CHEMOSPHERE
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2021
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IF 7.086
Meiling Yi,Lilan Zhang,Cunli Qin,Peili Lu,Hongcheng Bai,Xinkuan Han,Shupei Yuan
Phenanthrene (PHE) is frequently detected in worldwide soils. But it is still not clear that how the microbial community succession happens and the nitrogen-cycling processes alter during PHE degradation. In this study, the temporal changes of soil microbial community composition and nitrogen-cycling processes during the biodegradation of PHE (12 μg g −1 ) were explored. The results showed that the biodegradation of PHE followed the second-order kinetics with a half-life of 7 days. QPCR results demonstrated that the bacteria numbers increased by 67.1%–194.7% with PHE degradation, whereas, no significant change was observed in fungi numbers. Thus, high-throughput sequencing based on 16 S rRNA was conducted and showed that the abundances of Methylotenera , Comamonadaceae , and Nocardioides involved in PHE degradation and denitrification were significantly increased, while those of nitrogen-metabolism-related genera such as Nitrososphaeraceae , Nitrospira , Gemmatimonadacea were decreased in PHE-treated soil. Co-occurrence network analysis suggested that more complex interrelations were constructed, and Proteobacteria instead of Acidobacteriota formed intimate associations with other microbes in responding to PHE exposure. Additionally, the abundances of nif H and nar G were significantly up-regulated in PHE-treated soil, while that of amo A especially AOA amo A was down-regulated. Finally, correlation analysis found several potential microbes ( Methylotenera , Comamonadaceae , and Agromyces ) that could couple PHE degradation and nitrogen transformation. This study confirmed that PHE could alter microbial community structure, change the native bacterial network, and disturb nitrogen-cycling processes.
研究领域:
环境微生物学
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土壤科学
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生物修复
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微生物生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2023
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IF 9.8
Wantong Zhang,Xiuping Tao,Zhengyi Hu,Enze Kang,Zhongqing Yan,Xiaodong Zhang,Jinzhi Wang
Alpine peatlands are recognized as a weak or negligible source of nitrous oxide (N 2 O). Anthropogenic activities and climate change resulted in the altered water table (WT) levels and increased nitrogen (N) deposition, which could potentially transition this habitat into a N 2 O emission hotspot. However, the underlying mechanism related with the effects is still uncertain. Hence, we conducted a mesocosm experiment to address the response of growing-season N 2 O emissions and the gene abundances of nitrification (bacterial amoA ) and denitrification ( narG , nirS , norB and nosZ ) to the increased N deposition (20 kg N ha −1 yr −1 ) at two WT levels (WT − 30 , 30 cm below soil surface; WT 10 , 10 cm above soil surface) in the Zoige alpine peatland, Qinghai-Tibetan Plateau. The results showed that the WT did not affect N 2 O emissions, and this was attributed with the limitation of soil NO 3 − . The higher WT level increased denitrification ( narG and nirS gene abundance) resulting in the depletion of soil NO 3 − , but the consequent NO 3 − deficiency further limited denitrification, while the WT did not affect nitrification (bacterial amoA gene abundance). Meanwhile, the N deposition increased N 2 O emissions, regardless of WT levels. This was associated with the N-deposition induced increase in denitrification-related gene abundances of narG , nirS , norB and nosZ at WT − 30 and narG at WT 10 . Additionally, the N 2 O emission factor assigned to N deposition was 1.3 % at WT − 30 and 0.9 % at WT 10 , respectively. Our study provided comprehensive understanding of the mechanisms referring N 2 O emissions in response to the interactions between climate change and human disturbance from this high-altitude peatland.
研究领域:
环境科学
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生态学
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微生物生态学
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气候变化
✓ 已验证
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
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2020
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IF 7.632
Zhen Bi,Wenjing Zhang,Min Ni,Ge Song,Yong Huang
The anammox bacteria (AnAOB) have been suggested to perform dissimilatory Fe0/Fe2+-dependent nitrate reduction to ammonium (DNRA), with nitrite as intermediate. However, evidence at genetic and transcriptional levels for how AnAOB reduces nitrate is still lacking, making their roles in this process obscure and questionable. The short-term batch assays and long-term operation of bioreactor combined with 16S rDNA sequencing and transcription analysis were used for the first time to investigate the nitrate reduction pathway in anammox consortia. It is shown that AnAOB metabolically well grew with nitrate as the sole nitrogen source. They reduced nitrate to nitrite with highly expressed narG gene. However, the DNRA-enabling gene nrfA was not expressed by AnAOB. Abiotic reduction by Fe0/Fe2+ contributed to the nitrate and nitrite reduction to ammonium. The correlation analysis of microbial community structure and metabolic functions indicated that amino acid and carbohydrate transport and metabolism interactions in coexisting bacteria could facilitate the AnAOB growth with nitrate as the only nitrogen source. Our findings suggest that the contribution of enzymatic DNRA by AnAOB to the observed nitrate reduction has been probably overestimated in previous publications, and it should be questioned until the clear enzymatic mechanism responsible for nitrate reduction is identified.
研究领域:
微生物学
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环境科学
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生物技术
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL RESEARCH
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2021
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IF 6.498
Zhi-Ling Li,Di Cao,Cai-Hua Bai,Xiao-Jing Yao,Xiao-Qiu Lin,Si-Pei Wang,Jun Nan,Bin Liang,Li-Wei Li,Kai Sun,Ai-Jie Wang
The response of the denitrification community to long-term antibiotic exposure requires further investigation. Here, the significantly altered denitrifying community structure and function were observed by continuous exposure to 1 mg/L sulfamethoxazole (SMZ) or chlortetracycline (CTC) for 180 d in the expanded granular sludge bed reactors. Thaurea , positively correlated with SMZ and NO 3 − removal efficiency ( NrE ), was highly enriched in the SMZ-added reactor, while, Comamons and Acinetobacter were largely inhibited. The acute inhibited and then gradual-recovered NrE (87.17–90.38 %) was observed with highly expressed narG , indicating the adaptability of Thaurea to SMZ. However, the abundance of Thaurea and Comamonas greatly decreased, while Melioribacter and Acinetobacter were largely enriched in the CTC-added reactor. CTC created more serious and continuous inhibition of NO 3 − reduction ( NrE of 64.53–66.95 %), with lowly expressed narG . Improved NO 2 − reduction capacity was observed in both reactors (70.16–95.42 %) with highly expressed nirS and nosZ , revealing the adaptability of NO 2 − reduction populations to antibiotics.
研究领域:
环境微生物学
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生物技术
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污水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2024
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IF 8.2
Yixing Zhang,Xueran Lin,Tang Xia,Hang Chen,Fu Huang,Chaohai Wei,Guanglei Qiu
The increased use of disinfection since the pandemic has led to increased effective chlorine concentration in municipal wastewater. Whereas, the specific impacts of active chlorine on nitrogen and phosphorus removal, the mediating communities, and the related metabolic activities in wastewater treatment plants (WWTPs) lack systematic investigation. We systematically analyzed the influences of chlorine disinfection on nitrogen and phosphorus removal activities using activated sludge from five full-scale WWTPs. Results showed that at an active chlorine concentration of 1.0 mg/g-SS, the nitrogen and phosphorus removal systems were not significantly affected. Major effects were observed at 5.0 mg/g-SS, where the nitrogen and phosphorus removal efficiency decreased by 38.9 % and 44.1 %, respectively. At an active chlorine concentration of 10.0 mg/g-SS, the nitrification, denitrification, phosphorus release and uptake activities decreased by 15.1 %, 69.5–95.9 %, 49.6 % and 100 %, respectively. The proportion of dead cells increased by 6.1 folds. Reverse transcriptional quantitative polymerase chain reaction (RT-qPCR) analysis showed remarkable inhibitions on transcriptions of the nitrite oxidoreductase gene ( nxr B), the nitrite reductase genes ( nir S and nir K), and the nitrite reductase genes ( nar G). The nitrogen and phosphorus removal activities completely disappeared with an active chlorine concentration of 25.0 mg/g-SS. Results also showed distinct sensitivities of different functional bacteria in the activated sludge. Even different species within the same functional group differ in their susceptibility. This study provides a reference for the understanding of the threshold active chlorine concentration values which may potentially affect biological nitrogen and phosphorus removal in full-scale WWTPs, which are expected to be beneficial for decision-making in WWTPs to counteract the potential impacts of increased active chlorine concentrations in the influent wastewater.
研究领域:
环境工程
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污水处理
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微生物学
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生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）