Effluents from wastewater treatment plants（WWTPs） containing microorganisms and residual nutrients can influence the biofilm formation. Although the process and mechanism of bacterial biofilm formation have been wel...Effluents from wastewater treatment plants（WWTPs） containing microorganisms and residual nutrients can influence the biofilm formation. Although the process and mechanism of bacterial biofilm formation have been well characterized, little is known about the characteristics and interaction of bacteria, archaea and eukaryotes in the early colonization, especially under the influence of WWTP effluent. The aim of this study was to characterize the important bacterial, archaeal and eukaryotic species in the early stage of biofilm formation downstream of the WWTP outlet. Water and biofilm samples were collected 24 and 48 hr after the deposition of bio-cords in the stream. Illumina Miseq sequencing of the 16 S and 18 S rDNA showed that, among the three domains, the bacterial biofilm community had the largest alpha and beta diversity. The early bacterial colonizers appeared to be ＂biofilm-specific＂, with only a few dominant operational taxonomic units（OTUs） shared between the biofilm and the ambient water environment. Alpha-proteobacteria and Ciliophora tended to dominate the bacterial and eukaryotic communities, respectively, of the early biofilm already at 24 hr, whereas archaea played only a minor role during the early stage of colonization. The network analysis showed that the three domains of microbial community connected highly during the early colonization and it might be a characteristic of the microbial communities in the biofilm formation process where co-occurrence relationships could drive coexistence and diversity maintenance within the microbial communities.展开更多
The performance of a biofilter relies on the activity of microorganisms during the gas contaminant treatment process. In this study, SO2 was treated using a laboratory-scale biofilter packed with polyurethane foam cu...The performance of a biofilter relies on the activity of microorganisms during the gas contaminant treatment process. In this study, SO2 was treated using a laboratory-scale biofilter packed with polyurethane foam cubes（PUFC）, on which thermophilic desulfurization bacteria were attached. The thermophilic biofilter effectively reduced SO2 within 10 months of operation time, with a maximum elimination capacity of 48.29 g/m^3/hr.Temporal shifts in the microbial population in the thermophilic biofilter were determined through polymerase chain reaction-denaturing gradient gel electrophoresis and deoxyribonucleic acid（DNA） sequence analysis. The substrate species and environmental conditions in the biofilter influenced the microbial population. Oxygen distribution in the PUFC was analyzed using a microelectrode. When the water-containing rate in PUFC was over 98%, the oxygen distribution presented aerobic–anoxic–aerobic states along the test route on the PUFC. The appearance of sulfate-reducing bacteria was caused by the anaerobic conditions and sulfate formation after 4 months of operation.展开更多
This study aimed to determine the characteristics of soil microbial community composition and its relationship with soil chemical properties during natural recovery in the Loess Plateau.The soil microbial community co...This study aimed to determine the characteristics of soil microbial community composition and its relationship with soil chemical properties during natural recovery in the Loess Plateau.The soil microbial community composition was analyzed by comparing the soil microbial phospholipid fatty acids（PLFAs） of eight croplands abandoned for 1,3,5,10,13,15,20,and 30 yr in the Dunshan watershed,northern Loess Plateau,China.The results showed that soil organic carbon,total nitrogen,soil microbial biomass carbon,and soil microbial biomass nitrogen significantly increased with the abandonment duration,whereas the metabolic quotient significantly decreased.The Shannon richness and Shannon evenness of PLFAs significantly increased after 10 yr of abandonment.Gram-negative,Gram-positive,bacterial,fungal,and total PLFAs linearly increased with increased abandonment duration.Redundancy analysis showed that the abandonment duration was the most important environmental factor in determining the PLFA microbial community composition.The soil microbial PLFAs changed from anteiso-to iso-,unsaturated to saturated,and short-to long-chain during natural recovery.Therefore,in the Loess Plateau,cropland abandonment for natural recovery resulted in the increase of the soil microbial PLFA biomass and microbial PLFA species and changed the microbial from chemolithotrophic to a more heterotrophic community.展开更多
This study investigated the use of microbial analysis as a bioremediation option for remediating petroleum sludge, which is part of the waste stream generated in the petroleum industry. The aim is to reduce environmen...This study investigated the use of microbial analysis as a bioremediation option for remediating petroleum sludge, which is part of the waste stream generated in the petroleum industry. The aim is to reduce environmental burden caused by the discharge of untreated sludge. Sludge sample was cultured in other to isolate microorganisms for the sludge treatment. The selected strain of the organisms after screening were Aspergillus flavus, Aspergillus niger, Verticillus sp, Penicillum sp, and Microsporium audouinii. Bioreactors (labeled A, B, C, D and O) were designed for the treatment of petroleum sludge. These reactors contain 2.0 × 10<sup>-2</sup> m<sup>3</sup> of the diluted sludge samples and the isolated organisms for the treatment process. On a weekly basis, the control reactors received 1.5 × 10<sup>-3</sup> m<sup>3</sup> of fresh and saline water respectively. After 12 weeks of treatment, sludge physicochemical characteristics showed distinct variations. From the result, reactor D was the best in terms of remediating the sludge as compared to other reactors. Friedman non-parametric test was performed to check if the weeks of treatment affected the reduction of the total hydrocarbon content (THC) in the five reactors and also checked for significant differences in the THC after treatments. The drop in the THC of the treated sludge ranged from 56.0% to 67.3%. These results showed the possibility of enhanced biodegradation of petroleum sludge by hydrocarbon utilizing microorganisms (fungi).展开更多
Date palm （Phoenix dactylifera L.） fruit is an important component in arid and semi-arid diet regions of the world. The present study pointed out microbial investigating of date palm collected from National wholesal...Date palm （Phoenix dactylifera L.） fruit is an important component in arid and semi-arid diet regions of the world. The present study pointed out microbial investigating of date palm collected from National wholesale market in Fez city in the center north of Morocco. The results reveal that samples dates studied are contaminated by bacteria such as TAMF （total aerobic mesophilic flora）, ASR （anaerobic sulfite reducing）, yeasts and molds. The percentage of yeasts isolated is 50% for Saccharomyces cervisae, 10% for Zygosaccharomyces fermentati, 20% for Hansenula anomala, 10% for Lodderomyces elongisporus and 10% for Kluyveromyces fragilis. The frequency of molds distribution is 51% for Aspergillus niger, 33% for Penicillium notatum and 16% for Rhizopus oryzae. Newman and keuls grouping test shows that fungal germs distribution is equal for yeast and molds in all samples analyzed. In the opposite bacterial grouping test shows greet difference between groups of bacteria isolated from date＇s samples.展开更多
Effective treatment of blackwater is critical for sustainable water management and environmental protection.This study investigated the performance of a novel two-stage anoxic-oxic moving bed biofilm reactor(A/O-MBBR)...Effective treatment of blackwater is critical for sustainable water management and environmental protection.This study investigated the performance of a novel two-stage anoxic-oxic moving bed biofilm reactor(A/O-MBBR)over an operational period of 82 d to enhance the treatment efficiency of blackwater.With an HRT of 25.5 h,the MBBR achieved removal rates of 94.4%for COD,99.7%for NH3-N,84.0%for TN,and 74.6%for TP.Even at reduced HRT,the system maintained consistently high removal efficiencies for both COD and TN,highlighting its robust performance under varying operational conditions.This study underscored the superior nitrification activity of attached biofilm compared to the suspended biomass.Predominant microbial genera identified within the biofilm included Thiothrix,Azospira,Acinetobacter,and Thauera genera,which played a critical role in nutrient removal processes.Notably,at low operational temperatures ranging from 8 to 15℃,facultative anaerobic species contributed significantly to sustaining nitrogen removal efficiencies,hence demonstrating the adaptability of the microbial community to varied environmental conditions.Furthermore,an advanced machine learning model,eXtreme Gradient Boosting(XGBoost),was developed and applied to predict pollutant concentrations across different A/O-MBBR chambers.The model exhibited exceptional predictive accuracy,highlighting the potential of integrating computational intelligence with biological treatment systems to optimize wastewater treatment processes.展开更多
Anaerobic digestion(AD)is a promising technology for the treatment of waste activated sludge(WAS)with energy recovery.However,the low methane yield and slow methanogenesis limit its broad application.In this study,the...Anaerobic digestion(AD)is a promising technology for the treatment of waste activated sludge(WAS)with energy recovery.However,the low methane yield and slow methanogenesis limit its broad application.In this study,the NiFe_(2)O_(4)nanoparticles(NPs)were fabricated and applied as a conductive material to enhance the AD via promoting the direct interspecies electron transfer(DIET).The crystal structure,specific surface area,morphology and elemental composition of the as-prepared NiFe_(2)O_(4)NPs were characterized by X-ray diffraction(XRD),Brunauer-Emmett-Teller(BET),scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).The biochemical methane potential(BMP)test was performed(lasting for 35 days)to evaluate the energy recovery in AD with the addition of the NiFe_(2)O_(4)NPs.The results illustrate that NiFe_(2)O_(4)NPs could accelerate both the hydrolysis,acidogenesis and methanogenesis,i.e.,the cumulative methane production and daily methane yield increased from 96.76±1.70 mL/gVS and 8.24±1.26 mL gVS^(-1)d^(-1)in the absence of NiFe_(2)O_(4)NPs(Group A)to 123.69±3.20 mL/gVS and 9.71±0.77 mL gVS^(-1)d^(-1)in the presence of NiFe_(2)O_(4)NPs(Group B).The model simulation results showed that both the first-order kinetic model and the modified Gompertz model can well simulate the experimental results.The hydrolysis rate constant k increased from 0.04±0.01 d^(-1)in Group A to 0.06±0.01 d^(-1)in Group B.And the maximum methane production potential and activity were both improved after adding NiFe_(2)O_(4).The microbial community analysis revealed that the microorganisms associated with hydrolysis and acidogenesis were more abundant in the presence of NiFe_(2)O_(4).And the methanogenic archaea were enriched to a larger extent,resulted in the higher methanogenesis activities via dosing NiFe_(2)O_(4).展开更多
Fe(Ⅱ)is an essential trace element for anaerobic ammonium oxidation bacteria(AAOB)metabolism,and can improve the nitrogen removal efficiency of anaerobic ammonia oxidation(Anammox).Here we oper-ated two identical exp...Fe(Ⅱ)is an essential trace element for anaerobic ammonium oxidation bacteria(AAOB)metabolism,and can improve the nitrogen removal efficiency of anaerobic ammonia oxidation(Anammox).Here we oper-ated two identical expanded granular sludge bed(EGSB)reactors at low temperature(15±3℃)for 154 days.Reactor 1(R_(1))received additional Fe(Ⅱ)(0.12 mmol/L)during the late startup phase,while reactor 0(R_(0))served as the control and did not receive extra Fe(Ⅱ).Nitrogen removal in R_(1)became stable at 55 d of operation,ten days earlier than R_(0).The nitrogen removal rate(NRR)of R_(1) was 1.64 kg N m^(−3)d^(−1)and its TN removal rate was as high as 89%,while R_(0)only reached 75%.The addition of Fe(Ⅱ)was fur-ther beneficial to aggregation and stability of the granular sludge,and the used sludge of both reactors showed enrichment for AAOB populations compared to the inoculum,for instance,increased abundance of Candidatus-Kuenenia and in particular of Candidatus-Brocadia(from 0.17%to 10.10%in R_(0)and 7.79%in R_(1)).Diverse microbial species and complex microbial network structure in R_(1)compared to R_(0)promoted the coupled denitrogenation by Anammox,dissimilatory nitrate reduction to ammonium(DNRA),nitrate-dependent Fe oxidation(NDFO),and ferric ammonium oxidation(Feammox).In addition,the microbial community in R_(1)was more resistant to short-term low temperature(2-7℃)starvation,illustrating a further positive effect of adding Fe(Ⅱ)during the startup phase of an Anammox reactor.展开更多
The hydrogen-producing consortium conveying the lactate-fermentation pathway was enriched and used as a coinoculum with the non-enriched hydrogen-producing consortium for biohydrogen production in the presence of lact...The hydrogen-producing consortium conveying the lactate-fermentation pathway was enriched and used as a coinoculum with the non-enriched hydrogen-producing consortium for biohydrogen production in the presence of lactic acid bacteria(LAB).The co-inoculum treatment achieved superior hydrogen production performance compared to that of the non-enriched consortium treatment.The effects of enriched consortium concentration,initial pH,and glucose concentration were evaluated,and hydrogen production potential(HP)of 1,605±161 mL-H_(2)/L and a maximum hydrogen production rate(HPR)of 87.17±15.85 mL-H_(2)/L.h were achieved under optimal conditions.Biohydrogen production from food waste using the co-inoculum was 1,137 mL-H_(2)/L from non-autoclaved food waste,corresponding to 56.85 mL-H_(2)/g-VS_(added).Metabolite product and microbial community analyses during food waste fermentation indicated positive cross-feeding activity of hydrogen producers,LAB,and acetogenic bacteria.This study provides valuable information on the use of an efficient,enriched hydrogen-producing consortium to improve biohydrogen production from LAB-contaminated feedstock.展开更多
A novel thermophilic two-ring bioreactor was employed to produce biohythane from palm oil mill effluent(POME)using Thermoanaerobacterium thermosaccharolyticum PSU-2 and thermophilic methanogenic mixed cul-tures.The re...A novel thermophilic two-ring bioreactor was employed to produce biohythane from palm oil mill effluent(POME)using Thermoanaerobacterium thermosaccharolyticum PSU-2 and thermophilic methanogenic mixed cul-tures.The reactor system demonstrated impressive performance,achieving hydrogen and methane yields of 113.3±15.0 mL/g-VS and 473.0±60.0 mL/g-VS,respectively,with a total biohythane composition of 4.3%H_(2),37.1%CO_(2),and 58.6%CH_(4).The process exhibited high treatment efficiency,with COD and VS removal efficiencies reaching 93.7% and 84.3%,respectively.Microbial community analysis revealed the crucial roles of various microorganisms in the biohythane production process.Thermoclostridium sp.,Thermoanaerobacterium sp.,and Anaerobranca sp.were identified as key players in hydrogen production,while Bacteroides sp.and Meth-anobacterium sp.were found to be essential for methane production.The optimization of operating conditions,including pH(5.0-8.0),temperature(55℃),and hydraulic retention time(2 d for H_(2) and 10 d for CH_(4)),significantly enhanced biohythane production efficiency.The techno-economic analysis demonstrated the eco-nomic viability of the thermophilic two-ring bioreactor system,with a net present value of 4,186,000 USD,an internal rate of return of 82%,and a payback period of 1.4 years.These findings highlight the potential of this innovative technology as a sustainable and economically attractive solution for treating POME and simulta-neously producing renewable energy in the form of biohythane,contributing to the sustainable development of the palm oil industry and the mitigation of greenhouse gas emissions.展开更多
The two-stage anaerobic digestion of palm oil mill effluent(POME)was optimized through trace metal sup-plementation(Mo^(2+),Ni^(2+),Co^(2+),and Fe^(2+)).Optimal concentrations were determined as 10 mg·L^(-1) Mo^(...The two-stage anaerobic digestion of palm oil mill effluent(POME)was optimized through trace metal sup-plementation(Mo^(2+),Ni^(2+),Co^(2+),and Fe^(2+)).Optimal concentrations were determined as 10 mg·L^(-1) Mo^(2+),6 mg·L^(-1) Ni^(2+),6 mg·L^(-1) Co^(2+),and 10 mg·L^(-1) Fe^(2+),resulting in significant biogas yield improvements on hydrogen yield increased by 86.4%(29.5±0.9 to 55.0±2.1 mL-H_(2)·g^(-1)-VS)and methane yield by 84%(from 173.8±7.8 to 320.0±8.4 mL-CH_(4)·g^(-1)-VS).Gas composition improved,with H_(2) content increasing from 18.5% to 32.0% and CH_(4) content from 58.2% to 72.5%.Maximum process efficiency was achieved at 4-day HRT for hydrogen production and 20-day HRT for methanogenesis with metal removal 0f 93.5-94.8%.Statistical analysis revealed strong correlations between metal concentrations and enzyme activities(R^(2)=0.94,p<0.001)and enzyme activities with biogas yields(R^(2)=0.92,p<0.001).Metabolite profiles showed an 81%increase in acetic acid(3,800±120 mg·L^(-1))and a 93% increase in butyric acid(2,900±95 mg·L^(-1)),while propionic acid decreased by 57% in H_(2) stage.Thermoanaerobacterium thermosaccharolyticum was dominant in the H_(2) stage,while Methanobacter sp.and Methanosarcina sp.dominated in the CH_(4) stage,with their abundance influenced by specific trace metal supplementation.Process stability was maintained through precise control systems(tem-perature stability index of 0.95±0.05 and pH stability index of 0.92±0.05)with rapid response times(<5 min).COD removal efficiency increased from 65.3% to 85.2%,while metal removal efficiencies exceeded 90% for all supplemented metals.These findings demonstrate significant enhancement in biogas production through optimized trace metal supplementation and precise process control strategies.展开更多
Background:Anorexia nervosa(AN)is a psychological disorder,which is characterized by the misunderstanding of body image,food restriction,and low body weight.An increasing number of studies have reported that the patho...Background:Anorexia nervosa(AN)is a psychological disorder,which is characterized by the misunderstanding of body image,food restriction,and low body weight.An increasing number of studies have reported that the pathophysiological mechanism of AN might be associated with the dysbiosis of gut microbiota.The purpose of our study was to explore the features of gut microbiota in patients with AN,hoping to provide valuable information on its pathogenesis and treatment.Methods:In this cross-sectional study,from August 2020 to June 2021,patients with AN who were admitted into Peking University Third Hospital and Peking University Sixth Hospital(n=30)were recruited as the AN group,and healthy controls(HC)were recruited from a middle school and a university in Beijing(n=30).Demographic data,Hamilton Depression Scale(HAMD)scores of the two groups,and length of stay of the AN group were recorded.Microbial diversity analysis of gut microbiota in stool samples from the two groups was analyzed by 16S ribosomal RNA(rRNA)gene sequencing.Results:The weight(AN vs.HC,[39.31±7.90]kg vs.[56.47±8.88]kg,P<0.001)and body mass index(BMI,AN vs.HC,[14.92±2.54]kg/m^(2)vs.[20.89±2.14]kg/m^(2),P<0.001)of patients with AN were statistically significantly lower than those of HC,and HAMD scores in AN group were statistically significantly higher than those of HC.For alpha diversity,there were no statistically significant differences between the two groups;for beta diversity,the two groups differed obviously regarding community composition.Compared to HC,the proportion of Lachnospiraceae in patients with AN was statistically significantly higher(AN vs.HC,40.50%vs.31.21%,Z=-1.981,P=0.048),while that of Ruminococcaceae was lower(AN vs.HC,12.17%vs.19.15%,Z=-2.728,P=0.007);the proportion of Faecalibacterium(AN vs.HC,3.97%vs.9.40%,Z=-3.638,P<0.001)and Subdoligranulum(AN vs.HC,4.60%vs.7.02%,Z=-2.369,P=0.018)were statistically significantly lower,while that of Eubacterium_halli_group was significantly higher(AN vs.HC,7.63%vs.3.43%,Z=-2.115,P=0.035).Linear discriminant effect(LEfSe)analysis(LDA score>3.5)showed that o_Lachnospirales,f_Lachnospiraceae,and g_Eubacterium_halli_group(o,f andg represents order,family and genus respectively)were enriched in patients with AN.Microbial function of nutrient transport and metabolism in AN group were more abundant(P>0.05).In AN group,weight and BMI were significantly negatively correlated with the abundance of Bacteroidota and Bacteroides,while positively correlated with Subdoligranulum.BMI was significantly positively correlated with Firmicutes;HAMD scores were significantly negatively correlated with Faecalibacterium.Conclusions:The composition of gut microbiota in patients with AN was different from that of healthy people.Clinical indicators have correlations with the abundance of gut microbiota in patients with AN.展开更多
Metallurgical wastewaters contain high concentrations of sulfate,up to 15 g L^(-1).Sulfate-reducing bioreactors are employed to treat these wastewaters,reducing sulfates to sulfides which subsequently coprecipitate me...Metallurgical wastewaters contain high concentrations of sulfate,up to 15 g L^(-1).Sulfate-reducing bioreactors are employed to treat these wastewaters,reducing sulfates to sulfides which subsequently coprecipitate metals.Sulfate loading and reduction rates are typically restricted by the total H2S concentration.Sulfide stripping,sulfide precipitation and dilution are the main strategies employed to minimize inhibition by H2S,but can be adversely compromised by suboptimal sulfate reduction,clogging and additional energy costs.Here,metallurgical wastewater was treated for over 250 days using two hydrogenotrophic granular activated carbon expanded bed bioreactors without additional removal of sulfides.H2S toxicity was minimized by operating at pH 8±0.15,resulting in an average sulfate removal of 7.08±0.08 g L^(-1),sulfide concentrations of 2.1±0.2 g L^(-1) and peaks up to 2.3±0.2 g L^(-1).A sulfate reduction rate of 20.6±0.9 g L^(-1)d^(-1) was achieved,with maxima up to 27.2 g L^(-1)d^(-1),which is among the highest reported considering a literature review of 39 studies.The rates reported here are 6e8 times higher than those reported for other reactors without active sulfide removal and the only reported for expanded bed sulfate-reducing bioreactors using H2.By increasing the influent sulfate concentration and maintaining high sulfide concentrations,sulfate reducers were promoted while fermenters and methanogens were suppressed.Industrial wastewater containing 4.4 g L^(-1) sulfate,0.036 g L^(-1) nitrate and various metals(As,Fe,Tl,Zn,Ni,Sb,Co and Cd)was successfully treated with all metal(loid)s,nitrates and sulfates removed below discharge limits.展开更多
基金supported by the National Key Research and Development Program of China (No. 2016YFC0502801)
文摘Effluents from wastewater treatment plants（WWTPs） containing microorganisms and residual nutrients can influence the biofilm formation. Although the process and mechanism of bacterial biofilm formation have been well characterized, little is known about the characteristics and interaction of bacteria, archaea and eukaryotes in the early colonization, especially under the influence of WWTP effluent. The aim of this study was to characterize the important bacterial, archaeal and eukaryotic species in the early stage of biofilm formation downstream of the WWTP outlet. Water and biofilm samples were collected 24 and 48 hr after the deposition of bio-cords in the stream. Illumina Miseq sequencing of the 16 S and 18 S rDNA showed that, among the three domains, the bacterial biofilm community had the largest alpha and beta diversity. The early bacterial colonizers appeared to be ＂biofilm-specific＂, with only a few dominant operational taxonomic units（OTUs） shared between the biofilm and the ambient water environment. Alpha-proteobacteria and Ciliophora tended to dominate the bacterial and eukaryotic communities, respectively, of the early biofilm already at 24 hr, whereas archaea played only a minor role during the early stage of colonization. The network analysis showed that the three domains of microbial community connected highly during the early colonization and it might be a characteristic of the microbial communities in the biofilm formation process where co-occurrence relationships could drive coexistence and diversity maintenance within the microbial communities.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment (No.2010ZX07319-001-03)the National Natural Science Foundation of China (No.51221892)
文摘The performance of a biofilter relies on the activity of microorganisms during the gas contaminant treatment process. In this study, SO2 was treated using a laboratory-scale biofilter packed with polyurethane foam cubes（PUFC）, on which thermophilic desulfurization bacteria were attached. The thermophilic biofilter effectively reduced SO2 within 10 months of operation time, with a maximum elimination capacity of 48.29 g/m^3/hr.Temporal shifts in the microbial population in the thermophilic biofilter were determined through polymerase chain reaction-denaturing gradient gel electrophoresis and deoxyribonucleic acid（DNA） sequence analysis. The substrate species and environmental conditions in the biofilter influenced the microbial population. Oxygen distribution in the PUFC was analyzed using a microelectrode. When the water-containing rate in PUFC was over 98%, the oxygen distribution presented aerobic–anoxic–aerobic states along the test route on the PUFC. The appearance of sulfate-reducing bacteria was caused by the anaerobic conditions and sulfate formation after 4 months of operation.
基金funded by the Strategic Technology Project of Chinese Academy of Sciences (XDA05060300)the Science and Technology Research and Development Program of Shaanxi Province, China (2011KJXX63)
文摘This study aimed to determine the characteristics of soil microbial community composition and its relationship with soil chemical properties during natural recovery in the Loess Plateau.The soil microbial community composition was analyzed by comparing the soil microbial phospholipid fatty acids（PLFAs） of eight croplands abandoned for 1,3,5,10,13,15,20,and 30 yr in the Dunshan watershed,northern Loess Plateau,China.The results showed that soil organic carbon,total nitrogen,soil microbial biomass carbon,and soil microbial biomass nitrogen significantly increased with the abandonment duration,whereas the metabolic quotient significantly decreased.The Shannon richness and Shannon evenness of PLFAs significantly increased after 10 yr of abandonment.Gram-negative,Gram-positive,bacterial,fungal,and total PLFAs linearly increased with increased abandonment duration.Redundancy analysis showed that the abandonment duration was the most important environmental factor in determining the PLFA microbial community composition.The soil microbial PLFAs changed from anteiso-to iso-,unsaturated to saturated,and short-to long-chain during natural recovery.Therefore,in the Loess Plateau,cropland abandonment for natural recovery resulted in the increase of the soil microbial PLFA biomass and microbial PLFA species and changed the microbial from chemolithotrophic to a more heterotrophic community.
文摘This study investigated the use of microbial analysis as a bioremediation option for remediating petroleum sludge, which is part of the waste stream generated in the petroleum industry. The aim is to reduce environmental burden caused by the discharge of untreated sludge. Sludge sample was cultured in other to isolate microorganisms for the sludge treatment. The selected strain of the organisms after screening were Aspergillus flavus, Aspergillus niger, Verticillus sp, Penicillum sp, and Microsporium audouinii. Bioreactors (labeled A, B, C, D and O) were designed for the treatment of petroleum sludge. These reactors contain 2.0 × 10<sup>-2</sup> m<sup>3</sup> of the diluted sludge samples and the isolated organisms for the treatment process. On a weekly basis, the control reactors received 1.5 × 10<sup>-3</sup> m<sup>3</sup> of fresh and saline water respectively. After 12 weeks of treatment, sludge physicochemical characteristics showed distinct variations. From the result, reactor D was the best in terms of remediating the sludge as compared to other reactors. Friedman non-parametric test was performed to check if the weeks of treatment affected the reduction of the total hydrocarbon content (THC) in the five reactors and also checked for significant differences in the THC after treatments. The drop in the THC of the treated sludge ranged from 56.0% to 67.3%. These results showed the possibility of enhanced biodegradation of petroleum sludge by hydrocarbon utilizing microorganisms (fungi).
文摘Date palm （Phoenix dactylifera L.） fruit is an important component in arid and semi-arid diet regions of the world. The present study pointed out microbial investigating of date palm collected from National wholesale market in Fez city in the center north of Morocco. The results reveal that samples dates studied are contaminated by bacteria such as TAMF （total aerobic mesophilic flora）, ASR （anaerobic sulfite reducing）, yeasts and molds. The percentage of yeasts isolated is 50% for Saccharomyces cervisae, 10% for Zygosaccharomyces fermentati, 20% for Hansenula anomala, 10% for Lodderomyces elongisporus and 10% for Kluyveromyces fragilis. The frequency of molds distribution is 51% for Aspergillus niger, 33% for Penicillium notatum and 16% for Rhizopus oryzae. Newman and keuls grouping test shows that fungal germs distribution is equal for yeast and molds in all samples analyzed. In the opposite bacterial grouping test shows greet difference between groups of bacteria isolated from date＇s samples.
基金supported by National Key R&D program of China(No.2022YFD1601000)Sino-German Cooperation 2.0 Strategic Support Program Project of Tongji University,China(No.ZD2023002).
文摘Effective treatment of blackwater is critical for sustainable water management and environmental protection.This study investigated the performance of a novel two-stage anoxic-oxic moving bed biofilm reactor(A/O-MBBR)over an operational period of 82 d to enhance the treatment efficiency of blackwater.With an HRT of 25.5 h,the MBBR achieved removal rates of 94.4%for COD,99.7%for NH3-N,84.0%for TN,and 74.6%for TP.Even at reduced HRT,the system maintained consistently high removal efficiencies for both COD and TN,highlighting its robust performance under varying operational conditions.This study underscored the superior nitrification activity of attached biofilm compared to the suspended biomass.Predominant microbial genera identified within the biofilm included Thiothrix,Azospira,Acinetobacter,and Thauera genera,which played a critical role in nutrient removal processes.Notably,at low operational temperatures ranging from 8 to 15℃,facultative anaerobic species contributed significantly to sustaining nitrogen removal efficiencies,hence demonstrating the adaptability of the microbial community to varied environmental conditions.Furthermore,an advanced machine learning model,eXtreme Gradient Boosting(XGBoost),was developed and applied to predict pollutant concentrations across different A/O-MBBR chambers.The model exhibited exceptional predictive accuracy,highlighting the potential of integrating computational intelligence with biological treatment systems to optimize wastewater treatment processes.
基金financially supported by the Fundamental Research Funds for Central Universities(Nos.3102019AX18 and 310201911cx021)the Specialized Fund for the Post-Disaster Reconstruction and Heritage Project ion in Sichuan Province(No.5132202019000128)。
文摘Anaerobic digestion(AD)is a promising technology for the treatment of waste activated sludge(WAS)with energy recovery.However,the low methane yield and slow methanogenesis limit its broad application.In this study,the NiFe_(2)O_(4)nanoparticles(NPs)were fabricated and applied as a conductive material to enhance the AD via promoting the direct interspecies electron transfer(DIET).The crystal structure,specific surface area,morphology and elemental composition of the as-prepared NiFe_(2)O_(4)NPs were characterized by X-ray diffraction(XRD),Brunauer-Emmett-Teller(BET),scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).The biochemical methane potential(BMP)test was performed(lasting for 35 days)to evaluate the energy recovery in AD with the addition of the NiFe_(2)O_(4)NPs.The results illustrate that NiFe_(2)O_(4)NPs could accelerate both the hydrolysis,acidogenesis and methanogenesis,i.e.,the cumulative methane production and daily methane yield increased from 96.76±1.70 mL/gVS and 8.24±1.26 mL gVS^(-1)d^(-1)in the absence of NiFe_(2)O_(4)NPs(Group A)to 123.69±3.20 mL/gVS and 9.71±0.77 mL gVS^(-1)d^(-1)in the presence of NiFe_(2)O_(4)NPs(Group B).The model simulation results showed that both the first-order kinetic model and the modified Gompertz model can well simulate the experimental results.The hydrolysis rate constant k increased from 0.04±0.01 d^(-1)in Group A to 0.06±0.01 d^(-1)in Group B.And the maximum methane production potential and activity were both improved after adding NiFe_(2)O_(4).The microbial community analysis revealed that the microorganisms associated with hydrolysis and acidogenesis were more abundant in the presence of NiFe_(2)O_(4).And the methanogenic archaea were enriched to a larger extent,resulted in the higher methanogenesis activities via dosing NiFe_(2)O_(4).
基金supported by the State Key Laboratory of Geo-hazard Prevention and Geoenvironment Protection Foundation(No.SKLGP2022Z012)the National Natural Science Foundation of China(No.41502333).
文摘Fe(Ⅱ)is an essential trace element for anaerobic ammonium oxidation bacteria(AAOB)metabolism,and can improve the nitrogen removal efficiency of anaerobic ammonia oxidation(Anammox).Here we oper-ated two identical expanded granular sludge bed(EGSB)reactors at low temperature(15±3℃)for 154 days.Reactor 1(R_(1))received additional Fe(Ⅱ)(0.12 mmol/L)during the late startup phase,while reactor 0(R_(0))served as the control and did not receive extra Fe(Ⅱ).Nitrogen removal in R_(1)became stable at 55 d of operation,ten days earlier than R_(0).The nitrogen removal rate(NRR)of R_(1) was 1.64 kg N m^(−3)d^(−1)and its TN removal rate was as high as 89%,while R_(0)only reached 75%.The addition of Fe(Ⅱ)was fur-ther beneficial to aggregation and stability of the granular sludge,and the used sludge of both reactors showed enrichment for AAOB populations compared to the inoculum,for instance,increased abundance of Candidatus-Kuenenia and in particular of Candidatus-Brocadia(from 0.17%to 10.10%in R_(0)and 7.79%in R_(1)).Diverse microbial species and complex microbial network structure in R_(1)compared to R_(0)promoted the coupled denitrogenation by Anammox,dissimilatory nitrate reduction to ammonium(DNRA),nitrate-dependent Fe oxidation(NDFO),and ferric ammonium oxidation(Feammox).In addition,the microbial community in R_(1)was more resistant to short-term low temperature(2-7℃)starvation,illustrating a further positive effect of adding Fe(Ⅱ)during the startup phase of an Anammox reactor.
基金funded by the Fundamental Fund of Khon Kaen University from the National Science,Research and Innovation Fund(NSRF)the Research Group for Development of Microbial Hydrogen Production Process from Biomass,Khon Kaen University,Thailand.
文摘The hydrogen-producing consortium conveying the lactate-fermentation pathway was enriched and used as a coinoculum with the non-enriched hydrogen-producing consortium for biohydrogen production in the presence of lactic acid bacteria(LAB).The co-inoculum treatment achieved superior hydrogen production performance compared to that of the non-enriched consortium treatment.The effects of enriched consortium concentration,initial pH,and glucose concentration were evaluated,and hydrogen production potential(HP)of 1,605±161 mL-H_(2)/L and a maximum hydrogen production rate(HPR)of 87.17±15.85 mL-H_(2)/L.h were achieved under optimal conditions.Biohydrogen production from food waste using the co-inoculum was 1,137 mL-H_(2)/L from non-autoclaved food waste,corresponding to 56.85 mL-H_(2)/g-VS_(added).Metabolite product and microbial community analyses during food waste fermentation indicated positive cross-feeding activity of hydrogen producers,LAB,and acetogenic bacteria.This study provides valuable information on the use of an efficient,enriched hydrogen-producing consortium to improve biohydrogen production from LAB-contaminated feedstock.
基金the Royal Golden Jubilee Ph.D.Grant[2.B.TK/60/A.1]the National Research Council of Thailand(NRCT)through the Talented Mid-Career Research Grant(Grant No.N41A640088the Graduate Education Development Fund for the Fiscal Year 2021 for their generous financial support,which made this research possible.
文摘A novel thermophilic two-ring bioreactor was employed to produce biohythane from palm oil mill effluent(POME)using Thermoanaerobacterium thermosaccharolyticum PSU-2 and thermophilic methanogenic mixed cul-tures.The reactor system demonstrated impressive performance,achieving hydrogen and methane yields of 113.3±15.0 mL/g-VS and 473.0±60.0 mL/g-VS,respectively,with a total biohythane composition of 4.3%H_(2),37.1%CO_(2),and 58.6%CH_(4).The process exhibited high treatment efficiency,with COD and VS removal efficiencies reaching 93.7% and 84.3%,respectively.Microbial community analysis revealed the crucial roles of various microorganisms in the biohythane production process.Thermoclostridium sp.,Thermoanaerobacterium sp.,and Anaerobranca sp.were identified as key players in hydrogen production,while Bacteroides sp.and Meth-anobacterium sp.were found to be essential for methane production.The optimization of operating conditions,including pH(5.0-8.0),temperature(55℃),and hydraulic retention time(2 d for H_(2) and 10 d for CH_(4)),significantly enhanced biohythane production efficiency.The techno-economic analysis demonstrated the eco-nomic viability of the thermophilic two-ring bioreactor system,with a net present value of 4,186,000 USD,an internal rate of return of 82%,and a payback period of 1.4 years.These findings highlight the potential of this innovative technology as a sustainable and economically attractive solution for treating POME and simulta-neously producing renewable energy in the form of biohythane,contributing to the sustainable development of the palm oil industry and the mitigation of greenhouse gas emissions.
基金the financial support provided by the National Science and Research Fund(NSRF)through the Program Management Unit for Human Resources&Institutional Development,Research and Innovation(grant number B13F660062)the National Research Council of Thailand(NRCT)for their support through the Talented Mid-Career Research Grant(Grant No.N41A640088)+1 种基金The Royal Golden Jubilee Ph.D provided additional funding.Grant[2.B.TK/60/A.1]the Graduate Education Development Fund for the Fiscal Year 2021.
文摘The two-stage anaerobic digestion of palm oil mill effluent(POME)was optimized through trace metal sup-plementation(Mo^(2+),Ni^(2+),Co^(2+),and Fe^(2+)).Optimal concentrations were determined as 10 mg·L^(-1) Mo^(2+),6 mg·L^(-1) Ni^(2+),6 mg·L^(-1) Co^(2+),and 10 mg·L^(-1) Fe^(2+),resulting in significant biogas yield improvements on hydrogen yield increased by 86.4%(29.5±0.9 to 55.0±2.1 mL-H_(2)·g^(-1)-VS)and methane yield by 84%(from 173.8±7.8 to 320.0±8.4 mL-CH_(4)·g^(-1)-VS).Gas composition improved,with H_(2) content increasing from 18.5% to 32.0% and CH_(4) content from 58.2% to 72.5%.Maximum process efficiency was achieved at 4-day HRT for hydrogen production and 20-day HRT for methanogenesis with metal removal 0f 93.5-94.8%.Statistical analysis revealed strong correlations between metal concentrations and enzyme activities(R^(2)=0.94,p<0.001)and enzyme activities with biogas yields(R^(2)=0.92,p<0.001).Metabolite profiles showed an 81%increase in acetic acid(3,800±120 mg·L^(-1))and a 93% increase in butyric acid(2,900±95 mg·L^(-1)),while propionic acid decreased by 57% in H_(2) stage.Thermoanaerobacterium thermosaccharolyticum was dominant in the H_(2) stage,while Methanobacter sp.and Methanosarcina sp.dominated in the CH_(4) stage,with their abundance influenced by specific trace metal supplementation.Process stability was maintained through precise control systems(tem-perature stability index of 0.95±0.05 and pH stability index of 0.92±0.05)with rapid response times(<5 min).COD removal efficiency increased from 65.3% to 85.2%,while metal removal efficiencies exceeded 90% for all supplemented metals.These findings demonstrate significant enhancement in biogas production through optimized trace metal supplementation and precise process control strategies.
基金funded by the Cross Seed Fund of Peking University(No.A74479-01).
文摘Background:Anorexia nervosa(AN)is a psychological disorder,which is characterized by the misunderstanding of body image,food restriction,and low body weight.An increasing number of studies have reported that the pathophysiological mechanism of AN might be associated with the dysbiosis of gut microbiota.The purpose of our study was to explore the features of gut microbiota in patients with AN,hoping to provide valuable information on its pathogenesis and treatment.Methods:In this cross-sectional study,from August 2020 to June 2021,patients with AN who were admitted into Peking University Third Hospital and Peking University Sixth Hospital(n=30)were recruited as the AN group,and healthy controls(HC)were recruited from a middle school and a university in Beijing(n=30).Demographic data,Hamilton Depression Scale(HAMD)scores of the two groups,and length of stay of the AN group were recorded.Microbial diversity analysis of gut microbiota in stool samples from the two groups was analyzed by 16S ribosomal RNA(rRNA)gene sequencing.Results:The weight(AN vs.HC,[39.31±7.90]kg vs.[56.47±8.88]kg,P<0.001)and body mass index(BMI,AN vs.HC,[14.92±2.54]kg/m^(2)vs.[20.89±2.14]kg/m^(2),P<0.001)of patients with AN were statistically significantly lower than those of HC,and HAMD scores in AN group were statistically significantly higher than those of HC.For alpha diversity,there were no statistically significant differences between the two groups;for beta diversity,the two groups differed obviously regarding community composition.Compared to HC,the proportion of Lachnospiraceae in patients with AN was statistically significantly higher(AN vs.HC,40.50%vs.31.21%,Z=-1.981,P=0.048),while that of Ruminococcaceae was lower(AN vs.HC,12.17%vs.19.15%,Z=-2.728,P=0.007);the proportion of Faecalibacterium(AN vs.HC,3.97%vs.9.40%,Z=-3.638,P<0.001)and Subdoligranulum(AN vs.HC,4.60%vs.7.02%,Z=-2.369,P=0.018)were statistically significantly lower,while that of Eubacterium_halli_group was significantly higher(AN vs.HC,7.63%vs.3.43%,Z=-2.115,P=0.035).Linear discriminant effect(LEfSe)analysis(LDA score>3.5)showed that o_Lachnospirales,f_Lachnospiraceae,and g_Eubacterium_halli_group(o,f andg represents order,family and genus respectively)were enriched in patients with AN.Microbial function of nutrient transport and metabolism in AN group were more abundant(P>0.05).In AN group,weight and BMI were significantly negatively correlated with the abundance of Bacteroidota and Bacteroides,while positively correlated with Subdoligranulum.BMI was significantly positively correlated with Firmicutes;HAMD scores were significantly negatively correlated with Faecalibacterium.Conclusions:The composition of gut microbiota in patients with AN was different from that of healthy people.Clinical indicators have correlations with the abundance of gut microbiota in patients with AN.
基金This research was supported by Flanders Innovation&Entrepreneurship(VLAIO,HBC.217.000)the Research&Development Umicore Group.JVL is supported by Ghent University Bijzonder Onderzoeksfonds(BOF)BOF.GOA.2015.0002.01 and BOF15/GOA/006,while KF is supported by BOF/PDO/2020/0020+1 种基金KR is supported by a BOF GOA grant(BOF19/GOA/026)LB is supported by Ghent University Bijzonder Onderzoeksfonds BOF20/PDO/025.
文摘Metallurgical wastewaters contain high concentrations of sulfate,up to 15 g L^(-1).Sulfate-reducing bioreactors are employed to treat these wastewaters,reducing sulfates to sulfides which subsequently coprecipitate metals.Sulfate loading and reduction rates are typically restricted by the total H2S concentration.Sulfide stripping,sulfide precipitation and dilution are the main strategies employed to minimize inhibition by H2S,but can be adversely compromised by suboptimal sulfate reduction,clogging and additional energy costs.Here,metallurgical wastewater was treated for over 250 days using two hydrogenotrophic granular activated carbon expanded bed bioreactors without additional removal of sulfides.H2S toxicity was minimized by operating at pH 8±0.15,resulting in an average sulfate removal of 7.08±0.08 g L^(-1),sulfide concentrations of 2.1±0.2 g L^(-1) and peaks up to 2.3±0.2 g L^(-1).A sulfate reduction rate of 20.6±0.9 g L^(-1)d^(-1) was achieved,with maxima up to 27.2 g L^(-1)d^(-1),which is among the highest reported considering a literature review of 39 studies.The rates reported here are 6e8 times higher than those reported for other reactors without active sulfide removal and the only reported for expanded bed sulfate-reducing bioreactors using H2.By increasing the influent sulfate concentration and maintaining high sulfide concentrations,sulfate reducers were promoted while fermenters and methanogens were suppressed.Industrial wastewater containing 4.4 g L^(-1) sulfate,0.036 g L^(-1) nitrate and various metals(As,Fe,Tl,Zn,Ni,Sb,Co and Cd)was successfully treated with all metal(loid)s,nitrates and sulfates removed below discharge limits.
