradation in HP soils,indicating microbial adaptation to severe contamination.These findings demonstrated that crude oil pollution suppressed soil nutrients while reshaping the structure and function of microbial communities.Pollution intensity directly affected microbial composition and degradation potential.This study offers valuable insights into microbial responses across contamination gradients and supports the development of targeted bioremediation strategies for oil-contaminated loess soils.
基金Supported by the National Natural Science Foundation of China(Nos.52209048,52109083)the Hunan Provincial Natural Science Foundation(Nos.2024JJ5207,2021JJ40100)+1 种基金the Special Fund for Building Chenzhou National Sustainable Development Agenda Innovation Demonstration Zone in Hunan Province(No.2022sfq51)the China National University Student Innovation&Entrepreneurship Development Program(No.S202310536023)。
文摘In recent years,microplastics(MPs)in freshwater lake have been receiving increasing attention;however,the microbial communities on the surface of MPs have not been well studied.To investigate the potential risk posed by MPs to the lake ecosystem and its surface microbial community structure,MPs samples were collected in September 2023 in the freshwater Dongting Lake,Hunan,China,at five sites,and the differences in bacterial species community composition and structure between MPs and water samples were analyzed.Results show that MPs(13.71±3.32 items/L)in the samples were mostly black in color,fiber in shape,and PES in composition,and those<0.5 mm in size are dominant.The bacterial composition in water was different from that on MPs.At phylum level,Proteobacteria,Actinobacteria,Cyanobacteria,and Bacteroidetes were dominated in relative abundance in both water and MPs.Proteobacteria was more abundant in MPs than in water.The relative abundance of Bacteroidota and Actinobacteriota was significantly lower in MPs than in water.At genus level,Pantoea and Pseudomonas were potentially pathogenic genera in MPs surfaces.The presence of Cyanobacteria and pathogenic bacteria is undoubtedly a potential risk to the deterioration of the water quality.This study revealed the difference in the distribution of bacterial community in water and MPs in Dongting Lake and provided new perspectives to further understanding of MPs pollution in freshwater lakes.
文摘Validamycin is often used to control the diseases caused by Rhizoctonia.To investigate the changes of phyllosphere microbial communities after the application of validamycin,we employed high-throughput sequencing to study the structure and diversity of phyllosphere microbial communities of diseased and healthy tobacco leaves.The results showed that the phyllosphere microbial community structure and diversity altered significantly after the application of validamycin.The diseased leaves showed a decline in Shannon index and rises in ACE and Chao1 indexes.The healthy leaves showed no significant change in Shannon index and increases in ACE and Chao1 indexes.The dominant genera in diseased tobacco leaves were Pseudomonas,Enterobacter,Agrobacterium,and Stenotrophomonas,which showed higher relative abundance than those in healthy leaves.After the application of validamycin,diseased tobacco leaves showcased decreased relative abundance of Pseudomonas and Enterobacter and increased relative abundance of Agrobacterium and Methylobacterium,while healthy leaves showed reduced relative abundance of Methylobacterium.The KEGG pathway enrichment analysis showed that the pathways of phyllosphere bacteria of diseased and healthy tobacco leaves mainly had two categories of metabolism and genetic information processing,with differences in relative abundance.The results revealed the changes of phyllosphere microbial community structure and diversity after the application of validamycin and provided a reference for delving into the microecological mechanism of plant disease prevention and control by fungicides.
基金supported by Guangxi Key Research and Development Program(No.AB24010136)the Pre-project from Guangxi Bureau of Geology and Mineral Exploration and Development(No.2024051)Guangxi Geochemistry and Environmental Restoration and Management Research Talent Highland.
文摘Evaluating petroleum contamination risk and implementing remedial measures in agricultural soil rely on indicators such as soil metal(loid)s and microbiome alterations.However,the response of these indicators to petroleum contamination remains under-investigated.The present study investigated the soil physicochemical features,metal(loid)s,microbial communities and networks,and phospholipid fatty acids(PLFAs)community structures in soil samples collected from long-(LC)and short-term(SC)petroleum-contaminated oil fields.The results showed that petroleum contamination increased the levels of soil total petroleum hydrocarbon,carbon,nitrogen,sulfur,phosphorus,calcium,copper,manganese,lead,and zinc,and decreased soil pH,microbial biomass,bacterial and fungal diversity.Petroleum led to a rise in the abundances of soil Proteobacteria,Ascomycota,Oleibacter,and Fusarium.Network analyses showed that the number of network links(Control vs.SC,LC=1181 vs.700,1021),nodes(Control vs.SC,LC=90 vs.71,83)and average degree(Control vs.SC,LC=26.244 vs.19.718,24.602)recovered as the duration of contamination increased.Petroleum contamination also reduced the concentration of soil PLFAs,especially bacterial.These results demonstrate that brief exposure to high levels of petroleum contamination alters the physicochemical characteristics of the soil as well as the composition of soil metal(loid)s andmicroorganisms,leading to a less diverse soilmicrobial network that is more susceptible to damage.Future research should focus on the culturable microbiome of soil under petroleum contamination to provide a theoretical basis for further remediation.
基金supported by the National Natural Science Foundation of China (Nos.41373113,41671469,41773073,and 41573104)the National Key Basic Research Program of China (No.2013CB430004)
文摘Reservoirs tend to have enhanced methylmercury（MeHg） concentrations compared to natural lakes and rivers, and water level fluctuations can promote MeHg production. Until now, little research has been conducted on the effects of microorganisms in soils for the formation of MeHg during different drying and flooding alternating conditions in the Three Gorges Reservoir（TGR）. This study aimed to understand how water level fluctuations affect soil microbial composition and mercury concentrations, and if such microbial variations are related to Hg methylation. The results showed that MeHg concentrations and the ratios of MeHg to THg（MeHg%） in soils were higher in the seasonally drying and flooding alternating areas（DFAs, 175–155 m） than those in the non-inundated（NIAs, 〉 175 m） and inundated areas（IAs, 〈 145 m）. However, MeHg% in all samples was less than 1%, indicating that the Hg methylation activity in the soils of the TGR was under a low level. 454 highthroughput sequencing of 16 S rRNA gene amplicons showed that soil bacterial abundance and diversity were relatively higher in DFA compared to those in NIA and IA, and microbial community composition varied in these three areas. At the family level, those groups in Deltaproteobacteria and Methanomicrobia that might have many Hg methylators were also showed a higher relative abundance in DFA, which might be the reason for the higher MeHg production in these areas. Overall, our results suggested that seasonally water level fluctuations can enhance the microbial abundance and diversity, as well as MeHg production in the TGR.
基金supported by the Science and Technology Support Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT(MSIT)(No. NRF-2019K1A3A9A01000029)the financial support from China Scholarship Council+1 种基金the technical support from BrainKorea21 Four research program of the National Research Foundation of KoreaInstitute of Construction and Environmental Engineering at Seoul National University。
文摘Anaerobic digestion (AD) of swine manure (SM) commonly shows low biogas output and unsatisfactory economic performance. In this study, thermophilic AD (TAD, 50±1℃) was combined with thermal hydrolysis pretreatment (THP, 170℃/10 bar), to investigate its potential for maximizing biogas yield, securing successful digestion and microbial diversity, as well as improving energy balance. Four lab-scale continuously stirred tank reactors were operated for 300 days and compared with each other, i.e., reactor 1 (raw SM fed in mesophilic AD:RSM-MAD), reactor 2 (THP-treated SM fed in MAD:TSM-MAD), reactor 3 (RSM-TAD),and reactor 4 (TSM-TAD). The results showed that THP was efficient to increase methane production of SM, TSM-TAD mode led to the highest methane yield (129.8±40.5 mL-CH_(4)/gVS/day) among the tests (p <0.05). Although TAD was more likely to induce free ammonia (> 700 mg/L) or volatile fatty acids (> 6000 mg/L) accumulation compared with MAD in start-up phase, TSM-TAD treatment mode behaved a sustainable digestion process in a long-term operation. For TSM-TAD scenario, higher Shannon–Weaver (3.873) and lower Simpson index (0.061) indicated this mode ensured and enlarged the diversity of bacteria communities. Phylum Bathyarchaeota was dominant (59.3%-90.0%) in archaea community,followed by Euryarchaeota in the four reactors. RSM-MAD treatment mode achieved the highest energy output (4.65 GJ/day), TSM-TAD was less effective (-17.38 GJ/day) due to increased energy demands. Thus improving the energetic efficiency of THP units is recommended for the development of TSM-TAD treatment mode.
基金Supported by Project of Nanping Tobacco Monopoly Bureau(NYK2012-14-3)
文摘In this study, the effects of bio-organic fertilizer with antagonistic bacteria against tobacco bacterial wilt on soil microbial communities and disease resist- ance of tobacco were investigated by field experiment. The results showed that the incidence of tobacco bacterial wilt in bio-organic fertilizer treatments （T3 and T4） decreased remarkably among four treatments in the field. Compared with the local conventional fertilization group, the incidence of tobacco bacterial wilt was re- duced by 21.9% and 25.0% in T3 and T4, respectively ; the yield of flue-cured tobacco was improved by 5.7% and 5.3%, respectively ; the proportion of mid- high grade tobacco leaves increased by 2.3% and 2.6%, respectively. After application of bio-organie fertilizer with antagonistic bacteria against tobacco bacterial wilt, rhizosphere soil microbial communities exhibited vast amount and abundant species ; the amount of rhizosphere soil bacteria of infected tobacco plants was im- proved by 218.5% with fewer species. It could be concluded that the application of bio-organic fertilizer with antagonistic bacteria against tobacco bacterial wilt could improve the ecological environment of tobacco field, inhibit the growth of pathogenic bacteria, decrease the incidence of tobacco bacterial wilt, and enhance the quality of flue-cured tobacco. This study laid the foundation for further ecological prevention and control of soil-borne diseases of tobacco.
基金financially supported by the 11th Five Years Key Programs for Science and Technology Development of China (Grant No.2007BAC18B03)
文摘The wetlands on the Zoige Plateau have experienced serious degradation,with most of the original marsh being converted to marsh meadow or meadow.Based on the 3 wetland degradation stages,we determined the effects of wetland degradation on the structure and relative abundance of nitrogencycling(nitrogen-fixing,ammonia-oxidizing,and denitrifying) microbial communities in 3 soil types(intact wetland:marsh soil;early degrading wetland:marsh meadow soil;and degraded wetland:meadow soil) using 454-pyrosequencing.The structure and relative abundance of nitrogen-cycling microbial communities differed in the 3 soil types.Proteobacteria was the predominant phylum in most soil samples but the most abundant soil nitrogenfixing and denitrifying microbial bacteria differed at the class,order,family,and genus levels among the 3soil types.At the genus level,the majority of nitrogenfixing bacterium sequences related to Bradyrhizobium were from marsh and marsh meadow soils;whereas those related to Geobacter originated from meadow soil.The majority of ammonia-oxidizing bacterium sequences related to Nitrosospira were from marsh(except for the 40-60 cm layer),marsh meadow and meadow soils;whereas those related to Candidatus Solibacter originated from 40-60 cm layer of marsh soil.The majority of denitrifying bacterium sequences related to Candidatus Solibacter and Anaeromyxobacter were from marsh and meadow soils;whereas those related to Herbaspirillum originated from meadow soil.The distribution of operational taxonomic units(OTUs)and species were correlated with soil type based upon Venn and Principal Coordinates Analysis(PCoA).Changes in soil type,caused by different water regimes were the most important factors influencing compositional changes in the nitrogen-fixing,ammonia-oxidizing,and denitrifying microbial communities.
基金supported by the National High Technology Research and Development Program (863) of China (No.2002AA601021)the National Natural Science Funds for Distinguished Young Scholar in China(No.39925007)the Key Programs for Science and Technology Development of Hubei Province,China(No.2006AA305A03)
文摘Microorganisms play an important role in removing pollutants from constructed wetlands. We investigated the microbial characteristics in a novel integrated vertical-flow constructed wetland （IVCW）, which has been in operation in Wuhan, China since 1998. We used phospholipid fatty acid （PLFA） and amoA gene to analyze the structure and diversity of the microbial community within the IVCW. PLFA results suggested that the amount of bacterial PLFA was significantly higher than that of fungal PLFA, but the total microbial biomass represented by PLFA index was low in the system. Microbial spatial distribution showed significantly higher bacterial （both G^＋ and G^-） and fungal biomass in the surface than in the subsurface layers. The ratios of monounsaturated to branched PLFA demonstrated that an anaerobic layer sandwiched by two aerobic layers existed in the IVCW, consistent with the redox potential results. Analysis of the amoA revealed the presence of Nitrosomonas-like sequences in the surface substrate of the downflow chamber and apparent diversities of ammonia-oxidizing bacteria in the system. These results suggest that microorganisms, despite their relatively low biomass, have inhabited the IVCW, and the results will offer some valuable information on microbe to system designers and managers.
基金The National Basic Research Programof China(2005CB121104) the National Key Project for Science and Technology of China(No.2001BA804A25andthe Natural Science Foundation of Zhejiang Province(Y504128)
文摘Heavy metal pollution has received increasing attention in recent years mainly because of the public awareness of environmental issues. In this study we have evaluated the effect of cadmium （Cd） on enzymes activity, substrate utilization pattern and diversity of microbial communities in soil spiked with 0, 20, 40, 60, 80, and 100 mg/kg Cd, during 60 d of incubation at 25℃. Enzyme activities determined at 0, 15, 30, 45, and 60 d after heavy metal application（DAA） showed marked declines for various Cd treatments, and up to 60 DAA, 100 mg/kg Cd resulted in 50.1%, 47.4%, and 39.8% decreases in soil urease, acid phosphatase and dehydrogenase activities, respectively to control. At 60 DAA, substrate utilization pattern of soil microbial communities determined by inoculating Biolog ECO plates indicated that Cd addition had markedly inhibited the functional activity of soil microbial communities and multivariate analysis of sole carbon source utilization showed significantly different utilization patterns for 80 and 100 mg/kg Cd treatments. The structural diversity of soil microbial communities assessed by PCR-DGGE method at 60 DAA, illustrated that DGGE patterns in soil simplified with increasing Cd concentration, and clustering of DGGE profiles for various Cd treatments revealed that they had more than 50% difference with that of control.
基金This research was supported by the Key Research and Development Program of Shanxi Province,China(201703D211001-03-01 and 201703D211001-03-03)and the Key Research and Development Program of Shanxi Province,China(201903D221061).
文摘The effects of supplementing 50%of the mineral N fertilizer with organic fertilizer on the metabolism and diversity of soil microbial communities in an oat field were investigated using Biolog-Eco plates.The experiment consisted of five treatments:no fertilizer(CK),mineral N fertilizer applied at 90 and 45 kg ha^(-1) N in the form of urea(U1 and U2,respectively),and U2 supplemented with organic fertilizer in the form of sheep manure at 90 and 45 kg ha^(-1) N(U2OM1 and U2OM2,respectively).Each treatment had three replications.The experiment was conducted in 2018 and 2019 in Pinglu District,Shanxi Province,China.The carbon source utilization by soil microbial communities,such as amino acids,amines,carbohydrates,carboxylic acids,and polymers,increased when 50%of the mineral N fertilizer was replaced with organic fertilizer in both years.This result was accompanied by increased richness,dominance,and evenness of the microbial communities.The utilization of amino acid,amine,and carboxylic acid carbon sources and community evenness were further improved when the organic fertilizer amount was doubled in both years.Biplot analysis indicated that amines and amino acids were the most representative of the total carbon source utilization by the soil microbial communities in both years.The highest oat yield was achieved at a total N application rate of 135 kg ha^(-1) in the treatment involving 45 kg ha^(-1) N in the form of urea and 90 kg ha^(-1) N in the form of sheep manure in both years.It was concluded that the application of 50%of the conventional rate of mineral N fertilizer supplemented with an appropriate rate of organic fertilizer enhanced both the functional diversity of soil microbial communities and oat yield.Amine and amino acid carbon sources may be used as a substitute for total carbon sources for assessing total carbon source utilization by soil microbial communities in oat fields in future studies.
基金jointly supported by the National Natural Science Foundation of China (31772613 and 31572421)Special Funds for Construction of Innovative Provinces in Hunan Province (2019RS3022)。
文摘Background: The interaction of the gut microbiota with key metabolic and physiological processes may be associated with poor growth outcomes in animals born with intrauterine growth restriction(IUGR).Results: Growth performance, plasma hormone concentrations, and intestinal microbiota composition were analyzed in IUGR pigs and in normal birth weight(NBW) pigs when the NBW pigs reached 25, 50, and 100 kg of body weight(BW). Compared to NBW pigs, IUGR pigs had lower initial, weaned, and final BW, and lower average daily gain and average daily feed intake in all the considered time points. In the 25 kg BW group, IUGR pigs had higher concentrations of plasma ghrelin and pancreatic polypeptide(PP), but lower insulin concentration than NBW pigs, while the situation was reversed in the 50 kg BW group. As compared to NBW pigs, IUGR pigs had higher microbial alpha diversity in the jejunum and ileum;in the 50 and 100 kg BW groups, IUGR pigs had higher Firmicutes abundance but lower Proteobacteria abundance in the jejunum, and lower Lactobacillus abundance in the jejunum and ileum;in the 25 kg BW group, IUGR pigs showed higher unclassified Ruminococcaceae abundance in the ileum;and in 25 and 50 kg BW groups, IUGR pigs showed lower Ochrobactrum abundance in the jejunum.Spearman's correlation revealed that Lactobacillus was negatively correlated with growth performance, while unclassified Ruminococcaceae was positively correlated. Predictive metagenomic analysis detected significantly different expression of genes in the intestinal microbiota between IUGR and NBW pigs, suggesting different metabolic capabilities between the two groups.Conclusions: Growing-finishing IUGR pigs showed lower growth performance, higher microbial alpha diversity, and differences in plasma hormone concentrations compared to NBW pigs. Alterations in the abundance of Firmicutes,Proteobacteria, Ruminococcaceae, Lactobacillus, and Ochrobactrum in the small intestine may be associated with IUGR, and may therefore serve as a future target for gut microbiota intervention in growing-finishing IUGR pigs.
基金Project supported by the National Science and Technology Majo Project of China(Nos.2008ZX07208-005 and 2012ZX07202-003)
文摘Pollution discharge disturbs the natural functions of water systems. The environmental microbial com-munity composition and diversity are sensitive key indicators to the impact of water pol utant on the microbial ecology system over time. It is meaningful to develop a way to identify the microbial diversity related to heavy metal effects in evaluating river pol ution. Water and sediment samples were col ected from eight sections along the Tiaozi River where wastewater and sewage were discharged from Siping City in northeastern China. The main pollutants contents and microbial communities were analyzed. As the primary metal pol utants, zinc （Zn） and arsenic （As） were recorded at the maximum concentrations of 420 and 5.72 μg/L in the water, and 1704 and 1.92 mg/kg in the sediment, re-spectively. These pollutants posed a threat to the microbial community diversity as only a few species of bacteria and eukaryotes with strong resistance were detected through denaturing gradient gel electrophoresis （DGGE）. Acineto-bacter johnsoni , Clostridium cel ulovorans, and Trichococcus pasteuri were the dominant bacteria in the severely pol uted areas. The massive reproduction of Limnodrilus hoffmeisteri almost depleted the dissolved oxygen （DO） and resulted in the decline of the aerobic bacteria. It was noted that the pollution reduced the microbial diversity but the L. hoffmeisteri mass increased as the dominant community, which led to the overconsuming of DO and anaerobic stinking water bodies. Water quality, concentrations of heavy metals, and the spatial distribution of microbial popula-tions have obvious consistencies, which mean that the heavy metals in the river pose a serious stress on the microorganisms.
基金supported by the National Key Research and Development Program of China(2016YFD0300901)the Fundamental Research Funds for Central Nonprofit Scientific Institutions of China(1610132019035,1610132020023 and 1610132020024)the Natural Science Foundation of Jiangxi Province,China(20192BAB203022)。
文摘Understanding the impact of biological activities on the soil phosphorus(P)distribution under long-term fertilizer application can facilitate better soil P fertility management.Therefore,the primary objectives of this study were to investigate the effect of long-term(since 1981)fertilizer application on the soil P fractions and microbial community and to evaluate correlations between the microbial community structure and P distribution.The following treatments were implemented in a long-term field trial:no fertilization(CK),inorganic N and K(NK),inorganic P and K(PK),inorganic N,P and K(NPK)and manure+NPK(MNPK)fertilization.The study showed that the soil pH,soil organic carbon and total and available N and P concentrations were considerably higher in the MNPK treatment than in the CK treatment.The soil microbial biomass C,N and P concentrations were also significantly higher in the MNPK treatment than in the CK treatment.Among fertilization treatments,theβ-1,4-glucosidase,α-1,4-glucosidase,urease,acid phosphatase and phosphodiesterase activities were the highest in the MNPK treatment.Compared to inorganic fertilization,the MNPK treatment increased the labile soil P fractions and decreased the residual soil P concentration.Continuous fertilization significantly affected the soil microbial composition.The total phospholipid fatty acid(PLFA)concentrations in the NK,PK,NPK and MNPK treatments were 23.3,43.1,48.7 and 87.7%higher,respectively,than in the CK treatment.A significant correlation was observed between the microbial community and soil P fractions.Moreover,the aggregated boosted tree(ABT)model showed that among the various soil biochemical properties,the total PLFA concentration was the factor that most influenced the active P pool,accounting for 35.4%of the relative influence of all soil biochemical properties examined.These findings reveal that combined manure and inorganic fertilizer application is a better approach than applying inorganic fertilizer alone for sustaining long-term P fertility by mediating soil biological activity.
基金supported by the National Natural Science Foundation Projects (Nos. 41573065 and 41773082)the Key Project of Natural Science Foundation of China (No. 21337001)the National Water Pollution Control and Treatment Science and Technology Major Project (No. 2017ZX07202002)
文摘Knowledge on methanogenic microbial communities associated with the degradation of polycyclic aromatic hydrocarbons(PAHs)is crucial to developing strategies for PAHs bioremediation.In this study,the linkage between the type of PAHs and microbial community structure was fully investigated through 16 S rRNA gene sequencing on four PAH-degrading cultures.Putative degradation products were also detected.Our results indicated that naphthalene(Nap)/2-methylnaphthalene(2-Nap),phenanthrene(Phe)and anthracene(Ant)sculpted different microbial communities.Among them,Nap and 2-Nap selected for similar degrading bacteria(i.e.,Alicycliphilus and Thauera)and methanogens(Methanomethylovorans and Methanobacterium).Nap and 2-Nap were probably activated via carboxylation,producing 2-naphthoic acid.In contrast,Phe and Ant shaped different bacterial and archaeal communities,with Arcobacter and Acinetobacter being Phe-degraders and Thiobacillus Ant-degrader.Methanogenic archaea Methanobacterium and Methanomethylovorans predominated Phe-degrading and Ant-degrading culture,respectively.These findings can improve our understanding of natural PAHs attenuation and provide some guidance for PAHs bioremediation in methanogenic environment.
基金Project(50621063) supported by the National Natural Science Foundation of ChinaProject (2004CB619204) supported by the National Basic Research and Development Program of China
文摘Microbial community diversities in the drainage from three mines(Dexing Copper Mine,Qibaoshan Copper Mine and Yaogangxian Tungsten Mine,China)were analyzed using 16S rDNA PCR-RFLP approach.The efficiencies of chalcopyrite bioleaching were compared using enrichment of the three cultures.Phylogenetic analysis indicates that the dominant microorganisms are clustered with the Proteobacteria,the remaining is affiliated with Nitrospira,Acidobacteria and Actinobacteria.At the genus level,Acidithiobacillus is the dominant group in both YTW and QBS samples,while Spingomonas is dominant in YGX sample.Moreover,the principal component analysis(PCA)reveals that QBS and YTW have similar geochemical character and microbial communities.The results also show that pH value and tungsten concentration play a key role in microbial community distribution and relative abundance.The bioleaching efficiency of the enrichment cultures from YTW and QBS is similar.After 15 d,the bioleaching rates of low grade chalcopyrite(0.99%)are both up to 99.5% when using 10 g/L pulp density due to the similar microbial composition of YTW and QBS.Moreover,the leaching efficiencies of enrichment cultures containing multiple bioleaching microorganisms are higher than that of pure culture Acidithiobacillus ferrooxidans.
基金Supported by the National Key Research and Development Program of China(No.2017YFC1404402)the National Natural Science Foundation of China(Nos.41620104001,41806131)+1 种基金the Scientific and Technological Innovation Project of the Qingdao National Laboratory for Marine Science and Technology(No.2016ASKJ02)the China Postdoctoral Science Foundation(No.2018M632722)。
文摘Illumina sequencing and quantitative PCR(qPCR)based on the 16 S ribosomal RNA(rRNA)gene were conducted to characterize the vertical distribution of bacterial and archaeal communities in the sediments of two sites from the South Yellow Sea.Both bacterial and archaeal communities showed a clear stratified distribution with sediment depth.The microbial communities in the upper layers were distinct from those in the deeper layers;the relative abundances of sequences of Thaumarchaeota,Gammaproteobacteria,and Actinobacteria were higher in the upper than in the deeper sediments,whereas the sequences of Bathyarchaeia,Lokiarchaeota,Euryarchaeota,Chloroflexi,and Deltaproteobacteria were relatively more abundant in the deeper sediments.Sediment depth and total organic carbon(TOC)can significantly influence both the bacterial and archaeal communities.Furthermore,bacterial and archaeal groups potentially involved in nitrogen,sulfur,and methane metabolism were detected in both sites.In our study,both ammonia-oxidizing bacteria(Nitrospira)and ammonia-oxidizing archaea(Candidatus Nitrosopumilus)were responsible for ammonia oxidization.Additionally,sulfur-reducing bacteria SEEP-SRB1 forming consortia with anaerobic methane-oxidizing archaea ANME-2 a-2 b were capable of anaerobic methane oxidation(AOM)in the 3400-02 sediment samples.
