Background The enteric methane inhibitor 3-nitrooxypropanol(3-NOP)inhibits the key enzyme in ruminal methanogenesis,but whether short-term(ST)and long-term(LT)dietary supplementation has similar effects on rumen micro...Background The enteric methane inhibitor 3-nitrooxypropanol(3-NOP)inhibits the key enzyme in ruminal methanogenesis,but whether short-term(ST)and long-term(LT)dietary supplementation has similar effects on rumen microbiota in beef cattle and how microbes change after 3-NOP withdrawal have not been studied.This study investigated changes in rumen bacteria,archaea,and protozoa after ST and LT dietary supplementation and removal of 3-NOP using metataxonomic analysis.Results A total of 143 rumen samples were collected from two beef cattle studies with 3-NOP supplementation.The ST study(95 samples)used eight ruminally cannulated beef cattle in a 4×4 Latin square design with four 28-d of 3-NOP treatments[mg/kg of dry matter(DM)]:control:0,low:53,med:161,and high:345.The LT study(48 samples)was a completely randomized design with two 3-NOP treatments[control:0,and high:280 mg/kg of DM)fed for 112-d followed by a 16-d withdrawal(without 3-NOP).Bacterial and archaeal communities were significantly affected by 3-NOP supplementation but limited effects on protozoal communities were observed.Under ST supplementation,the relative abundances of Prevotella,Methanobrevibacter(Mbb.)ruminantium,Methanosphaera sp.ISO3-F5,and Entodinium were increased(Q<0.05),whereas those of Mbb.gottschalkii and Epidinium were decreased(Q<0.05)with 3-NOP supplementation.In LT study,relative abundances of Mbb.ruminantium,and Methanosphaera sp.Group5 were increased(Q<0.05),while those of Saccharofermentans and Mbb.gottschalkii were decreased(Q<0.05)with 3-NOP supplementation.Comparison between 3-NOP supplementation and the withdrawal revealed increased relative abundances of Clostridia UCG-014 and Oscillospiraceae NK4A214 group and decreased those of Eubacterium nodatum group and Methanosphaera sp.Group5(P<0.05)after 3-NOP withdrawal.Further comparison of rumen microbiota between control and 3-NOP withdrawal showed significantly higher(P=0.029)relative abundances of Eggerthellaceae DNF00809,p-1088-a5 gut group,and Family XII UCG-001 in control group while no significant differences were detected for archaea and protozoa.Microbial network analysis revealed that microbial interactions differed by both 3-NOP dose and durations.Conclusions Both ST and LT supplementation affected overall rumen microbial profile,with individual microbial groups responded to 3-NOP supplementation differently.After 3-NOP withdrawal,not all microbes showed recovery,indicating that the 3-NOP driven shifts were only partially reversible.These findings provide an understanding of the effects of 3-NOP on rumen microbial communities and their adaptability to methane mitigation strategies.展开更多
The formation of Mesozoic natural gas in the Pengyang area of southwestern Ordos Basin is discussed,from the perspective of microbial community characteristics,in order to clarify the relationship between the origin o...The formation of Mesozoic natural gas in the Pengyang area of southwestern Ordos Basin is discussed,from the perspective of microbial community characteristics,in order to clarify the relationship between the origin of natural gas and its associated indigenous microbial community.The types and diversity of indigenous microbial communities associated with the oil reservoir were studied by means of collecting reservoir formation water samples from exploration wells.The indigenous microbial communities in the Chang 8 member of the Yanchang Formation were primarily distributed within Proteobacteria and Firmicutes,including the specific species and genera of Methylobacter,Pseudomonas,Haibacter,Toxobacillus,Acinetobacter and Adura actinomyces.The results of diversity analysis shows that the number of common genes was 5448,while the number of unique genes and information was less.This reflects the fact that the strata in the study area are relatively closed and not invaded by external water sources,which leads to the development of biological community diversity.In conjunction with the analysis of geochemical characteristics of oil and gas reservoirs in this area,this indicates that the study area possesses the necessary geological conditions for microbial degradation.It is the first time that the species and diversity of the indigenous microbial community in the Ordos Basin have been analyzed,showing that microbial degradation is the main cause of natural gas formation here,changes the characteristics of crude oil in this area and provides first-hand information on the impact of indigenous microorganisms on the reservoir.展开更多
In this study,the effects of different salinity gradients and addition of compatible solutes on anaerobic treated effluent water qualities,sludge characteristics and microbial communities were investigated.The increas...In this study,the effects of different salinity gradients and addition of compatible solutes on anaerobic treated effluent water qualities,sludge characteristics and microbial communities were investigated.The increase in salinity resulted in a decrease in particle size of the granular sludge,which was concentrated in the range of 0.5-1.0 mm.The content of EPS(extracellular polymeric substances)in the granular sludge gradually increased with increasing salinity and the addition of betaine(a typical compatible solute).Meanwhile,the microbial community structure was significantly affected by salinity,with high salinity reducing the diversity of bacteria.At higher salinity,Patescibacteria and Proteobacteria gradually became the dominant phylum,with relative abundance increasing to 13.53%and 12.16%at 20 g/L salinity.Desulfobacterota and its subordinate Desulfovibrio,which secrete EPS in large quantities,dominated significantly after betaine addition.Their relative abundance reached 13.65%and 7.86%at phylum level and genus level.The effect of these changes on the treated effluent was shown as the average chemical oxygen demand(COD)removal rate decreased from 82.10%to 79.71%,78.01%,68.51%and 64.55%when the salinity gradually increased from 2 g/L to 6,10,16 and 20 g/L.At the salinity of 20 g/L,average COD removal increased to 71.65%by the addition of 2 mmol/L betaine.The gradient elevated salinity and the exogenous addition of betaine played an important role in achieving stability of the anaerobic system in a highly saline environment,which provided a feasible strategy for anaerobic treatment of organic saline wastewater.展开更多
The large-scale exploitation of vanadium(Ⅴ) bearing minerals has led to a massive accumulation of Ⅴ tailings, of which Ⅴ pollution poses severe ecological risks. Although the mechanisms of Ⅴ stress to the microbia...The large-scale exploitation of vanadium(Ⅴ) bearing minerals has led to a massive accumulation of Ⅴ tailings, of which Ⅴ pollution poses severe ecological risks. Although the mechanisms of Ⅴ stress to the microbial community have been reported, the influential pathways in a multi-medium-containing system, for example, the soil-tailings-groundwater system,are unknown. The dynamic redox conditions and substance exchange within the system exhibited complex Ⅴ stress on the local microbial communities. In this study, the influence pathways of Ⅴ stress to the microbial community in the soil-tailings-groundwater system were first investigated. High Ⅴ contents were observed in groundwater(139.2 ± 0.15 μg/L) and soil(98.0–323.8 ± 0.02 mg/kg), respectively. Distinct microbial composition was observed for soil and groundwater, where soil showed the highest level of diversity and richness. Firmicutes, Proteobacteria, Actinobacteria, and Acidobacteria were dominant in soil and groundwater with a sum relative abundance of around 80 %. Based on redundancy analysis and structural equation models, Ⅴ was one of the vital driving factors affecting microbial communities. Groundwater microbial communities were influenced by Ⅴ via Cr, dissolved oxygen, and total nitrogen, while Fe, Mn, and total phosphorus were the key mediators for Ⅴ to affect soil microbial communities. Ⅴ affected the microbial community via metabolic pathways related to carbonaceous matter, which was involved in the establishment of survival strategies for metal stress. This study provides novel insights into the influence pathways of Ⅴ on the microorganisms in tailings reservoir for pollution bioremediation.展开更多
Microalgae-bacteria system is an emerging alternative for sustainable wastewater treatment.Exploring the structure and diversity of microbial community in microalgae-bacteria system under sulfadiazine stress can contr...Microalgae-bacteria system is an emerging alternative for sustainable wastewater treatment.Exploring the structure and diversity of microbial community in microalgae-bacteria system under sulfadiazine stress can contribute to the understanding of the sulfadiazine behavior in environments.Furthermore,as important carriers of antibiotic resistance genes(ARGs),microalgae can influence the profiles of ARGs either directly or indirectly through the secretion of metabolites.However,the effects of sulfadiazine on ARGs dissemination of microalgae-bacteria systems remain underreported.Herein,the impacts of sulfadiazine(1 mg/L)on the structural diversity and metabolic activity of microorganisms were examined in microalgae-bacteria systems.Results showed thatmicroalgae-bacteria system could remove NH_(4)^(+)-N better(about 72.3%)than activated sludge system,and hydrolysis was the first step in sulfadiazine degradation.A high level of intI1(5.7×10^(4) copies/mL)was detected in the initial media of the microalgae-bacteria system.Microalgae could hamper the rate of horizontal gene transfer activation.Compared with activated sludge system,the abundance of sul genes(sul1,sul2,sul3,and sulA)was significantly lowered after treating with microalgae-bacteria system.Additionally,the number of proteins and the sum of polysaccharides in the extracellular polymeric substances of the activated sludge system were lower than those of themicroalgae-bacteria system.Microalgae can altermicrobial communities.The genus Rozellomycota predominated all samples.Fungi with relatively high abundance increased in the microalgae-bacteria system,including Dipodascaceae,Rhodotorula,and Geotrichum.These results offer valuable insights into the application processes involving microalgae-bacteria system.展开更多
The problem of soil polycyclic aromatic hydrocarbon(PAH)pollution in coking plant sites has been widely studied in recent years,but there is a lack of research on the correlation between soil microorganisms,soil metab...The problem of soil polycyclic aromatic hydrocarbon(PAH)pollution in coking plant sites has been widely studied in recent years,but there is a lack of research on the correlation between soil microorganisms,soil metabolomics,and soil properties.Thus,in this study,the long-term impact of coke combustion on soil microbial community structure,enzyme activities,and metabolic pathways within a former coking plant site was investigated.Soil samples were collected from both the coking production area(CA group)and office area(OLA group),approximately 0 to 20 cm in depth.Compared with OLA group,elevated levels of 16 PAHs in the list of US EPA were detected by gas chromatography-mass spectrometry in the CA group.Several dominant microorganisms,such as Altererythrobacter,Lysobacter,and Sulfurifustis,were identified by 16 s ribosomal DNA sequencing in the CA group.The fatty acid biosynthesis pathway exhibited specific inhibition,while the phenylalanine metabolic pathwaywas promoted in response to PAH stress.Long-term PAH exposure led to the inhibition of soil urease activity.The co-occurrence network ofmicroorganisms revealed intricate patterns of co-metabolism and co-adaptation within complex bacterial communities,facilitating their adaptation to and decomposition of soil-borne PAHs.This research could provide valuable insights into the community characteristics andmetabolic mechanisms of microorganisms inhabiting PAH-polluted soil within coking plant sites.The findings enhance our understanding of the indigenous soil microbiome and its intricate network dynamics under the persistent stress of PAHs,contributing to a more comprehensive knowledge of soil ecosystems in such environments.展开更多
The environmental impacts of acid mine drainage(AMD)from open-pit mining are profoundly detrimental,yet knowledge about its effects on paddy soil microbial communities,especially at greater depths,remains limited.In t...The environmental impacts of acid mine drainage(AMD)from open-pit mining are profoundly detrimental,yet knowledge about its effects on paddy soil microbial communities,especially at greater depths,remains limited.In this investigation,we compared soils affected by AMD versus unaffected soil depth profiles in terms of bacterial diversity and community assembly.The profiles in AMD-polluted soils exhibited tight geochemical gradients,characterized by increased acidity,SO_(4)^(2-),NO_(3)^(-),and heavy metal content compared to unpolluted soils.Notably,AMD significantly diminished soil bacterial biodiversity.A depthwise analysis showed distinct microbial stratification,with certain bacteria like Candidatus_Solibacter and Candidatus_Koribacter predominated in polluted soils,while others like Haliangium and Nitrospira were more prevalent in control soils.Interestingly,despite variable soil conditions,predictedmetabolic pathways,particularly those involving carbon,nitrogen,and sulfur,showed relative stability.AMD pollution induced the upregulation of methylcoenzyme M reductase and sulfate reductase genes.Bacterial communities were more responsive to pH and nutrient content rather than heavy metals,with pH and SO_(4)^(2-)being the primary drivers of microbial diversity and distribution.Additionally,pHwas identified as the most significant influence on the predicted methane,sulfur,and nitrogen metabolism.Furthermore,deterministic processes played a more significant role in community assembly of polluted soils,while heterogeneous selection gained importance with increasing depth in control soils.Additionally,microbial co-occurrences,particularly positive interactions,were more prevalent in the polluted soils with reduced network modularity and keystone taxa.These findings offer insights into sustaining microbial diversity in extreme environments.展开更多
Fermented chili products are popular traditional fermented foods around the world.However,differences in microbial communities in fermented chilies from different regions and how they affect the flavor compounds in ch...Fermented chili products are popular traditional fermented foods around the world.However,differences in microbial communities in fermented chilies from different regions and how they affect the flavor compounds in chili fermentation have not been reported.In this study,the dynamics of flavor compounds and microbial communities in fermented chilies from Sichuan,Guizhou,and Hunan were systematically investigated by macro-genome sequencing,solid phase microextraction-gas chromatograph-mass spectrometry(SPME-GC-MS),electronic nose,and electronic tongue techniques.Simultaneously,the microbial metabolic mechanisms and the relationship between flavor compounds and microbiome were unraveled through staged and simulated fermentation analysis.The results showed that 53 chemical odorants,including alcohols,esters,aldehydes,and acids,were identified as chemical markers to differentiate the regional samples.A total of 12 microbial species,including Staphylococcus xylosus,unclassified Staphylococcus species,Weissella confusus,Lactococcus cremoris,Lactococcus garvieae,Lactiplantibacillus sakei,Pediciococcus propionicigenes,Pediciococcus idahonensis,Pediciococcus aciditolerans,Nocardioides antri,Debaryomyces hansenii,and Colletotrichum scovillei,were identified as microbial markers to differentiate the regional samples.Correlation analysis showed that Lactobacillaceae was associated with fruity,floral,spicy,and fatty aromas.The electronic nose and tongue analysis results showed that 9 flavor and 8 taste indicators significantly differed between regional samples(P<0.05).Additionally,flavor compounds and microbial diversity were robust under initial selection stress and showed higher diversity under metabolome-microbiome interactions.Importantly,simulated fermentation confirmed that metabolome-microbiome interactions drove the shift in microbial structure,metabolism,and flavor in regionally fermented chilies.These results provide insights into the succession of microbial communities and the formation of flavor compounds in chili fermentation,which may enable the future replication of fermented foods with the same flavor.展开更多
The enhancement of chalcopyrite bioleaching with an enriched microbial community by acidified seawater was studied,and the enhancing mechanism was analyzed.The microbial community was enriched at the Dabaoshan mine si...The enhancement of chalcopyrite bioleaching with an enriched microbial community by acidified seawater was studied,and the enhancing mechanism was analyzed.The microbial community was enriched at the Dabaoshan mine site,and the treated ore sample had high concentrations of chalcopyrite and galena.The experimental results show that copper extraction from chalcopyrite with an enriched microbial community in seawater was promoted from 13.1%to 62.1%by acidification in comparison with that without acidification.Further analyses of the solutions,solid residues and microbial compositions by scanning electron microscopy,X-ray diffraction,Raman spectroscopy,Fourier transform infrared spectroscopy and 16 S rDNA sequencing revealed the promoting effects of acidified seawater.This acidification can increase the biodissolution of chalcopyrite to increase the concentration of iron ions and maintain the redox potential in the range of 360−410 mV.The latter produces an optimal redox environment conducive to chalcopyrite dissolution via Cu_(2)S.The adaptability of the microbial community to a high-salt environment is improved.Chloride ions at 580 mmol/L improve the leaching kinetics of chalcopyrite by increasing the porosity and noncrystallinity of the intermediate elemental sulfur.This study provides a promising way to bioleaching copper minerals using seawater for areas with freshwater shortages.展开更多
Fermented sour soup is a unique traditional sour food of the Miao and Dong ethnic groups in China.However,due to the commonly used traditional fermentation,the unstable fluctuation of microbial community often leads t...Fermented sour soup is a unique traditional sour food of the Miao and Dong ethnic groups in China.However,due to the commonly used traditional fermentation,the unstable fluctuation of microbial community often leads to some unpleasant inherent off-flavours in rice sour soup.In this study,the microbial composition and volatile flavour components of off-flavour and normal rice sour soup were examined by high-throughput sequencing and headspace solid-phase microextraction coupled with gas chromatography mass spectrometry.Then,based on Pearson correlation coefficients,the correlations between fungi and bacteria and those between core microorganisms and key volatile flavour components were investigated.The dominant fungal genera included Candida,Dekkera,Pichia,Rhizopus,and Issatchenkia,whereas the dominant bacterial genera included Lactobacillus,Pectinatus,Bifidobacterium,Pseudomonas,and Acetobacter.Compared to normal rice sour soup,off-flavoured rice sour soup contained the significantly increased relative abundance of Candida and the significantly decreased relative abundance of Dkkera.In addition,80 volatile flavour compounds detected in off-flavoured rice sour soup,mainly including esters,acids,and alcohols,were different from those detected in normal rice sour soup.Especially,some substances were only detected in off-flavoured rice sour soup,such as 1-hexanol(68-207μg/kg),butyric acid(20-92μg/kg)and heptanoic acid(12-45μg/kg),which might be the main source of off-flavours.These results provide new ideas and strategies of removing or abating odour from fermented rice sour soup.展开更多
Cresyl diphenyl phosphate(CDP),an emerging aryl organophosphate ester(OPE),exhibits potential toxic effects and is frequently found in diverse environmental media,thereby raising concerns about environmental pollution...Cresyl diphenyl phosphate(CDP),an emerging aryl organophosphate ester(OPE),exhibits potential toxic effects and is frequently found in diverse environmental media,thereby raising concerns about environmental pollution.Biodegradation demonstrates substantial potential for CDP removal from the environment.This study investigated the biodegradation mechanisms of CDP using anaerobic activated sludge(AnAS).The biodegradation of 1-mg/L CDP followed a first-order kinetic model with a degradation kinetic constant of 0.943 d^(-1),and the addition of different electron acceptors affected the degradation rate.High-resolution mass spectrometry identified seven transformation products(TPs)of CDP.The pathways of CDP degradation in anaerobic conditions were proposed,with carboxylation products being the most dominant intermediate products.The structure of the anaerobic microbial community at different degradation time points in CDP-amended microcosms was examined.The linear discriminant analysis(LDA)of effect size(LEfSe)potentially underscored the pivotal role of Methyloversatilis in CDP biodegradation.Zebrafish embryotoxicity experiments revealed both lethal and morphogenetic impacts of CDP on zebrafish embryos.The survival rate,hatching rate,and body length indicators of zebrafish embryos underscored the detoxification of CDP and its resultant intermediates by AnAS.This study offers new insights into the fate and biodegradation mechanisms of CDP in wastewater treatment plants.展开更多
The agro-pastoral ecotone epitomizes the ecologically fragile semi-arid zone,where the soil microbiomes play a pivotal role in regulating its multifunctionality.However,whether and how changes in soil structure and or...The agro-pastoral ecotone epitomizes the ecologically fragile semi-arid zone,where the soil microbiomes play a pivotal role in regulating its multifunctionality.However,whether and how changes in soil structure and organic matter composition under different land uses affect microbial community structure remain unclear.Here,land-use types in the agro-pastoral ecotone,including shrubland(BF),artificial grassland(ArG),abandoned grassland(AbG),and maize farmland(MA),were chosen to explore the response relationships between soil microbial communities and the aggregates and dissolved organic matter(DOM)composition.The results showed that compared to MA,the macroaggregates in BF,AbG,and ArG were increased by 123.0,92.79,and 63.71%,respectively,while MA soil had the greatest abundance of<100μm particles.The higher aromatic carbon with high aromaticity and molecular weight in BF soil DOM contributed to its highest mineral-associated organic carbon level(12.61 g kg^(-1)),while MA soil organic carbon had highly efficient decomposition due to its high content of aliphatic and carboxy carbon,so it is prone to loss from the active carbon pools.The transition in land use from shrubland to grassland and farmland has facilitated the conversion of stable aromatic carbon to unstable carboxy carbon.The taxonomic analysis revealed that soil bacterial and fungal communities in the four land uses were dominated by Proteobacteria,Actinobacteriota,Chloroflexi,and Ascomycota.More taxonomic groups from phylum to family were enriched in BF soil.The DOM components and organic carbon are crucial variables shaping the composition of soil bacterial communities,jointly explaining 61.66% of the variance,while aggregates are important variables driving the composition of fungal communities,with an explanation rate of 20.49%.Our results suggest that DOM components and aggregates impact the soil microbial structure;and the transition in land use from agricultural land to grassland and shrubland in the agro-pastoral ecotone enhances aggregate stability,carbon sequestration potential,and microbial diversity.展开更多
The organic matter inmunicipal wastewater can be recovered by anaerobic biological treatment,making further resource utilization of municipal wastewater,which meets the requirements of sustainable development.An upflo...The organic matter inmunicipal wastewater can be recovered by anaerobic biological treatment,making further resource utilization of municipal wastewater,which meets the requirements of sustainable development.An upflow anaerobic biofilter(UAF)treating municipal wastewater was established.The performances of stable operation and recovery operation of UAF after long-term starvation(234 days)and the changes of microbial community structure were researched.By gradually reducing HRT from 10 h to 4 h,the UAF achieved the treatment performance of pre-starvation after only 50 days recovery operation,in which total COD and soluble COD removal efficiencies reached 66%and 69%,respectively,and the CH_(4) production rate was 0.21 L CH_(4)/g CODremoval.The recovery performance of UAF after long term starvation showed that the recovery sequence of three main anaerobic processes was hydrolytic acidification,hydrogen-acetate production and methanogenesis.High-throughput sequencing results indicated that dominant bacteria associated with hydrolytic acidification process changed from Moduliflexaceae and Trichococcus in stable operation stage to Trichococcus and Romboutsia in recovery stage.Besides,the dominant archaea changed from Methanosaeta(hydrotrophic methanogens)to Methanobacterium(acetotrophic methanogens),showing Methanobacterium was more resistant to starvation environment.Therefore,by using UAF for biological treatment of organic matter,even after a long period of starvation,the system would not be completely destroyed.Once it resumed operation,the treatment performance could be restored in a short period of time.展开更多
Anaerobic digestion(AD),as an eco-friendly biological process,shows potential for the decomposition of leachate produced by waste incineration power plants.In this study,the effects of Fe oxides nano-modified pumice(F...Anaerobic digestion(AD),as an eco-friendly biological process,shows potential for the decomposition of leachate produced by waste incineration power plants.In this study,the effects of Fe oxides nano-modified pumice(FNP)were investigated on the fresh leachate AD process.Firstly,a simple hydrothermal method was used to prepare FNP,then introduced into the UASB reactor to evaluate its AD efficiency.Results showed that the inclusion of FNP could shorten the lag phase by 10 days compared to the control group.Furthermore,cumulative methane production in the FNP group was enhanced by 20.11%.Mechanistic studies suggested that hydrogenotrophic methanogenesis in the FNP group was more pronounced due to the influence of key enzymes(i.e.,dehydrogenase and coenzyme F420).Microbial community analysis demonstrated that FNP could enhance the abundance of Methanosarcina,Proteobacteria,Sytrophomonas,and Limnobacter,which might elevate enzyme activity involved in methane production.These findings suggest that FNP might mediate interspecies electron transfer among these microorganisms,which is essential for efficient leachate treatment.展开更多
Cover cropping is a diversifying agricultural practice that can improve soil structure and function by altering the underground litter diversity and soil microbial communities.Here,we tested how a wheat cover crop alt...Cover cropping is a diversifying agricultural practice that can improve soil structure and function by altering the underground litter diversity and soil microbial communities.Here,we tested how a wheat cover crop alters the decomposition of cucumber root litter.A three-year greenhouse litterbag decomposition experiment showed that a wheat cover crop accelerates the decomposition of cucumber root litter.A microcosm litterbag experiment further showed that wheat litter and the soil microbial community could improve cucumber root litter decomposition.Moreover,the wheat cover crop altered the abundances and diversities of soil bacterial and fungal communities,and enriched several putative keystone operational taxonomic units(OTUs),such as Bacillus sp.OTU1837 and Mortierella sp.OTU1236,that were positively related to the mass loss of cucumber root litter.The representative bacterial and fungal strains B186 and M3 were isolated and cultured.In vitro decomposition tests demonstrated that both B186 and M3 had cucumber root litter decomposition activity and a stronger effect was found when they were co-incubated.Overall,a wheat cover crop accelerated cucumber root litter decomposition by altering the soil microbial communities,particularly by stimulating certain putative keystone taxa,which provides a theoretical basis for using cover crops to promote sustainable agricultural development.展开更多
In the context of global COVID-19 epidemic preparedness,the extensive use of disposable surgical masks(DSM)may lead to its emergence as a main new source of microplastics in the environment.Nowadays,DSMs have become a...In the context of global COVID-19 epidemic preparedness,the extensive use of disposable surgical masks(DSM)may lead to its emergence as a main new source of microplastics in the environment.Nowadays,DSMs have become a non-negligible source of plastic waste in aquatic environment,however,less research has been done on DSM after biofilm colonization in freshwater environment.The study investigated the microbial community of DSM-associated biofilms by 16S rRNA gene sequencing.Analysis of the microbial community in the middle and inner/outer layers of the DSM showed that the middle layer was different from the remaining two layers and that potential pathogens were enriched only in the middle layer of the DSM.Herein,we focused on the middle layer and explored the characterization properties and extracellular polymeric substances(EPS)components changes during biofilm formation.The results showed that the EPS components varied with the biofilm incubation time.As the formation of biofilm,the protein(PN)and polysaccharide(PS)in EPS showed an overall increasing trend,and the growth of PS was well synchronized with PN.Three fluorescent components of EPS were determined by the three-dimensional excitation emission matrix(3D-EEM),including humic acid-like,fulvic acid-like,and aromatic protein-like components.The percentage of fluorescent components varied with increasing biofilm development time and then stabilized.Fourier transform infrared spectroscopy(FTIR)characterization results elucidated the emergence of oxygen-containing functional groups during biofilm formation.Moreover,the hydrophilicity increased with biofilm development.In conclusion,the environmental behavior and ecological risks of DSM in aquatic environment deserve urgent attention in future studies.展开更多
Simultaneous nitrification and denitrification(SND)is considered an attractive alternative to traditionally biological nitrogen removal technology.Knowing the effects of heavy metals on the SND process is essential fo...Simultaneous nitrification and denitrification(SND)is considered an attractive alternative to traditionally biological nitrogen removal technology.Knowing the effects of heavy metals on the SND process is essential for engineering.In this study,the responses of SND performance to Zn(Ⅱ)exposure were investigated in a biofilm reactor.The results indicated that Zn(Ⅱ)at low concentration(≤2 mg·L^(-1))had negligible effects on the removal of nitrogen and COD in the SND process compared to that without Zn(Ⅱ),while the removal of ammonium and COD was strongly inhibited with an increasing in the concentration of Zn(Ⅱ)at 5 or 10 mg·L^(-1).Large amounts of extracellular polymeric substance(EPS),especially protein(PN),were secreted to protect microorganisms from the increasing Zn(Ⅱ)damage.High-throughput sequencing analysis indicated that Zn(Ⅱ)exposure could significantly reduce the microbial diversity and change the structure of microbial community.The RDA analysis further confirmed that Azoarcus-Thauera-cluster was the dominant genus in response to low exposure of Zn(Ⅱ)from 1 to 2 mg·L^(-1),while the genus Klebsiella and Enterobacter indicated their adaptability to the presence of elevated Zn(Ⅱ).According to PICRUSt,the abundance of key genes encoding ammonia monooxygenase(EC:1.14.99.39)was obviously reduced after exposure to Zn(Ⅱ),suggesting that the influence of Zn(Ⅱ)on nitrification was greater than that of denitrification,leading to a decrease in ammonium removal of SND system.This study provides a theoretical foundation for understanding the influence of Zn(Ⅱ)on the SND process in a biofilm system,which should be a source of great concern.展开更多
Understanding microbial responses to polycyclic aromatic hydrocarbon(PAH)pollution is crucial for assessing the current status of PAH contamination in polar regions.In this study,intertidal and marine sediments were e...Understanding microbial responses to polycyclic aromatic hydrocarbon(PAH)pollution is crucial for assessing the current status of PAH contamination in polar regions.In this study,intertidal and marine sediments were enriched with a mixture of PAHs(naphthalene,phenanthrene,fluorene,pyrene,and fluoranthene).Isolation of culturable bacteria,high-throughput sequencing,and functional prediction were combined to systematically analyze bacterial structural and predicted functional responses to PAH exposure.High-throughput sequencing results showed that the relative abundance of Proteobacteria was significantly increased after enrichment,and Pseudomonas and Acinetobacter were identified as dominant genera under PAH exposure.These findings were consistent with the 19 potential PAH-degrading strains(mainly Pseudomonas)that were successfully isolated from enrichment cultures.Distinct bacterial taxa between enriched marine and intertidal sediments indicated the existence of distinct PAH-degrading groups.PICRUSt2-based functional predictions suggested higher predicted abundances of PAH-degradation pathways in polar sediments,likely through the preferential degradation of parent PAH compounds in response to elevated concentrations.This study provides valuable data on microbial responses to PAH pollution in polar regions and offers new insights for evaluating ecological hazards induced by PAHs.展开更多
Manganese ion(Mn^(2+))was generated from metallurgical,steel making and chemical industries.It could affect microbial activity and community structure after entering sewage treatment plant.The effect of Mn^(2+)on the ...Manganese ion(Mn^(2+))was generated from metallurgical,steel making and chemical industries.It could affect microbial activity and community structure after entering sewage treatment plant.The effect of Mn^(2+)on the pollutant removal,metal distribution patterns and composition of microbial communities were investigated in a an anaerobic/anoxic/oxic(A^(2)O)process.The results showed that when Mn^(2+)concentration was 5 mg/L,the efficiencies for the removal of chemical oxygen demand(COD),total nitrogen(TN)and total phosphorus(TP)attained remarkable levels of 96%,93%,and 99%,respectively.In the sludge,the distribution pattern of Mn^(2+)concentration was tightly bound extracellular polymeric substances(TB-EPS)>supernatant>loosely bound EPS(LB-EPS)>soluble microbial products(SMP).Mn^(2+)was found to enrich and accumulate in the microorganism cells.In addition,Mn^(2+)was mainly found in residual fractions and reducible fractions of pellet that manganese was present.The pellet was discovered to contain a substantial quantity of manganese,which was present in various oxidation states,including Mn^(4+),Mn^(3+)and Mn^(2+).The escalating levels of Mn^(2+)led to a reduction in the richness and diversity of microbial communities inhabiting various regions of the A^(2)O reactor.Nonetheless,the uniformity experienced only subtle alterations.Proteobacteria and Bacteroidetes emerged as the leading phyla within the microbial ecosystem,experiencing a steady rise in their respective proportions.The dominant bacterial groups,Azospira and Dechromonas,experienced an incremental increase in their relative prevalence,which played a constructive role in the process of pollutant removal.展开更多
Soil microbial communities play a crucial role in forest ecological processes,but the differences between rhizosphere and non-rhizosphere soils,as well as their variations with stand ages remain unclear.We collected r...Soil microbial communities play a crucial role in forest ecological processes,but the differences between rhizosphere and non-rhizosphere soils,as well as their variations with stand ages remain unclear.We collected rhizosphere and non-rhizosphere soils in Castanopsis hystrix plantations at ages(6,10,15,25,30 and 34 years)in the southern subtropics and analyzed soil microbial communities using the phospholipid fatty acid(PLFA)method.There were significant differences in microbial communities between the two.Rhizosphere soils had higher total PLFAs and fungal to bacterial(F:B)ratios,and lower arbuscular mycorrhizal fungi to ectomycorrhizal fungi(AMF:EMF)ratios in the 34-year-old stand but microbial communities in non-rhizosphere soils showed no changes with stand age.Rhizosphere soils had higher total PLFAs and F:B ratios but lower AMF:EMF ratios.Further analysis revealed a strong correlation between fine root nutrients and rhizosphere soil PLFAs,indicating a closer interaction between root exudates and microbial communities.In contrast,non-rhizosphere soil PLFAs appeared to be more influenced by soil nitrogen availability.Overall,soil microbial communities exhibited significant differences between rhizosphere and non-rhizosphere soils over various stand ages.A strong correlation was observed between rhizosphere soil PLFAs and fine root nutrients,which may improve our understanding of forest management strategies.展开更多
基金funded by the Beef Cattle Research Council Cluster(FDE.18.21C)Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery,NSERC Canadian Research Chair(Tier 1)program+2 种基金NSERC Alliance program(ALLRP 588541‐23)Foundation for Food&Agriculture Research Greener Cattle Initiative(Award ID 22‐000373)DSM Nutritional Products,Kaiseraugst,Switzerland。
文摘Background The enteric methane inhibitor 3-nitrooxypropanol(3-NOP)inhibits the key enzyme in ruminal methanogenesis,but whether short-term(ST)and long-term(LT)dietary supplementation has similar effects on rumen microbiota in beef cattle and how microbes change after 3-NOP withdrawal have not been studied.This study investigated changes in rumen bacteria,archaea,and protozoa after ST and LT dietary supplementation and removal of 3-NOP using metataxonomic analysis.Results A total of 143 rumen samples were collected from two beef cattle studies with 3-NOP supplementation.The ST study(95 samples)used eight ruminally cannulated beef cattle in a 4×4 Latin square design with four 28-d of 3-NOP treatments[mg/kg of dry matter(DM)]:control:0,low:53,med:161,and high:345.The LT study(48 samples)was a completely randomized design with two 3-NOP treatments[control:0,and high:280 mg/kg of DM)fed for 112-d followed by a 16-d withdrawal(without 3-NOP).Bacterial and archaeal communities were significantly affected by 3-NOP supplementation but limited effects on protozoal communities were observed.Under ST supplementation,the relative abundances of Prevotella,Methanobrevibacter(Mbb.)ruminantium,Methanosphaera sp.ISO3-F5,and Entodinium were increased(Q<0.05),whereas those of Mbb.gottschalkii and Epidinium were decreased(Q<0.05)with 3-NOP supplementation.In LT study,relative abundances of Mbb.ruminantium,and Methanosphaera sp.Group5 were increased(Q<0.05),while those of Saccharofermentans and Mbb.gottschalkii were decreased(Q<0.05)with 3-NOP supplementation.Comparison between 3-NOP supplementation and the withdrawal revealed increased relative abundances of Clostridia UCG-014 and Oscillospiraceae NK4A214 group and decreased those of Eubacterium nodatum group and Methanosphaera sp.Group5(P<0.05)after 3-NOP withdrawal.Further comparison of rumen microbiota between control and 3-NOP withdrawal showed significantly higher(P=0.029)relative abundances of Eggerthellaceae DNF00809,p-1088-a5 gut group,and Family XII UCG-001 in control group while no significant differences were detected for archaea and protozoa.Microbial network analysis revealed that microbial interactions differed by both 3-NOP dose and durations.Conclusions Both ST and LT supplementation affected overall rumen microbial profile,with individual microbial groups responded to 3-NOP supplementation differently.After 3-NOP withdrawal,not all microbes showed recovery,indicating that the 3-NOP driven shifts were only partially reversible.These findings provide an understanding of the effects of 3-NOP on rumen microbial communities and their adaptability to methane mitigation strategies.
基金financially supported by National Science and Technology Major Projects(Grant Nos.2016ZX05050,2017ZX05001002-008)CNPC Major Projects(Grant No.2021DJ2203)The Open Fund by the State Key Laboratory of Continental Dynamics,Northwest University and the Key Laboratory for Digital Land and Resources of Jiangxi Province(Grant No.DLLJ202017)。
文摘The formation of Mesozoic natural gas in the Pengyang area of southwestern Ordos Basin is discussed,from the perspective of microbial community characteristics,in order to clarify the relationship between the origin of natural gas and its associated indigenous microbial community.The types and diversity of indigenous microbial communities associated with the oil reservoir were studied by means of collecting reservoir formation water samples from exploration wells.The indigenous microbial communities in the Chang 8 member of the Yanchang Formation were primarily distributed within Proteobacteria and Firmicutes,including the specific species and genera of Methylobacter,Pseudomonas,Haibacter,Toxobacillus,Acinetobacter and Adura actinomyces.The results of diversity analysis shows that the number of common genes was 5448,while the number of unique genes and information was less.This reflects the fact that the strata in the study area are relatively closed and not invaded by external water sources,which leads to the development of biological community diversity.In conjunction with the analysis of geochemical characteristics of oil and gas reservoirs in this area,this indicates that the study area possesses the necessary geological conditions for microbial degradation.It is the first time that the species and diversity of the indigenous microbial community in the Ordos Basin have been analyzed,showing that microbial degradation is the main cause of natural gas formation here,changes the characteristics of crude oil in this area and provides first-hand information on the impact of indigenous microorganisms on the reservoir.
基金supported by the Guangdong Special Support ProgramProject(No.2021JC060580)the Foshan Innovation Team Project(No.2130218003140).
文摘In this study,the effects of different salinity gradients and addition of compatible solutes on anaerobic treated effluent water qualities,sludge characteristics and microbial communities were investigated.The increase in salinity resulted in a decrease in particle size of the granular sludge,which was concentrated in the range of 0.5-1.0 mm.The content of EPS(extracellular polymeric substances)in the granular sludge gradually increased with increasing salinity and the addition of betaine(a typical compatible solute).Meanwhile,the microbial community structure was significantly affected by salinity,with high salinity reducing the diversity of bacteria.At higher salinity,Patescibacteria and Proteobacteria gradually became the dominant phylum,with relative abundance increasing to 13.53%and 12.16%at 20 g/L salinity.Desulfobacterota and its subordinate Desulfovibrio,which secrete EPS in large quantities,dominated significantly after betaine addition.Their relative abundance reached 13.65%and 7.86%at phylum level and genus level.The effect of these changes on the treated effluent was shown as the average chemical oxygen demand(COD)removal rate decreased from 82.10%to 79.71%,78.01%,68.51%and 64.55%when the salinity gradually increased from 2 g/L to 6,10,16 and 20 g/L.At the salinity of 20 g/L,average COD removal increased to 71.65%by the addition of 2 mmol/L betaine.The gradient elevated salinity and the exogenous addition of betaine played an important role in achieving stability of the anaerobic system in a highly saline environment,which provided a feasible strategy for anaerobic treatment of organic saline wastewater.
基金supported by the National Natural Science Foundation of China(No.42377415)the Natural Science Foundation of Sichuan Province(No.2023NSFSC0811),Sichuan Science and Technology Program(Nos.2021JDTD0013 and 2021YFQ0066)+1 种基金the Science and Technology Major Project of Xizhang Autonomous Region of China(No.XZ202201ZD0004G06)the Everest Scientific Research Program(No.80000-2023ZF11405).
文摘The large-scale exploitation of vanadium(Ⅴ) bearing minerals has led to a massive accumulation of Ⅴ tailings, of which Ⅴ pollution poses severe ecological risks. Although the mechanisms of Ⅴ stress to the microbial community have been reported, the influential pathways in a multi-medium-containing system, for example, the soil-tailings-groundwater system,are unknown. The dynamic redox conditions and substance exchange within the system exhibited complex Ⅴ stress on the local microbial communities. In this study, the influence pathways of Ⅴ stress to the microbial community in the soil-tailings-groundwater system were first investigated. High Ⅴ contents were observed in groundwater(139.2 ± 0.15 μg/L) and soil(98.0–323.8 ± 0.02 mg/kg), respectively. Distinct microbial composition was observed for soil and groundwater, where soil showed the highest level of diversity and richness. Firmicutes, Proteobacteria, Actinobacteria, and Acidobacteria were dominant in soil and groundwater with a sum relative abundance of around 80 %. Based on redundancy analysis and structural equation models, Ⅴ was one of the vital driving factors affecting microbial communities. Groundwater microbial communities were influenced by Ⅴ via Cr, dissolved oxygen, and total nitrogen, while Fe, Mn, and total phosphorus were the key mediators for Ⅴ to affect soil microbial communities. Ⅴ affected the microbial community via metabolic pathways related to carbonaceous matter, which was involved in the establishment of survival strategies for metal stress. This study provides novel insights into the influence pathways of Ⅴ on the microorganisms in tailings reservoir for pollution bioremediation.
基金supported by the Key Research Program of Wuhan(No.2022022202015015)the State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(No.2022TS13)+1 种基金the key projects of National Natural Science Foundation of China(No.2019YFC0408503)Shanghai Tongji Gao Tingyao Environmental Technology Development Foundation.
文摘Microalgae-bacteria system is an emerging alternative for sustainable wastewater treatment.Exploring the structure and diversity of microbial community in microalgae-bacteria system under sulfadiazine stress can contribute to the understanding of the sulfadiazine behavior in environments.Furthermore,as important carriers of antibiotic resistance genes(ARGs),microalgae can influence the profiles of ARGs either directly or indirectly through the secretion of metabolites.However,the effects of sulfadiazine on ARGs dissemination of microalgae-bacteria systems remain underreported.Herein,the impacts of sulfadiazine(1 mg/L)on the structural diversity and metabolic activity of microorganisms were examined in microalgae-bacteria systems.Results showed thatmicroalgae-bacteria system could remove NH_(4)^(+)-N better(about 72.3%)than activated sludge system,and hydrolysis was the first step in sulfadiazine degradation.A high level of intI1(5.7×10^(4) copies/mL)was detected in the initial media of the microalgae-bacteria system.Microalgae could hamper the rate of horizontal gene transfer activation.Compared with activated sludge system,the abundance of sul genes(sul1,sul2,sul3,and sulA)was significantly lowered after treating with microalgae-bacteria system.Additionally,the number of proteins and the sum of polysaccharides in the extracellular polymeric substances of the activated sludge system were lower than those of themicroalgae-bacteria system.Microalgae can altermicrobial communities.The genus Rozellomycota predominated all samples.Fungi with relatively high abundance increased in the microalgae-bacteria system,including Dipodascaceae,Rhodotorula,and Geotrichum.These results offer valuable insights into the application processes involving microalgae-bacteria system.
基金supported by the National Key Research and Development Program of China(Nos.2018YFA0901100 and 2018YFC1801103)the National Natural Science Foundation of China(Nos.22206202 and 22076216)。
文摘The problem of soil polycyclic aromatic hydrocarbon(PAH)pollution in coking plant sites has been widely studied in recent years,but there is a lack of research on the correlation between soil microorganisms,soil metabolomics,and soil properties.Thus,in this study,the long-term impact of coke combustion on soil microbial community structure,enzyme activities,and metabolic pathways within a former coking plant site was investigated.Soil samples were collected from both the coking production area(CA group)and office area(OLA group),approximately 0 to 20 cm in depth.Compared with OLA group,elevated levels of 16 PAHs in the list of US EPA were detected by gas chromatography-mass spectrometry in the CA group.Several dominant microorganisms,such as Altererythrobacter,Lysobacter,and Sulfurifustis,were identified by 16 s ribosomal DNA sequencing in the CA group.The fatty acid biosynthesis pathway exhibited specific inhibition,while the phenylalanine metabolic pathwaywas promoted in response to PAH stress.Long-term PAH exposure led to the inhibition of soil urease activity.The co-occurrence network ofmicroorganisms revealed intricate patterns of co-metabolism and co-adaptation within complex bacterial communities,facilitating their adaptation to and decomposition of soil-borne PAHs.This research could provide valuable insights into the community characteristics andmetabolic mechanisms of microorganisms inhabiting PAH-polluted soil within coking plant sites.The findings enhance our understanding of the indigenous soil microbiome and its intricate network dynamics under the persistent stress of PAHs,contributing to a more comprehensive knowledge of soil ecosystems in such environments.
基金supported by the Educational Commission of Anhui Province of China(No.KJ2021A0168)the Research Fund of Anhui Agricultural University(No.rc422112).
文摘The environmental impacts of acid mine drainage(AMD)from open-pit mining are profoundly detrimental,yet knowledge about its effects on paddy soil microbial communities,especially at greater depths,remains limited.In this investigation,we compared soils affected by AMD versus unaffected soil depth profiles in terms of bacterial diversity and community assembly.The profiles in AMD-polluted soils exhibited tight geochemical gradients,characterized by increased acidity,SO_(4)^(2-),NO_(3)^(-),and heavy metal content compared to unpolluted soils.Notably,AMD significantly diminished soil bacterial biodiversity.A depthwise analysis showed distinct microbial stratification,with certain bacteria like Candidatus_Solibacter and Candidatus_Koribacter predominated in polluted soils,while others like Haliangium and Nitrospira were more prevalent in control soils.Interestingly,despite variable soil conditions,predictedmetabolic pathways,particularly those involving carbon,nitrogen,and sulfur,showed relative stability.AMD pollution induced the upregulation of methylcoenzyme M reductase and sulfate reductase genes.Bacterial communities were more responsive to pH and nutrient content rather than heavy metals,with pH and SO_(4)^(2-)being the primary drivers of microbial diversity and distribution.Additionally,pHwas identified as the most significant influence on the predicted methane,sulfur,and nitrogen metabolism.Furthermore,deterministic processes played a more significant role in community assembly of polluted soils,while heterogeneous selection gained importance with increasing depth in control soils.Additionally,microbial co-occurrences,particularly positive interactions,were more prevalent in the polluted soils with reduced network modularity and keystone taxa.These findings offer insights into sustaining microbial diversity in extreme environments.
基金supported by grant from the National Key Research and Development Program of China(2021YFC2101402)the National Natural Science Foundation of China(31972064,32302030)the China Postdoctoral Science Foundation(2023M731334)。
文摘Fermented chili products are popular traditional fermented foods around the world.However,differences in microbial communities in fermented chilies from different regions and how they affect the flavor compounds in chili fermentation have not been reported.In this study,the dynamics of flavor compounds and microbial communities in fermented chilies from Sichuan,Guizhou,and Hunan were systematically investigated by macro-genome sequencing,solid phase microextraction-gas chromatograph-mass spectrometry(SPME-GC-MS),electronic nose,and electronic tongue techniques.Simultaneously,the microbial metabolic mechanisms and the relationship between flavor compounds and microbiome were unraveled through staged and simulated fermentation analysis.The results showed that 53 chemical odorants,including alcohols,esters,aldehydes,and acids,were identified as chemical markers to differentiate the regional samples.A total of 12 microbial species,including Staphylococcus xylosus,unclassified Staphylococcus species,Weissella confusus,Lactococcus cremoris,Lactococcus garvieae,Lactiplantibacillus sakei,Pediciococcus propionicigenes,Pediciococcus idahonensis,Pediciococcus aciditolerans,Nocardioides antri,Debaryomyces hansenii,and Colletotrichum scovillei,were identified as microbial markers to differentiate the regional samples.Correlation analysis showed that Lactobacillaceae was associated with fruity,floral,spicy,and fatty aromas.The electronic nose and tongue analysis results showed that 9 flavor and 8 taste indicators significantly differed between regional samples(P<0.05).Additionally,flavor compounds and microbial diversity were robust under initial selection stress and showed higher diversity under metabolome-microbiome interactions.Importantly,simulated fermentation confirmed that metabolome-microbiome interactions drove the shift in microbial structure,metabolism,and flavor in regionally fermented chilies.These results provide insights into the succession of microbial communities and the formation of flavor compounds in chili fermentation,which may enable the future replication of fermented foods with the same flavor.
基金Project(2022YFC2105300)supported by the National Key Research and Development Program of ChinaProjects(41802038,51774342)supported by the National Natural Science Foundation of China。
文摘The enhancement of chalcopyrite bioleaching with an enriched microbial community by acidified seawater was studied,and the enhancing mechanism was analyzed.The microbial community was enriched at the Dabaoshan mine site,and the treated ore sample had high concentrations of chalcopyrite and galena.The experimental results show that copper extraction from chalcopyrite with an enriched microbial community in seawater was promoted from 13.1%to 62.1%by acidification in comparison with that without acidification.Further analyses of the solutions,solid residues and microbial compositions by scanning electron microscopy,X-ray diffraction,Raman spectroscopy,Fourier transform infrared spectroscopy and 16 S rDNA sequencing revealed the promoting effects of acidified seawater.This acidification can increase the biodissolution of chalcopyrite to increase the concentration of iron ions and maintain the redox potential in the range of 360−410 mV.The latter produces an optimal redox environment conducive to chalcopyrite dissolution via Cu_(2)S.The adaptability of the microbial community to a high-salt environment is improved.Chloride ions at 580 mmol/L improve the leaching kinetics of chalcopyrite by increasing the porosity and noncrystallinity of the intermediate elemental sulfur.This study provides a promising way to bioleaching copper minerals using seawater for areas with freshwater shortages.
基金funded by National Natural Science Foundation of China(32360568)Science and Technology Plan Project of Guizhou Province(Qian Ke He Chengguo[2023]Zhongda 011)+2 种基金Guizhou Basic Research Program(Natural Science)Mianshang Project(Qiankehe Basic MS[2025]671)Guizhou Provincial Association of Science and Technology Youth Science and Technology Talent Support Project(GASTYESS202407)Guizhou University Natural Science Specialized(Te Gang)Scientific Research Fund(Gui Da Te Gang He Zi(2022)39).
文摘Fermented sour soup is a unique traditional sour food of the Miao and Dong ethnic groups in China.However,due to the commonly used traditional fermentation,the unstable fluctuation of microbial community often leads to some unpleasant inherent off-flavours in rice sour soup.In this study,the microbial composition and volatile flavour components of off-flavour and normal rice sour soup were examined by high-throughput sequencing and headspace solid-phase microextraction coupled with gas chromatography mass spectrometry.Then,based on Pearson correlation coefficients,the correlations between fungi and bacteria and those between core microorganisms and key volatile flavour components were investigated.The dominant fungal genera included Candida,Dekkera,Pichia,Rhizopus,and Issatchenkia,whereas the dominant bacterial genera included Lactobacillus,Pectinatus,Bifidobacterium,Pseudomonas,and Acetobacter.Compared to normal rice sour soup,off-flavoured rice sour soup contained the significantly increased relative abundance of Candida and the significantly decreased relative abundance of Dkkera.In addition,80 volatile flavour compounds detected in off-flavoured rice sour soup,mainly including esters,acids,and alcohols,were different from those detected in normal rice sour soup.Especially,some substances were only detected in off-flavoured rice sour soup,such as 1-hexanol(68-207μg/kg),butyric acid(20-92μg/kg)and heptanoic acid(12-45μg/kg),which might be the main source of off-flavours.These results provide new ideas and strategies of removing or abating odour from fermented rice sour soup.
基金supported by the National Natural Science Foundation of China(Grants No.52270155 and 92047201).
文摘Cresyl diphenyl phosphate(CDP),an emerging aryl organophosphate ester(OPE),exhibits potential toxic effects and is frequently found in diverse environmental media,thereby raising concerns about environmental pollution.Biodegradation demonstrates substantial potential for CDP removal from the environment.This study investigated the biodegradation mechanisms of CDP using anaerobic activated sludge(AnAS).The biodegradation of 1-mg/L CDP followed a first-order kinetic model with a degradation kinetic constant of 0.943 d^(-1),and the addition of different electron acceptors affected the degradation rate.High-resolution mass spectrometry identified seven transformation products(TPs)of CDP.The pathways of CDP degradation in anaerobic conditions were proposed,with carboxylation products being the most dominant intermediate products.The structure of the anaerobic microbial community at different degradation time points in CDP-amended microcosms was examined.The linear discriminant analysis(LDA)of effect size(LEfSe)potentially underscored the pivotal role of Methyloversatilis in CDP biodegradation.Zebrafish embryotoxicity experiments revealed both lethal and morphogenetic impacts of CDP on zebrafish embryos.The survival rate,hatching rate,and body length indicators of zebrafish embryos underscored the detoxification of CDP and its resultant intermediates by AnAS.This study offers new insights into the fate and biodegradation mechanisms of CDP in wastewater treatment plants.
基金funded by the Inner Mongolia Local Science and Technology Development Fund Projects,China(2021GG0393)。
文摘The agro-pastoral ecotone epitomizes the ecologically fragile semi-arid zone,where the soil microbiomes play a pivotal role in regulating its multifunctionality.However,whether and how changes in soil structure and organic matter composition under different land uses affect microbial community structure remain unclear.Here,land-use types in the agro-pastoral ecotone,including shrubland(BF),artificial grassland(ArG),abandoned grassland(AbG),and maize farmland(MA),were chosen to explore the response relationships between soil microbial communities and the aggregates and dissolved organic matter(DOM)composition.The results showed that compared to MA,the macroaggregates in BF,AbG,and ArG were increased by 123.0,92.79,and 63.71%,respectively,while MA soil had the greatest abundance of<100μm particles.The higher aromatic carbon with high aromaticity and molecular weight in BF soil DOM contributed to its highest mineral-associated organic carbon level(12.61 g kg^(-1)),while MA soil organic carbon had highly efficient decomposition due to its high content of aliphatic and carboxy carbon,so it is prone to loss from the active carbon pools.The transition in land use from shrubland to grassland and farmland has facilitated the conversion of stable aromatic carbon to unstable carboxy carbon.The taxonomic analysis revealed that soil bacterial and fungal communities in the four land uses were dominated by Proteobacteria,Actinobacteriota,Chloroflexi,and Ascomycota.More taxonomic groups from phylum to family were enriched in BF soil.The DOM components and organic carbon are crucial variables shaping the composition of soil bacterial communities,jointly explaining 61.66% of the variance,while aggregates are important variables driving the composition of fungal communities,with an explanation rate of 20.49%.Our results suggest that DOM components and aggregates impact the soil microbial structure;and the transition in land use from agricultural land to grassland and shrubland in the agro-pastoral ecotone enhances aggregate stability,carbon sequestration potential,and microbial diversity.
基金supported by the National Natural Science Foundation of China(No.52270018).
文摘The organic matter inmunicipal wastewater can be recovered by anaerobic biological treatment,making further resource utilization of municipal wastewater,which meets the requirements of sustainable development.An upflow anaerobic biofilter(UAF)treating municipal wastewater was established.The performances of stable operation and recovery operation of UAF after long-term starvation(234 days)and the changes of microbial community structure were researched.By gradually reducing HRT from 10 h to 4 h,the UAF achieved the treatment performance of pre-starvation after only 50 days recovery operation,in which total COD and soluble COD removal efficiencies reached 66%and 69%,respectively,and the CH_(4) production rate was 0.21 L CH_(4)/g CODremoval.The recovery performance of UAF after long term starvation showed that the recovery sequence of three main anaerobic processes was hydrolytic acidification,hydrogen-acetate production and methanogenesis.High-throughput sequencing results indicated that dominant bacteria associated with hydrolytic acidification process changed from Moduliflexaceae and Trichococcus in stable operation stage to Trichococcus and Romboutsia in recovery stage.Besides,the dominant archaea changed from Methanosaeta(hydrotrophic methanogens)to Methanobacterium(acetotrophic methanogens),showing Methanobacterium was more resistant to starvation environment.Therefore,by using UAF for biological treatment of organic matter,even after a long period of starvation,the system would not be completely destroyed.Once it resumed operation,the treatment performance could be restored in a short period of time.
基金supported by the National Key Research and Development Program of China(No.2019YFC0408500)the Scientific Research Project of China State Construction Engineering Corporation Limited(CSCEC-2022-K-(36))the Scientific Research Project of CSCEC AECOM Consultants Corporation Limited(XBSZKY2216).
文摘Anaerobic digestion(AD),as an eco-friendly biological process,shows potential for the decomposition of leachate produced by waste incineration power plants.In this study,the effects of Fe oxides nano-modified pumice(FNP)were investigated on the fresh leachate AD process.Firstly,a simple hydrothermal method was used to prepare FNP,then introduced into the UASB reactor to evaluate its AD efficiency.Results showed that the inclusion of FNP could shorten the lag phase by 10 days compared to the control group.Furthermore,cumulative methane production in the FNP group was enhanced by 20.11%.Mechanistic studies suggested that hydrogenotrophic methanogenesis in the FNP group was more pronounced due to the influence of key enzymes(i.e.,dehydrogenase and coenzyme F420).Microbial community analysis demonstrated that FNP could enhance the abundance of Methanosarcina,Proteobacteria,Sytrophomonas,and Limnobacter,which might elevate enzyme activity involved in methane production.These findings suggest that FNP might mediate interspecies electron transfer among these microorganisms,which is essential for efficient leachate treatment.
基金supported by the National Natural Science Foundation of China(32072655 and 32272792)。
文摘Cover cropping is a diversifying agricultural practice that can improve soil structure and function by altering the underground litter diversity and soil microbial communities.Here,we tested how a wheat cover crop alters the decomposition of cucumber root litter.A three-year greenhouse litterbag decomposition experiment showed that a wheat cover crop accelerates the decomposition of cucumber root litter.A microcosm litterbag experiment further showed that wheat litter and the soil microbial community could improve cucumber root litter decomposition.Moreover,the wheat cover crop altered the abundances and diversities of soil bacterial and fungal communities,and enriched several putative keystone operational taxonomic units(OTUs),such as Bacillus sp.OTU1837 and Mortierella sp.OTU1236,that were positively related to the mass loss of cucumber root litter.The representative bacterial and fungal strains B186 and M3 were isolated and cultured.In vitro decomposition tests demonstrated that both B186 and M3 had cucumber root litter decomposition activity and a stronger effect was found when they were co-incubated.Overall,a wheat cover crop accelerated cucumber root litter decomposition by altering the soil microbial communities,particularly by stimulating certain putative keystone taxa,which provides a theoretical basis for using cover crops to promote sustainable agricultural development.
基金Supported by the Natural Science Foundation of Shandong Province(Nos.ZR2022MD115,ZR202111160067)。
文摘In the context of global COVID-19 epidemic preparedness,the extensive use of disposable surgical masks(DSM)may lead to its emergence as a main new source of microplastics in the environment.Nowadays,DSMs have become a non-negligible source of plastic waste in aquatic environment,however,less research has been done on DSM after biofilm colonization in freshwater environment.The study investigated the microbial community of DSM-associated biofilms by 16S rRNA gene sequencing.Analysis of the microbial community in the middle and inner/outer layers of the DSM showed that the middle layer was different from the remaining two layers and that potential pathogens were enriched only in the middle layer of the DSM.Herein,we focused on the middle layer and explored the characterization properties and extracellular polymeric substances(EPS)components changes during biofilm formation.The results showed that the EPS components varied with the biofilm incubation time.As the formation of biofilm,the protein(PN)and polysaccharide(PS)in EPS showed an overall increasing trend,and the growth of PS was well synchronized with PN.Three fluorescent components of EPS were determined by the three-dimensional excitation emission matrix(3D-EEM),including humic acid-like,fulvic acid-like,and aromatic protein-like components.The percentage of fluorescent components varied with increasing biofilm development time and then stabilized.Fourier transform infrared spectroscopy(FTIR)characterization results elucidated the emergence of oxygen-containing functional groups during biofilm formation.Moreover,the hydrophilicity increased with biofilm development.In conclusion,the environmental behavior and ecological risks of DSM in aquatic environment deserve urgent attention in future studies.
基金supported by the Shanxi Province Science Foundation for Youths(20210302124348 and 202103021223099)the Basic Research Project for the ShanxiZheda Institute of Advanced Materials and Chemical Engineering(2021SX-AT004)the National Natural Science Foundation of China(51778397).
文摘Simultaneous nitrification and denitrification(SND)is considered an attractive alternative to traditionally biological nitrogen removal technology.Knowing the effects of heavy metals on the SND process is essential for engineering.In this study,the responses of SND performance to Zn(Ⅱ)exposure were investigated in a biofilm reactor.The results indicated that Zn(Ⅱ)at low concentration(≤2 mg·L^(-1))had negligible effects on the removal of nitrogen and COD in the SND process compared to that without Zn(Ⅱ),while the removal of ammonium and COD was strongly inhibited with an increasing in the concentration of Zn(Ⅱ)at 5 or 10 mg·L^(-1).Large amounts of extracellular polymeric substance(EPS),especially protein(PN),were secreted to protect microorganisms from the increasing Zn(Ⅱ)damage.High-throughput sequencing analysis indicated that Zn(Ⅱ)exposure could significantly reduce the microbial diversity and change the structure of microbial community.The RDA analysis further confirmed that Azoarcus-Thauera-cluster was the dominant genus in response to low exposure of Zn(Ⅱ)from 1 to 2 mg·L^(-1),while the genus Klebsiella and Enterobacter indicated their adaptability to the presence of elevated Zn(Ⅱ).According to PICRUSt,the abundance of key genes encoding ammonia monooxygenase(EC:1.14.99.39)was obviously reduced after exposure to Zn(Ⅱ),suggesting that the influence of Zn(Ⅱ)on nitrification was greater than that of denitrification,leading to a decrease in ammonium removal of SND system.This study provides a theoretical foundation for understanding the influence of Zn(Ⅱ)on the SND process in a biofilm system,which should be a source of great concern.
基金supported by the project from the National Natural Science Foundation of China(Grant no.42230411)the Science&Technology Innovation Project of Laoshan Laboratory(Grant no.LSKJ202203206)。
文摘Understanding microbial responses to polycyclic aromatic hydrocarbon(PAH)pollution is crucial for assessing the current status of PAH contamination in polar regions.In this study,intertidal and marine sediments were enriched with a mixture of PAHs(naphthalene,phenanthrene,fluorene,pyrene,and fluoranthene).Isolation of culturable bacteria,high-throughput sequencing,and functional prediction were combined to systematically analyze bacterial structural and predicted functional responses to PAH exposure.High-throughput sequencing results showed that the relative abundance of Proteobacteria was significantly increased after enrichment,and Pseudomonas and Acinetobacter were identified as dominant genera under PAH exposure.These findings were consistent with the 19 potential PAH-degrading strains(mainly Pseudomonas)that were successfully isolated from enrichment cultures.Distinct bacterial taxa between enriched marine and intertidal sediments indicated the existence of distinct PAH-degrading groups.PICRUSt2-based functional predictions suggested higher predicted abundances of PAH-degradation pathways in polar sediments,likely through the preferential degradation of parent PAH compounds in response to elevated concentrations.This study provides valuable data on microbial responses to PAH pollution in polar regions and offers new insights for evaluating ecological hazards induced by PAHs.
基金supported by Jilin Provincial Department of Education Science and Technology Project(No.JJKH20230152KJ)the Doctoral Research Initiation Fund(No.BSJXM-2022215).
文摘Manganese ion(Mn^(2+))was generated from metallurgical,steel making and chemical industries.It could affect microbial activity and community structure after entering sewage treatment plant.The effect of Mn^(2+)on the pollutant removal,metal distribution patterns and composition of microbial communities were investigated in a an anaerobic/anoxic/oxic(A^(2)O)process.The results showed that when Mn^(2+)concentration was 5 mg/L,the efficiencies for the removal of chemical oxygen demand(COD),total nitrogen(TN)and total phosphorus(TP)attained remarkable levels of 96%,93%,and 99%,respectively.In the sludge,the distribution pattern of Mn^(2+)concentration was tightly bound extracellular polymeric substances(TB-EPS)>supernatant>loosely bound EPS(LB-EPS)>soluble microbial products(SMP).Mn^(2+)was found to enrich and accumulate in the microorganism cells.In addition,Mn^(2+)was mainly found in residual fractions and reducible fractions of pellet that manganese was present.The pellet was discovered to contain a substantial quantity of manganese,which was present in various oxidation states,including Mn^(4+),Mn^(3+)and Mn^(2+).The escalating levels of Mn^(2+)led to a reduction in the richness and diversity of microbial communities inhabiting various regions of the A^(2)O reactor.Nonetheless,the uniformity experienced only subtle alterations.Proteobacteria and Bacteroidetes emerged as the leading phyla within the microbial ecosystem,experiencing a steady rise in their respective proportions.The dominant bacterial groups,Azospira and Dechromonas,experienced an incremental increase in their relative prevalence,which played a constructive role in the process of pollutant removal.
基金funded by the Science and Technology Program of Guangdong(Grant Nos 2024B1212080005 and2024B1212070012)the National Natural Science Foundation of China(Grant Nos 32101342 and 42207158)+1 种基金Guangdong Flagship Project of Basic and Applied Basic Research(Grant No 2023B0303050001)the Science and Technology Projects in Guangzhou(Grant No E33309)。
文摘Soil microbial communities play a crucial role in forest ecological processes,but the differences between rhizosphere and non-rhizosphere soils,as well as their variations with stand ages remain unclear.We collected rhizosphere and non-rhizosphere soils in Castanopsis hystrix plantations at ages(6,10,15,25,30 and 34 years)in the southern subtropics and analyzed soil microbial communities using the phospholipid fatty acid(PLFA)method.There were significant differences in microbial communities between the two.Rhizosphere soils had higher total PLFAs and fungal to bacterial(F:B)ratios,and lower arbuscular mycorrhizal fungi to ectomycorrhizal fungi(AMF:EMF)ratios in the 34-year-old stand but microbial communities in non-rhizosphere soils showed no changes with stand age.Rhizosphere soils had higher total PLFAs and F:B ratios but lower AMF:EMF ratios.Further analysis revealed a strong correlation between fine root nutrients and rhizosphere soil PLFAs,indicating a closer interaction between root exudates and microbial communities.In contrast,non-rhizosphere soil PLFAs appeared to be more influenced by soil nitrogen availability.Overall,soil microbial communities exhibited significant differences between rhizosphere and non-rhizosphere soils over various stand ages.A strong correlation was observed between rhizosphere soil PLFAs and fine root nutrients,which may improve our understanding of forest management strategies.
