In order to implement industrial production of selected functional bacteria for bioremediation of shrimp culture environment, the fermentation conditions of the three functional bacteria, which have high ability in de...In order to implement industrial production of selected functional bacteria for bioremediation of shrimp culture environment, the fermentation conditions of the three functional bacteria, which have high ability in degrading organic pollutants at the bottom of shrimp ponds, were studied. The results showed that the favorable fermentation medium （per L） was 25 g of peptone, 5 g of yeast extract, and 0.2 g of ferric phosphate, and the initial pH value of the medium was 8.0. The optimum fermentation time was 20 h. The optimum stirring way was stirring one hour after one hour. Iso-electric point sedimentation collecting method was the most efficient and economic method to collect the bacteria cells after fermentation, with the optimum sediment pH of 3.67, 4.02, and 3.40 for the strains Lt7222, Gy7018 and Lt7511,respectively. It was also indicated that the survival and reproducing ability of the bacterial cells were not affected by the sedimentation process.展开更多
After the single-strain abilities of organic-pollutant-degrading bacteria in bioremediation of sediment environment of shrimp culture are determined, the multi- strain degrading effect of the compositions of different...After the single-strain abilities of organic-pollutant-degrading bacteria in bioremediation of sediment environment of shrimp culture are determined, the multi- strain degrading effect of the compositions of different strains is measured. The results indicate that the multi-strains groups have higher degrading ability than the single -strain groups. Three-strain groups are better than two-strain groups, and four-strain groups are better than three-strain groups and five-strain groups, the groups composed of strains Lt7222, Lt7511, Fc6308 and Gy7018 has the best degrading effect, the CODMn removal rate is 73.2 % in 66 h, and gets to 82.7 % in 114 h, 30 % higher than that of the best single-strain group; Groups of Lt7222, Lt7511, Lt7451 and Gy7018 are the second, whose CODMn removal rate is 82.1 % in 114 h. It is suggested that multi-species bacteria be used as functional bacteria in bioremediation of mariculture environment.展开更多
Fecal microbiota transplantation(FMT),also known as fecal bacterial therapy,is a treatment option that can quickly reconstruct the normal composition of intestinal microbes,and it has a good therapeutic effect on Clos...Fecal microbiota transplantation(FMT),also known as fecal bacterial therapy,is a treatment option that can quickly reconstruct the normal composition of intestinal microbes,and it has a good therapeutic effect on Clostridium difficile infection,as well as on other microecological disorders.However,the causal mechanism of FMT efficacy remains to be clarified,its safety is a major problem,and the standardization and acceptability of FMT need to be improved.This review summarizes its current research status and potential research areas that need to be strengthened,and proposes to clarify the safety of FMT and the causal relationship between FMT and therapeutic effectiveness based on germ-free animals.Meanwhile,the research system is combined with multiomics technology to screen the effective bacteria in FMT,and develop standard,safe,effective and controllable flora of FMT.展开更多
A total of 50 endophytic bacterial isolates were obtained from Kobreasia capillifolia at alpine grasslands in the Eastern Qilian Mountains on the Tibetan Plateau in China. Based on the sequencing and phylogenetic anal...A total of 50 endophytic bacterial isolates were obtained from Kobreasia capillifolia at alpine grasslands in the Eastern Qilian Mountains on the Tibetan Plateau in China. Based on the sequencing and phylogenetic analysis of 16 S r DNA genes, all isolates phylogenetically related closely to Bacillus, Acinetobacter, Stenotrophomonas, Brevundimonas, Arthrobacter, Curtobacterium, Paenibacillus, Plantibacter, Promicromonospora, Serratia, and Microbacterium, among which Bacillus was the predominant genus（47.8% of the total number of endophytic isolates）. These isolates possessed different biological functions. In 50 endophytic bacteria, 42 isolates produced indole acetic acid（IAA） on King medium. There were seven isolates showing potency of mineral phosphate solubilization in Pikovaskaia＇s（PKO） liquid medium. Seven isolates exhibited antagonistic effect against Fusarium avenaceum, Colletotrichum coccodes and Phoma foveata. This was the first report on diversity and plant growth promotion of endophytic bacteria from K. capillifolia on alpine grassland in the Eastern Qilian Mountains, Chain. It is essential for revealing the relationship among plant, microorganism, and the special environment because the potential function of endophytic bacteria made a contribution to the interactions of plants and endophytic bacteria.展开更多
Small diameter gravity sewers(SDGS)are extensively used to collect rural sewage as they are low in cost and quick to construct.However,the characteristics of biofilms in rural SDGS are still not clear.In this study,bi...Small diameter gravity sewers(SDGS)are extensively used to collect rural sewage as they are low in cost and quick to construct.However,the characteristics of biofilms in rural SDGS are still not clear.In this study,biofilms characteristics of aerobic rural SDGS were investigated using simulations in a lab under different flow conditions and slopes.Results indic ated that the average thickness of aerobic rural SDGS biofilms was in the range of 350-650μm,decreasing at locations with variable flow and high slopes.Protein was the most abundant substance in extracellular polymeric substance of SDGS biofilms.The most abundant bacteria,Proteobacteria,Actinobacteria,and Bacteroidetes,and functional bacteria showed different distributions when analyzed through Illumina HiSeq sequencing of 16 S rRNA.The relative abundances of denitrifying bacteria,nitrite-oxidizing bacteria,and sulfate-reducing bacteria(SRB)were lower during variable flow than during stable flow.High slopes(15‰)decreased SRB presence,which could be used to mitigate H2 S accumulation in aerobic SDGS.Overall,this study describes the characteristics of aerobic rural SDGS biofilms and provides valuable suggestions for the optimal design of SDGS based on these characteristics.展开更多
Understanding the structures and dynamics of bacterial communities in activated sludge(AS)in full-scale wastewater treatment plants(WWTPs)is of both engineering and ecological significance.Previous investigations have...Understanding the structures and dynamics of bacterial communities in activated sludge(AS)in full-scale wastewater treatment plants(WWTPs)is of both engineering and ecological significance.Previous investigations have mainly focused on the AS communities of WWTP aeration tanks,and the differences and interactions between the communities in anaerobic and anoxic tanks of the AS system remain poorly understood.Here,we investigated the structures of bacterial communities and their inter-connections in three tanks(anaerobic,anoxic,and aerobic)and influent from a full-scale WWTP with conventional anaerobic/anoxic/aerobic(A/A/O)process over a year to explore their functionality and network differentiation.High-throughput sequencing showed that community compositions did not differ appreciably between the different tanks,likely due to the continuous sludge community interchange between tanks.However,network analysis showed significant differences in inter-species relationships,OTU topological roles,and keystone populations in the different AS communities.Moreover,the anoxic network is expected to be more unstable and easily affected by environmental disturbance.Tank-associated environmental factors,including dissolved oxygen,pH,and nutrients,were found to affect the relative abundance of functional genera(i.e.,AOB,NOB,PAOs,and denitrifiers),suggesting that these groups were more susceptible to environmental variables than other bacteria.Therefore,this work could assist in improving our understanding of tank-associated microbial ecology,particularly the response of functional bacteria to seasonal variations in WWTPs employing A/A/O process.展开更多
Alfalfa is a perennial herbaceous forage legume that is remarkably and negatively affected by monocropping.However,the contribution of the changes in bacterial communities to soil sickness in alfalfa have not been elu...Alfalfa is a perennial herbaceous forage legume that is remarkably and negatively affected by monocropping.However,the contribution of the changes in bacterial communities to soil sickness in alfalfa have not been elucidated.Therefore,we investigated bacterial community structures in response to monocropped alfalfa along the chronosequence.Continuous cropping remarkably reduced bacterial alpha diversity and altered community structures,and soil pH,total P and available P were strongly associated with the changes of bacterial diversity and community structures.Intriguingly,10 years of monocropped alfalfa might be a demarcation point separating soil bacterial community structures into two obvious groups that containing soil samples collected in less and more than 10 years.The relative abundances of copiotrophic bacteria of Actinobacteria and Gammaproteobacteria significantly increased with the extension of continuous cropping years,while the oligotrophic bacteria of Armatimonadetes,Chloroflexi,Firmicutes and Gemmatimonadetes showed the opposite changing patterns.Among those altered phyla,Actinobacteria,Chloroflexi,Alphaproteobacteria and Acidobacteria were the most important bacteria which contributed 50.86%of the community variations. Additionally, the relative abundances of nitrogen fixation bacteria ofBradyrhizobium and Mesorhizobium obviously increased with continuous cropping years, while theabundances of Arthrobacter, Bacillus, Burkholderiaceae and Microbacterium with potential functionsof solubilizing phosphorus and potassium remarkably decreased after long-term continuouscropping. Furthermore, bacterial cooccurrence patterns were significantly influenced by continuouscropping years, with long-term monocropped alfalfa simplifying the complexity of the cooccurrencenetworks. These findings enhanced our understandings and provided references for forecasting howsoil bacterial communities responds to monocropped alfalfa.展开更多
Freshwater salinization is receiving increasing global attention due to its profound influence on nitrogen cycling in aquatic ecosystems and the accessibility of water resources.However,a comprehensive understanding o...Freshwater salinization is receiving increasing global attention due to its profound influence on nitrogen cycling in aquatic ecosystems and the accessibility of water resources.However,a comprehensive understanding of the changes in river salinization and the impacts of salinity on nitrogen cycling in arid and semi-arid regions of China is currently lacking.A meta-analysis was first conducted based on previous investigations and found an intensification in river salinization that altered hydrochemical characteristics.To further analyze the impact of salinity on nitrogen metabolism processes,we evaluated rivers with long-term salinity gradients based on in situ observations.The genes and enzymes that were inhibited generally by salinity,especially those involved in nitrogen fixation and nitrification,showed low abundances in three salinity levels.The abundance of genes and enzymes with denitrification and dissimilatory nitrate reduction to ammonium functions still maintained a high proportion,especially for denitrification genes/enzymes that were enriched under medium salinity.Denitrifying bacteria exhibited various relationships with salinity,while dissimilatory nitrate reduction to ammonium bacterium(such as Hydrogenophaga and Curvibacter carrying nirB)were more inhibited by salinity,indicating that diverse denitrifying bacteria could be used to regulate nitrogen concentration.Most genera exhibited symbiotic and mutual relationships,and the highest proportion of significant positive correlations of abundant genera was found under medium salinity.This study emphasizes the role of river salinity on environment characteristics and nitrogen transformation rules,and our results are useful for improving the availability of river water resources in arid and semi-arid regions.展开更多
文摘In order to implement industrial production of selected functional bacteria for bioremediation of shrimp culture environment, the fermentation conditions of the three functional bacteria, which have high ability in degrading organic pollutants at the bottom of shrimp ponds, were studied. The results showed that the favorable fermentation medium （per L） was 25 g of peptone, 5 g of yeast extract, and 0.2 g of ferric phosphate, and the initial pH value of the medium was 8.0. The optimum fermentation time was 20 h. The optimum stirring way was stirring one hour after one hour. Iso-electric point sedimentation collecting method was the most efficient and economic method to collect the bacteria cells after fermentation, with the optimum sediment pH of 3.67, 4.02, and 3.40 for the strains Lt7222, Gy7018 and Lt7511,respectively. It was also indicated that the survival and reproducing ability of the bacterial cells were not affected by the sedimentation process.
基金The paper is supported by the national high-technology development project (819-02-07) and the project of NSFC (30200209).
文摘After the single-strain abilities of organic-pollutant-degrading bacteria in bioremediation of sediment environment of shrimp culture are determined, the multi- strain degrading effect of the compositions of different strains is measured. The results indicate that the multi-strains groups have higher degrading ability than the single -strain groups. Three-strain groups are better than two-strain groups, and four-strain groups are better than three-strain groups and five-strain groups, the groups composed of strains Lt7222, Lt7511, Fc6308 and Gy7018 has the best degrading effect, the CODMn removal rate is 73.2 % in 66 h, and gets to 82.7 % in 114 h, 30 % higher than that of the best single-strain group; Groups of Lt7222, Lt7511, Lt7451 and Gy7018 are the second, whose CODMn removal rate is 82.1 % in 114 h. It is suggested that multi-species bacteria be used as functional bacteria in bioremediation of mariculture environment.
文摘Fecal microbiota transplantation(FMT),also known as fecal bacterial therapy,is a treatment option that can quickly reconstruct the normal composition of intestinal microbes,and it has a good therapeutic effect on Clostridium difficile infection,as well as on other microecological disorders.However,the causal mechanism of FMT efficacy remains to be clarified,its safety is a major problem,and the standardization and acceptability of FMT need to be improved.This review summarizes its current research status and potential research areas that need to be strengthened,and proposes to clarify the safety of FMT and the causal relationship between FMT and therapeutic effectiveness based on germ-free animals.Meanwhile,the research system is combined with multiomics technology to screen the effective bacteria in FMT,and develop standard,safe,effective and controllable flora of FMT.
基金the National Natural Science Foundation of China(31160122)the Key Laboratory of Grassland Ecosystem(Gansu Agricultural University),Ministry of Education(CYzs-2011011)for financial support
文摘A total of 50 endophytic bacterial isolates were obtained from Kobreasia capillifolia at alpine grasslands in the Eastern Qilian Mountains on the Tibetan Plateau in China. Based on the sequencing and phylogenetic analysis of 16 S r DNA genes, all isolates phylogenetically related closely to Bacillus, Acinetobacter, Stenotrophomonas, Brevundimonas, Arthrobacter, Curtobacterium, Paenibacillus, Plantibacter, Promicromonospora, Serratia, and Microbacterium, among which Bacillus was the predominant genus（47.8% of the total number of endophytic isolates）. These isolates possessed different biological functions. In 50 endophytic bacteria, 42 isolates produced indole acetic acid（IAA） on King medium. There were seven isolates showing potency of mineral phosphate solubilization in Pikovaskaia＇s（PKO） liquid medium. Seven isolates exhibited antagonistic effect against Fusarium avenaceum, Colletotrichum coccodes and Phoma foveata. This was the first report on diversity and plant growth promotion of endophytic bacteria from K. capillifolia on alpine grassland in the Eastern Qilian Mountains, Chain. It is essential for revealing the relationship among plant, microorganism, and the special environment because the potential function of endophytic bacteria made a contribution to the interactions of plants and endophytic bacteria.
基金supported by the National Natural Science Foundation of China(Nos.51838013,51808536)the National Key R&D Program of China(No.2016YFC0400804)
文摘Small diameter gravity sewers(SDGS)are extensively used to collect rural sewage as they are low in cost and quick to construct.However,the characteristics of biofilms in rural SDGS are still not clear.In this study,biofilms characteristics of aerobic rural SDGS were investigated using simulations in a lab under different flow conditions and slopes.Results indic ated that the average thickness of aerobic rural SDGS biofilms was in the range of 350-650μm,decreasing at locations with variable flow and high slopes.Protein was the most abundant substance in extracellular polymeric substance of SDGS biofilms.The most abundant bacteria,Proteobacteria,Actinobacteria,and Bacteroidetes,and functional bacteria showed different distributions when analyzed through Illumina HiSeq sequencing of 16 S rRNA.The relative abundances of denitrifying bacteria,nitrite-oxidizing bacteria,and sulfate-reducing bacteria(SRB)were lower during variable flow than during stable flow.High slopes(15‰)decreased SRB presence,which could be used to mitigate H2 S accumulation in aerobic SDGS.Overall,this study describes the characteristics of aerobic rural SDGS biofilms and provides valuable suggestions for the optimal design of SDGS based on these characteristics.
基金the National Key R&D Program of China(No.2017YFE0114300)National Natural Science Foundation of China(Nos.32161143031,51622813 and 51878675).
文摘Understanding the structures and dynamics of bacterial communities in activated sludge(AS)in full-scale wastewater treatment plants(WWTPs)is of both engineering and ecological significance.Previous investigations have mainly focused on the AS communities of WWTP aeration tanks,and the differences and interactions between the communities in anaerobic and anoxic tanks of the AS system remain poorly understood.Here,we investigated the structures of bacterial communities and their inter-connections in three tanks(anaerobic,anoxic,and aerobic)and influent from a full-scale WWTP with conventional anaerobic/anoxic/aerobic(A/A/O)process over a year to explore their functionality and network differentiation.High-throughput sequencing showed that community compositions did not differ appreciably between the different tanks,likely due to the continuous sludge community interchange between tanks.However,network analysis showed significant differences in inter-species relationships,OTU topological roles,and keystone populations in the different AS communities.Moreover,the anoxic network is expected to be more unstable and easily affected by environmental disturbance.Tank-associated environmental factors,including dissolved oxygen,pH,and nutrients,were found to affect the relative abundance of functional genera(i.e.,AOB,NOB,PAOs,and denitrifiers),suggesting that these groups were more susceptible to environmental variables than other bacteria.Therefore,this work could assist in improving our understanding of tank-associated microbial ecology,particularly the response of functional bacteria to seasonal variations in WWTPs employing A/A/O process.
基金This work was supported by grants from National Key Research and Development Program of China(2017YFD0200604)Key Research Program of Frontier Sciences,CAS(ZDBS-LYDQC017)+5 种基金the National Natural Science Foundation of China(41671251)Earmarked Fund for China Agriculture Research System(CR34)Heilongjiang Provincial Natural Science Foundation of China(D2018009)the Grass-field Rotation Scientist Studio of Heilongjiang Province(202004)Outstanding Youth Fund of Heilongjiang Academy of Agricultural Sciences(2020JCQN003)Youth Innovation Promotion Association,CAS(2017276).
文摘Alfalfa is a perennial herbaceous forage legume that is remarkably and negatively affected by monocropping.However,the contribution of the changes in bacterial communities to soil sickness in alfalfa have not been elucidated.Therefore,we investigated bacterial community structures in response to monocropped alfalfa along the chronosequence.Continuous cropping remarkably reduced bacterial alpha diversity and altered community structures,and soil pH,total P and available P were strongly associated with the changes of bacterial diversity and community structures.Intriguingly,10 years of monocropped alfalfa might be a demarcation point separating soil bacterial community structures into two obvious groups that containing soil samples collected in less and more than 10 years.The relative abundances of copiotrophic bacteria of Actinobacteria and Gammaproteobacteria significantly increased with the extension of continuous cropping years,while the oligotrophic bacteria of Armatimonadetes,Chloroflexi,Firmicutes and Gemmatimonadetes showed the opposite changing patterns.Among those altered phyla,Actinobacteria,Chloroflexi,Alphaproteobacteria and Acidobacteria were the most important bacteria which contributed 50.86%of the community variations. Additionally, the relative abundances of nitrogen fixation bacteria ofBradyrhizobium and Mesorhizobium obviously increased with continuous cropping years, while theabundances of Arthrobacter, Bacillus, Burkholderiaceae and Microbacterium with potential functionsof solubilizing phosphorus and potassium remarkably decreased after long-term continuouscropping. Furthermore, bacterial cooccurrence patterns were significantly influenced by continuouscropping years, with long-term monocropped alfalfa simplifying the complexity of the cooccurrencenetworks. These findings enhanced our understandings and provided references for forecasting howsoil bacterial communities responds to monocropped alfalfa.
基金supported by the Innovative team project of Nanjing Institute of Environmental Sciences,MEE(GYZX200101)the National Natural Science Foundation of China(52270160,and U23A2058)+1 种基金the Key R&D Program of Ningxia Hui Autonomous Region(2021BEG01002)the Xinjiang UygurAutonomous Region Science and Technology ProgramPlan(2022E02026)the SuperG project of EUHorizon 2020 program(774124).
文摘Freshwater salinization is receiving increasing global attention due to its profound influence on nitrogen cycling in aquatic ecosystems and the accessibility of water resources.However,a comprehensive understanding of the changes in river salinization and the impacts of salinity on nitrogen cycling in arid and semi-arid regions of China is currently lacking.A meta-analysis was first conducted based on previous investigations and found an intensification in river salinization that altered hydrochemical characteristics.To further analyze the impact of salinity on nitrogen metabolism processes,we evaluated rivers with long-term salinity gradients based on in situ observations.The genes and enzymes that were inhibited generally by salinity,especially those involved in nitrogen fixation and nitrification,showed low abundances in three salinity levels.The abundance of genes and enzymes with denitrification and dissimilatory nitrate reduction to ammonium functions still maintained a high proportion,especially for denitrification genes/enzymes that were enriched under medium salinity.Denitrifying bacteria exhibited various relationships with salinity,while dissimilatory nitrate reduction to ammonium bacterium(such as Hydrogenophaga and Curvibacter carrying nirB)were more inhibited by salinity,indicating that diverse denitrifying bacteria could be used to regulate nitrogen concentration.Most genera exhibited symbiotic and mutual relationships,and the highest proportion of significant positive correlations of abundant genera was found under medium salinity.This study emphasizes the role of river salinity on environment characteristics and nitrogen transformation rules,and our results are useful for improving the availability of river water resources in arid and semi-arid regions.
