Microalgal-indigenous bacterial wastewater treatment(MBWT)emerges as a promising approach for the concurrent removal of nitrogen(N)and phosphorus(P).Despite its potential,the prevalent use of MBWT in batch systems lim...Microalgal-indigenous bacterial wastewater treatment(MBWT)emerges as a promising approach for the concurrent removal of nitrogen(N)and phosphorus(P).Despite its potential,the prevalent use of MBWT in batch systems limits its broader application.Furthermore,the success of MBWT critically depends on the stable self-adaptation and synergistic interactions between microalgae and indigenous bacteria,yet the underlying biological mechanisms are not fully understood.Here we explore the viability and microbial dynamics of a continuous flow microalgae-indigenous bacteria advanced wastewater treatment system(CFMBAWTS)in processing actual secondary effluent,with a focus on varying hydraulic retention times(HRTs).The research highlights a stable,mutually beneficial relationship between indigenous bacteria and microalgae.Microalgae and indigenous bacteria can create an optimal environment for each other by providing essential cofactors(like iron,vitamins,and indole-3-acetic acid),oxygen,dissolved organic matter,and tryptophan.This collaboration leads to effective microbial growth,enhanced N and P removal,and energy generation.The study also uncovers crucial metabolic pathways,functional genes,and patterns of microbial succession.Significantly,the effluent NH4 t-N and P levels complied with the Chinese national Class-II,Class-V,Class-IA,and Class-IB wastewater discharge standards when the HRT was reduced from 15 to 6 h.Optimal results,including the highest rates of CO_(2)fixation(1.23 g L^(-1)),total energy yield(32.35 kJ L^(-1)),and the maximal lipid(33.91%)and carbohydrate(41.91%)content,were observed at an HRT of 15 h.Overall,this study not only confirms the feasibility of CFMBAWTS but also lays a crucial foundation for enhancing our understanding of this technology and propelling its practical application in wastewater treatment plants.展开更多
Variations of precipitation have great impacts on soil carbon cycle and decomposition of soil organic matter.Soil bacteria are crucial participants in regulating these ecological processes and vulnerable to altered pr...Variations of precipitation have great impacts on soil carbon cycle and decomposition of soil organic matter.Soil bacteria are crucial participants in regulating these ecological processes and vulnerable to altered precipitation.Studying the impacts of altered precipitation on soil bacterial community structure can provide a novel insight into the potential impacts of altered precipitation on soil carbon cycle and carbon storage of grassland.Therefore,soil bacterial community structure under a precipitation manipulation experiment was researched in a semi-arid desert grassland in Chinese Loess Plateau.Five precipitation levels,i.e.,control,reduced and increased precipitation by 40%and 20%,respectively(referred here as CK,DP40,DP20,IP40,and IP20)were set.The results showed that soil bacterial alpha diversity and rare bacteria significantly changed with altered precipitation,but the dominant bacteria and soil bacterial beta diversity did not change,which may be ascribed to the ecological strategy of soil bacteria.The linear discriminate analysis(LDA)effect size(LEfSe)method found that major response patterns of soil bacteria to altered precipitation were resource-limited and drought-tolerant populations.In addition,increasing precipitation greatly promoted inter-species competition,while decreasing precipitation highly facilitated inter-species cooperation.These changes in species interaction can promote different distribution ratios of bacterial populations under different precipitation conditions.In structural equation model(SEM)analysis,with changes in precipitation,plant growth characteristics were found to be drivers of soil bacterial community composition,while soil properties were not.In conclusion,our results indicated that in desert grassland ecosystem,the sensitive of soil rare bacteria to altered precipitation was stronger than that of dominant taxa,which may be related to the ecological strategy of bacteria,species interaction,and precipitation-induced variations of plant growth characteristics.展开更多
Understanding interspecies interactions is essential to predict the response of microbial communities to exogenous perturbation.Herein,rhizospheric and bulk soils were collected from five developmental stages of soybe...Understanding interspecies interactions is essential to predict the response of microbial communities to exogenous perturbation.Herein,rhizospheric and bulk soils were collected from five developmental stages of soybean,which grew in soils receiving 16-year nitrogen inputs.Bacterial communities and functional profiles were examined using high-throughput sequencing and quantitative PCR,respectively.The objective of this study was to identify the key bacterial interactions that influenced community dynamics and functions.We found that the stages of soybean development outcompeted nitrogen fertilization management in shaping bacterial community structure,while fertilization treatments significantly shaped the abundance distribution of nitrogen functional genes.Temporal variations in bacterial abundances increased in bulk soils,especially at the stage of soybean branching,which helps to infer underlying negative interspecies interactions.Members of Cyanobacteria and Actinobacteria actively engaged in inter-phylum negative interactions in bulk soils and soybean rhizosphere,respectively.Furthermore,the negative interactions between nitrogen-fixing functional groups and the reduction of nifH gene abundance were coupled during soybean development,which may help to explain the linkages between population dynamics and functions.Overall,these findings highlight the importance of inter-phylum negative interactions in shaping the correlation patterns of bacterial communities and in determining soil functional potential.展开更多
To alleviate soil phosphorus deficiency,integrating straw-derived biochar with phosphate-solubilizing bacteria(PSB)has been recognized as a promising solution and is gaining growing attention.However,the mechanisms of...To alleviate soil phosphorus deficiency,integrating straw-derived biochar with phosphate-solubilizing bacteria(PSB)has been recognized as a promising solution and is gaining growing attention.However,the mechanisms of bacterial immobilization and the influences of the physicochemical attributes of biochar remain unclear.In this study,we investigated the single-cell interactions of gram-negative Acinetobacter pittii and gram-positive Bacillus subtilis with cotton straw-derived biochars,subjected to progressively increasing pyrolysis temperatures,to understand the attributes of gradually modified biochar properties.The results revealed the correlations between adhesion forces and biochar properties(e.g.,surface area and surface charge),and the strongest adhesion for both strains for the biochar pyrolyzed at 700℃.The extended Derjaguin-Landau-Verwey-Overbeek(XDLVO)model,structured to predict interaction energy,was subsequently compared with experimental observations made using atomic force microscopy(AFM).Discrepancies between the predicted high adhesion barriers and the observed attraction suggested that forces beyond Lifshitz-van der Waals also influenced the immobilization of PSB.Adhesion-distance spectroscopy and XDLVO theory jointly revealed four distinct phases in the immobilization process by biochar:planktonic interaction,secondary minimum entrapment,primary barrier transcendence,and initial reversible adherence,collectively facilitating biofilm formation.Notably,initial reversible adhesion positively correlated with increased protein and polysaccharide levels in extracellular polymeric substances(EPS)(R^(2)>0.67),highlighting its importance in biofilm formation.Unraveling PSB–biochar interactions can improve the effectiveness of soil inoculants,thereby enhancing phosphorus availability in soil,a crucial factor for promoting plant growth and supporting environmental sustainability.展开更多
Bacteria pretend to organize into complex,multicellular structures known as biofilms,which enable survival and adaptation in dynamic environments.Bacterial biofilms serve diverse functions,including providing structur...Bacteria pretend to organize into complex,multicellular structures known as biofilms,which enable survival and adaptation in dynamic environments.Bacterial biofilms serve diverse functions,including providing structural stability,directing metabolic adaptations,and facilitating bacterial expansion and nutrient acquisition.In natural environments,biofilms are predominantly formed by diverse multispecies bacteria.The formation of multispecies biofilms is a dynamic process shaped by intricate bacterial interactions,encompassing both cooperative and antagonistic behaviors.These interactions are mediated by signaling molecules that facilitate cell-to-cell communications,influenced by the spatiotemporal heterogeneity of the extracellular polymeric substance matrix and biofilm architecture.This review synthesizes recent advances in understanding bacterial interactions within biofilms,focusing on mediating metabolites,underlying mechanisms,and their implications for the process of biofilm development.These insights offer a foundation for developing strategies to manipulate microbial communities and control biofilm-related challenges.展开更多
Microbial cross-feedings hold great significance for microbial survival and growth,which are commonly considered to be determined by functional complementarity.Here we demonstrated landform-dependent cross-feedings be...Microbial cross-feedings hold great significance for microbial survival and growth,which are commonly considered to be determined by functional complementarity.Here we demonstrated landform-dependent cross-feedings between comammox Nitrospira for complete ammonia oxidizing and symbiotic bacteria in the Yangtze River.Although 2 metabolites between co-mammox Nitrospira and symbiotic bacteria were inferred by functional complementarity,a total of 71 metabolites were ex-changed indicated by the newly developed flux balance analysis and optimization algorithm.Comammox Nitrospira served as an amino acid donor in plain regions,but functioned as an amino acid recipient in mountain-foothill regions by modifying cross-feeding modes to adapt to harsh conditions.Large grain sizes in mountain-foothill regions help microbial aggrega-tion.This process benefits comammox Nitrospira with metabolic deficiencies to absorb metabolites from others,to increase their survival capacity.This study highlights the important role of cross-feedings in the microbial community assembly and nitrogen cycling in the Yangtze River.展开更多
基金supported by the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.2022TS13)the National Key Research and Development Program(No.2019YFC0408503)the Key Research Program of Wuhan(No.2022022202015015).
文摘Microalgal-indigenous bacterial wastewater treatment(MBWT)emerges as a promising approach for the concurrent removal of nitrogen(N)and phosphorus(P).Despite its potential,the prevalent use of MBWT in batch systems limits its broader application.Furthermore,the success of MBWT critically depends on the stable self-adaptation and synergistic interactions between microalgae and indigenous bacteria,yet the underlying biological mechanisms are not fully understood.Here we explore the viability and microbial dynamics of a continuous flow microalgae-indigenous bacteria advanced wastewater treatment system(CFMBAWTS)in processing actual secondary effluent,with a focus on varying hydraulic retention times(HRTs).The research highlights a stable,mutually beneficial relationship between indigenous bacteria and microalgae.Microalgae and indigenous bacteria can create an optimal environment for each other by providing essential cofactors(like iron,vitamins,and indole-3-acetic acid),oxygen,dissolved organic matter,and tryptophan.This collaboration leads to effective microbial growth,enhanced N and P removal,and energy generation.The study also uncovers crucial metabolic pathways,functional genes,and patterns of microbial succession.Significantly,the effluent NH4 t-N and P levels complied with the Chinese national Class-II,Class-V,Class-IA,and Class-IB wastewater discharge standards when the HRT was reduced from 15 to 6 h.Optimal results,including the highest rates of CO_(2)fixation(1.23 g L^(-1)),total energy yield(32.35 kJ L^(-1)),and the maximal lipid(33.91%)and carbohydrate(41.91%)content,were observed at an HRT of 15 h.Overall,this study not only confirms the feasibility of CFMBAWTS but also lays a crucial foundation for enhancing our understanding of this technology and propelling its practical application in wastewater treatment plants.
基金supported by the National Natural Science Foundation of China (41761043, 41201196)the Youth Teacher Scientific Capability Promoting Project of Northwest Normal University, China (NWNU-LKQN2020-06, NWNU-LKQN-17-7)the Key Research and Development Program of Gansu Province, China (20YF3FA042)
文摘Variations of precipitation have great impacts on soil carbon cycle and decomposition of soil organic matter.Soil bacteria are crucial participants in regulating these ecological processes and vulnerable to altered precipitation.Studying the impacts of altered precipitation on soil bacterial community structure can provide a novel insight into the potential impacts of altered precipitation on soil carbon cycle and carbon storage of grassland.Therefore,soil bacterial community structure under a precipitation manipulation experiment was researched in a semi-arid desert grassland in Chinese Loess Plateau.Five precipitation levels,i.e.,control,reduced and increased precipitation by 40%and 20%,respectively(referred here as CK,DP40,DP20,IP40,and IP20)were set.The results showed that soil bacterial alpha diversity and rare bacteria significantly changed with altered precipitation,but the dominant bacteria and soil bacterial beta diversity did not change,which may be ascribed to the ecological strategy of soil bacteria.The linear discriminate analysis(LDA)effect size(LEfSe)method found that major response patterns of soil bacteria to altered precipitation were resource-limited and drought-tolerant populations.In addition,increasing precipitation greatly promoted inter-species competition,while decreasing precipitation highly facilitated inter-species cooperation.These changes in species interaction can promote different distribution ratios of bacterial populations under different precipitation conditions.In structural equation model(SEM)analysis,with changes in precipitation,plant growth characteristics were found to be drivers of soil bacterial community composition,while soil properties were not.In conclusion,our results indicated that in desert grassland ecosystem,the sensitive of soil rare bacteria to altered precipitation was stronger than that of dominant taxa,which may be related to the ecological strategy of bacteria,species interaction,and precipitation-induced variations of plant growth characteristics.
基金supported by the National Natural Science Foundation of China[41830755,41701291,and 42077049].
文摘Understanding interspecies interactions is essential to predict the response of microbial communities to exogenous perturbation.Herein,rhizospheric and bulk soils were collected from five developmental stages of soybean,which grew in soils receiving 16-year nitrogen inputs.Bacterial communities and functional profiles were examined using high-throughput sequencing and quantitative PCR,respectively.The objective of this study was to identify the key bacterial interactions that influenced community dynamics and functions.We found that the stages of soybean development outcompeted nitrogen fertilization management in shaping bacterial community structure,while fertilization treatments significantly shaped the abundance distribution of nitrogen functional genes.Temporal variations in bacterial abundances increased in bulk soils,especially at the stage of soybean branching,which helps to infer underlying negative interspecies interactions.Members of Cyanobacteria and Actinobacteria actively engaged in inter-phylum negative interactions in bulk soils and soybean rhizosphere,respectively.Furthermore,the negative interactions between nitrogen-fixing functional groups and the reduction of nifH gene abundance were coupled during soybean development,which may help to explain the linkages between population dynamics and functions.Overall,these findings highlight the importance of inter-phylum negative interactions in shaping the correlation patterns of bacterial communities and in determining soil functional potential.
基金supported by the National Natural Science Foundation of China(Grant No.52200198)Taishan Scholars Project of Shandong Province(NO.tstp20230604)Natural Science Foundation of Shandong Province(Grant No.ZR2021QB186).
文摘To alleviate soil phosphorus deficiency,integrating straw-derived biochar with phosphate-solubilizing bacteria(PSB)has been recognized as a promising solution and is gaining growing attention.However,the mechanisms of bacterial immobilization and the influences of the physicochemical attributes of biochar remain unclear.In this study,we investigated the single-cell interactions of gram-negative Acinetobacter pittii and gram-positive Bacillus subtilis with cotton straw-derived biochars,subjected to progressively increasing pyrolysis temperatures,to understand the attributes of gradually modified biochar properties.The results revealed the correlations between adhesion forces and biochar properties(e.g.,surface area and surface charge),and the strongest adhesion for both strains for the biochar pyrolyzed at 700℃.The extended Derjaguin-Landau-Verwey-Overbeek(XDLVO)model,structured to predict interaction energy,was subsequently compared with experimental observations made using atomic force microscopy(AFM).Discrepancies between the predicted high adhesion barriers and the observed attraction suggested that forces beyond Lifshitz-van der Waals also influenced the immobilization of PSB.Adhesion-distance spectroscopy and XDLVO theory jointly revealed four distinct phases in the immobilization process by biochar:planktonic interaction,secondary minimum entrapment,primary barrier transcendence,and initial reversible adherence,collectively facilitating biofilm formation.Notably,initial reversible adhesion positively correlated with increased protein and polysaccharide levels in extracellular polymeric substances(EPS)(R^(2)>0.67),highlighting its importance in biofilm formation.Unraveling PSB–biochar interactions can improve the effectiveness of soil inoculants,thereby enhancing phosphorus availability in soil,a crucial factor for promoting plant growth and supporting environmental sustainability.
基金supported by the Natural Science Foundation of Zhejiang Province,China(No.ZCLTGN24C2001).
文摘Bacteria pretend to organize into complex,multicellular structures known as biofilms,which enable survival and adaptation in dynamic environments.Bacterial biofilms serve diverse functions,including providing structural stability,directing metabolic adaptations,and facilitating bacterial expansion and nutrient acquisition.In natural environments,biofilms are predominantly formed by diverse multispecies bacteria.The formation of multispecies biofilms is a dynamic process shaped by intricate bacterial interactions,encompassing both cooperative and antagonistic behaviors.These interactions are mediated by signaling molecules that facilitate cell-to-cell communications,influenced by the spatiotemporal heterogeneity of the extracellular polymeric substance matrix and biofilm architecture.This review synthesizes recent advances in understanding bacterial interactions within biofilms,focusing on mediating metabolites,underlying mechanisms,and their implications for the process of biofilm development.These insights offer a foundation for developing strategies to manipulate microbial communities and control biofilm-related challenges.
文摘Microbial cross-feedings hold great significance for microbial survival and growth,which are commonly considered to be determined by functional complementarity.Here we demonstrated landform-dependent cross-feedings between comammox Nitrospira for complete ammonia oxidizing and symbiotic bacteria in the Yangtze River.Although 2 metabolites between co-mammox Nitrospira and symbiotic bacteria were inferred by functional complementarity,a total of 71 metabolites were ex-changed indicated by the newly developed flux balance analysis and optimization algorithm.Comammox Nitrospira served as an amino acid donor in plain regions,but functioned as an amino acid recipient in mountain-foothill regions by modifying cross-feeding modes to adapt to harsh conditions.Large grain sizes in mountain-foothill regions help microbial aggrega-tion.This process benefits comammox Nitrospira with metabolic deficiencies to absorb metabolites from others,to increase their survival capacity.This study highlights the important role of cross-feedings in the microbial community assembly and nitrogen cycling in the Yangtze River.
