Engineering
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2025
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IF 11.6
Wenyue Yan,Baogang Zhang,Yi’na Li,Jianping Lu,Yangmei Fei,Shungui Zhou,Hailiang Dong,Fang Huang
Microbial vanadate (V(V)) reduction is a key process for environmental geochemistry and detoxification of vanadium (V). However, the electron transfer pathways and V isotope fractionation involved in this process are not yet fully understood. In this study, the V(V) reduction mechanisms with concomitant V isotope fractionation by the gram-positive bacterium Bacillus subtilis ( B. subtilis ) and the gram-negative bacterium Thauera humireducens ( T. humireducens ) were investigated. Both strains could effectively reduce V(V), and (90.5% ± 1.6%) and (93.0% ± 1.8%) of V(V) at an initial concentration of 50 mg·L −1 was removed over 10 d incubation, respectively. V(V) was bioreduced to insoluble vanadium (IV), which was distributed both inside and outside the cells. Electron transfer via cytochrome C, nicotinamide adenine dinucleotide, and glutathione played critical roles in V(V) reduction. Metabolomic analysis showed that differentially enriched metabolites (quinone, biotin, and riboflavin) mediated electron transfer in both strains. The aqueous V in the remaining solution became isotopically heavier as V(V) bioreduction proceeded. The obtained V isotope composition dynamics followed a Rayleigh fractionation model, and the isotope enrichment factor ( ε ) was (–0.54‰ ± 0.04‰) for B. subtilis and (–0.32‰ ± 0.03‰) for T. humireducens , with an insignificant difference. This study provides molecular insights into electron transfer for V(V) bioreduction and reveals V isotope fractionation during this bioprocess, which is helpful for understanding V biogeochemistry and developing novel strategies for V remediation.
研究领域:
环境微生物学
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地球化学
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生物化学
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DOI
高影响因子
Scientific Reports
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2017
·Vol. 7
·期 1
·1-10
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IF 4.259
Dong Shanshan,Li Mu,Chen Yinguang
Microbial denitrification is the main pathway for nitrogen removal of landfill leachate. Although humic substances (HSs) have been reported in landfill leachate, the effects of HS on denitrification process of activated sludge for leachate treatment are still unknown. In this study, we adopted SAHA as the model HS to study the effects of HS on the denitrification of landfill leachate. After long-term operation at 10 mg/L of Shanghai Aladdin Humic Acid (SAHA), the final nitrate concentration and nitrite accumulation were much lower than the control (5.2 versus 96.2 mg/L; 0.5 versus 34.7 mg/L), and the final N 2 O emission was 13.1% of the control. The mechanistic study unveiled that SAHA substantially changed the activated sludge community structure and resulted in the dominance of Thauera after long-term exposure to SAHA. Thauera could be able to utilize HSs as electron shuttle to improve denitrificattion performance, especially for nitrite reduction. Moreover, SAHA significantly upregulated the gene expressions and catalytic activities of the key enzymes related to denitrification, the reducing power (NADH) generation, and the electron transport system activity, which accelerated nitrogen oxide reduction. The positive effects of HS on denitrification performance were confirmed by the addition of SAHA into real leachate.
研究领域:
环境科学
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微生物学
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废物管理
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DOI
PubMed
高影响因子
CHEMOSPHERE
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2021
·
IF 7.086
Binghan Xie,Heng Liang,Hong You,Shihai Deng,Zhongsen Yan,Xiaobin Tang
Though sulfamethoxazole (SMX) degradation at the low or medium concentration (SMX< 30 mg/L) has been reported in the microbial fuel cell (MFC), further exploration is still urgently required to investigate how the high concentration of SMX affect the anode biofilm formation. In this study, the degradation mechanism of SMX and the response of microbial community to SMX at different initial concentrations (0, 0.5, 5 and 50 mg/L) were investigated in MFCs. The highest SMX removal efficiency of 98.4% was obtained in MFC (5 mg/L). SMX at optimal concentration (5 mg/L) could serve as substrate accelerating the extracellular electron transfer . However, high concentration of SMX (50 mg/L) conferred significant inhibition on the electron transfer with SMX removal decline to 84.4%. The 16S rRNA high-throughput sequencing revealed the significant shift of the anode biofilms communities with different initial SMX concentrations were observed in MFCs. Thauera and Geobacter were the predominant genus, with relative abundance of 31.9% in MFC (50 mg/L SMX) and 52.7% in MFC (5 mg/L SMX). Methylophilus exhibited a huge increase with the highest percentage of 16.4% in MFC (50 mg/L). Hence, the functional bacteria of Thauera , Geobacter and Methylophilus endowed significant tolerance to the selection pressure from high concentration of SMX in MFCs. Meanwhile, some bacteria including Ornatilinea , Dechloromonas and Longilinea exhibited a decrease or even disappeared in MFCs. Therefore, initial concentrations of SMX played a fundamental role in modifying the relative abundance of predominant populations. This finding would promote theories support for understanding the evolution of anode biofilm formation related to the different initial concentrations of SMX in MFCs.
研究领域:
环境工程
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微生物学
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生物技术
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2020
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IF 9.038
Zhi-Ling Li,Rui Cheng,Fan Chen,Xiao-Qiu Lin,Xiao-Jing Yao,Bin Liang,Cong Huang,Kai Sun,Ai-Jie Wang
Antibiotics commonly exist in municipal, livestock and industrial wastewaters . However, the response of key microbiota performance in wastewater treatment plants to antibiotic exposure lacks systematic research. In this study, the short-term acute stress of four commonly used antibiotics (sulfamethoxazole, chlortetracycline, ciprofloxacin, and amoxicillin) on microbial denitrification performance was systematically investigated. All tested antibiotics exhibited the inhibitory effects in varying degrees by repeated addition for six cycles. The nitrate removal efficiencies ( NrE ) decreased to 7.98–26.80%, accompanied by the significant decrease of the expressed nar G gene, by exposure to sulfamethoxazole, chlortetracycline or amoxicillin. Nitrite reduction was inhibited more severely than nitrate reduction , which was further verified by the low- or non-expressed nir S and nos Z genes. Furthermore, a higher antibiotic concentration made stronger inhibitory effect. Except for chlortetracycline, 2.09–6.80 times decrease of k value was commonly observed as concentration increased from 10 to 50 or 100 mg L −1 . Even in a short period (24 h), antibiotics largely decreased the abundance of the dominant denitrifying bacterial genera ( Thauera , Comamonas , etc.), while, some unclassified populations ( Labrenzia , Longilinea, etc.) were enriched. This study provides theoretical researches on the microbial denitrification behaviors influenced by exposure to different antibiotics.
研究领域:
环境微生物学
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废水处理
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生态毒理学
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产品关联
DOI
PubMed
高影响因子
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