ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2018
·Vol. 25
·期 27
·27274-27282
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IF 2.8
Luo Jingyang,Zhang Qin,Wu Lijuan,Cao Jiashun,Feng Qian,Fang Fang,Chen Yinguang
1,4-Dioxane is an emerging pollutant, which widely exists in natural environments and poses potential risks to the living organisms. However, its effect on the denitrification process is still unknown. In this study, the effects of 1,4-dioxane on the denitrification process were therefore investigated by using Paracoccus denitrificans as the model denitrifier. The obtained results showed that the exposure of 1,4-dioxane exhibited remarkable lag or inhibition on the denitrification process, especially with high dose. In the control without 1,4-dioxane exposure, Paracoccus denitrificans showed high denitrification efficiency (98.5%). However, the efficiency decreased to 78.5, 63.9, and 9.3% with 0.50, 0.75, and 1.0% ( v / v ) 1,4-dioxane dose, respectively. The dose-induced inhibition of denitrification by 1,4-dioxane could be partially attributed to the negative effects on proliferation and viability of functional microorganisms by conjugating and disrupting the cell membranes. Furthermore, 1,4-dioxane caused biotoxicity to the intracellular activities of denitrifiers via disturbing carbon source utilization and interfering the key enzymes responsible for glycolysis. The decrease of microbial viability and activity inevitably resulted in the decline of key enzymes (NAR, NIR, NOR, and N 2 OR) closely related with denitrification process, which could be the direct reason for the decrease of denitrification performance.
研究领域:
环境生物学
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微生物学
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2025
·
IF 11.3
Man Xu,Xue Luo,Xin-Li Yan,Xiao-Yu Cai,Lin-Lin Wang,Feng Ge,Hong-Wei Wang
Etoxazole is a widely used insecticide that poses a serious threat to both ecosystems and human health. In present study, a novel strain Paracoccus versutus Y4 was isolated and identified. More than 98 % of the etoxazole (10 mg/L) was degraded as the sole carbon source within 8 d by strain Y4 in liquid culture. HPLC MS/MS analysis revealed three possible intermediates, and a novel metabolic pathway of etoxazole including oxidation, dehydrogenation, and hydrolysis reactions was proposed. The Toxicity Estimation Software Tool suggests that the biodegradation intermediates were less harmful than etoxazole. Whole-genome sequencing revealed that the genome size of P. versutus Y4 was 5320,902 bp containing 5187 coding sequences. Among them, the gene coding monooxygenase, dehydrogenase and hydrolase may be responsible for etoxazole biodegradation. The results of molecular docking analysis suggested that the monooxygenase, dehydrogenase, and hydrolase from strain Y4 may facilitate catalytic degradation through efficient substrate binding. Compared with diatomite carrier, fungal mycelium carrier can promote the growth of strain Y4. In the soil degradation experiments, the fungal mycelium carrier promoted etoxazole degradation by strain Y4 in both fresh and sterilized soil. Treatment with Y4 +fungal mycelium significantly reduced the half-life of etoxazole in fresh soil from 24.2 to 6.3 d. Our study is the first to isolate etoxazole-degrading bacteria and provides a new strategy for the bioremediation of pesticide pollution by combining degrading microbes and fungal mycelium carriers.
研究领域:
环境科学
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微生物学
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基因组学
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DOI
PubMed
高影响因子
Molecular Catalysis
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2021
·
IF 5.062
Wei Luo,Jiagui Hu,Jiapeng Lu,Huili Zhang,Xiaoping Wang,Yuantao Liu,Liqing Dong,Xiaobin Yu
ω-transaminase can mediate the asymmetric synthesis of chiral amines from aldehydes and ketones , which has important value in the synthesis of pharmaceutical intermediates. A novel ω-transaminase derived from Paracoccus pantotrophus ( Pp TA) was obtained and cloned in E. coli BL21(DE3) for expression. The enzyme has high activity for 2-ketobutyric acid and benzylamine , as well as for aromatic compounds with side chains longer than ethyl aliphatic hydrocarbons . Molecular simulation showed that the S-pocket in the active center is larger than those of other ω-transaminases. Thereafter, a whole-cell catalytic system was designed to prepare l -2-aminobutyric acid by cascading Pp TA and other enzymes. By using several strategies (regulation of RBS intensity, by-product decomposition and cofactor self-sufficiency), whole-cell cascade biocatalysis showed a high ee value (> 99%) and high yield (71%) in one pot reaction . This study therefore proposes an efficient biocatalyst for the synthesis of unnatural amino acids with the participation of ω-transaminase.
研究领域:
生物催化
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酶工程
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药物化学
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分子生物学
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DOI
高影响因子
CHEMOSPHERE
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2022
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IF 8.943
Bohan Yuan,Jiachao Yao,Zeyu Wang,Luyao Dai,Min Zhao,Dzmitry Hrynsphan,Savitskaya Tatsiana,Jun Chen
In this work, Rhodococcus ruber HJM-8 and Paracoccus communis YBH-X were isolated and used to enhance N , N -dimethylacetamide (DMAC) degradation and mineralization efficiencies. The monoculture and co-culture of the two strains for DMAC degradation were compared; results indicated that, a degradation efficiency of 97.62% was obtained in co-culture, which was much higher than that of monocultures of HJM-8 (57.34%) and YBH-X (34.02%). The degradation mechanism showed that co-culture could efficiently improve extracellular polymeric substances production, electron transfer , and microbial activity . Meanwhile, the mineralization mechanism suggested that acetate was the dominant intermediate which had an inhibitory effect on HJM-8, and co-culture was conducive to mineralization due to the high performance of acetate conversion and Na + K + -ATPase vitality. Besides, a pathway of DMAC biodegradation was proposed for co-culture: DMAC was degraded into acetate by HJM-8, then the accumulated acetate was mineralized by YBH-X. Additionally, the co-culture system was further optimized by Box-Behnken design.
研究领域:
环境微生物学
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生物修复
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化学工程
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PubMed
高影响因子
CHEMOSPHERE
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2020
·
IF 5.778
Jiexu Ye,Ni An,Han Chen,Zanyun Ying,Shihan Zhang,Jingkai Zhao
CO 2 is regarded as a major contributor to the global warming. CO 2 utilization is promising to reduce the CO 2 emissions. Currently, the biofixation of CO 2 using chemoautotrophs has markedly gain interest in CO 2 utilization. In this study, a newly isolated chemoautotroph, Paracoccus denitrificans PJ-1, was used for the biofixation of CO 2 under anaerobic condition . Experimental results revealed that Paracoccus denitrificans PJ-1 achieved a high carbon fixation rate (13.25 mg·L −1 ·h −1 ) which was ∼10 times faster than the previous reported chemotrophic bacteria using thiosulfate as electron donor. The best CO 2 fixation activity of Paracoccus denitrificans PJ-1 was achieved at the pH value of 9.0 and CO 2 concentration of 20 vol%. Meanwhile, a high CO 2 fixation yield of 106.03 mg·L −1 was reached. The presence of oxygen was adverse to the biofixation, indicating that strain PJ-1 was more suitable for CO 2 fixation in anaerobic environments. Carbon mass balance analysis revealed that the carbon from CO 2 was mainly fixed into the extracellular organic carbon rather than the biomass. GC-MS analysis and cbbL gene test revealed that Paracoccus denitrificans PJ-1 fixed CO 2 through the Calvin-Benson-Bassham cycle and mainly converted CO 2 to oxalic acid and succinic acid. Overall, the excellent CO 2 fixation capacity of Paracoccus denitrificans PJ-1 suggests that it had potential for CO 2 utilization.
研究领域:
环境科学
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微生物学
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生物技术
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气候变化
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DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
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2020
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IF 7.539
Junzhang Li,Zhaozhou Peng,Ruiyang Hu,Kaiyuan Gao,Chen Shen,Shouxin Liu,Runjing Liu
Accelerated denitrification is an essential problem in the biological treatment of nitrogenous wastewater. In this study, we report that denitrification is accelerated by micro-graphite particles (MGPs). The denitrification rate was increased by 83.4% or 11.1% in synthetic (with 0.16 g/L MGPs) or industrial nitrogenous wastewater (with 0.12 g/L MGP), respectively. The mechanism was revealed via a quantitative polymerase chain reaction (q-PCR), high-throughput sequencing, and scanning electron microscopy (SEM). The abundance of denitrifying bacteria Paracoccus in the sludge was increased by micro-graphite particles. The number of denitrifying bacteria with the nirS gene was increased significantly (75.6%). To the best of our knowledge, this is the first report that MGP could enhance denitrification via the sludge. MGP can denitrify in industrial applications.
研究领域:
环境生物学
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微生物学
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DOI
PubMed
高影响因子
ISME Journal
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2023
·Vol. 17
·期 12
·2169-2181
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IF 11
Wang Xia,Teng Ying,Wang Xiaomi,Xu Yongfeng,Li Ran,Sun Yi,Dai Shixiang,Hu Wenbo,Wang Hongzhe,Li Yanning,Fang Yan,Luo Yongming
Nitrogen is a limiting nutrient for degraders function in hydrocarbon-contaminated environments. Biological nitrogen fixation by diazotrophs is a natural solution for supplying bioavailable nitrogen. Here, we determined whether the diazotroph Azotobacter chroococcum HN can provide nitrogen to the polycyclic aromatic hydrocarbon-degrading bacterium Paracoccus aminovorans HPD-2 and further explored the synergistic interactions that facilitate pyrene degradation in nitrogen-deprived environments. We found that A. chroococcum HN and P. aminovorans HPD-2 grew and degraded pyrene more quickly in co-culture than in monoculture. Surface-enhanced Raman spectroscopy combined with 15 N stable isotope probing (SERS − 15 N SIP) demonstrated that A. chroococcum HN provided nitrogen to P. aminovorans HPD-2. Metabolite analysis and feeding experiments confirmed that cross-feeding occurred between A. chroococcum HN and P. aminovorans HPD-2 during pyrene degradation. Transcriptomic and metabolomic analyses further revealed that co-culture significantly upregulated key pathways such as nitrogen fixation, aromatic compound degradation, protein export, and the TCA cycle in A. chroococcum HN and quorum sensing, aromatic compound degradation and ABC transporters in P. aminovorans HPD-2. Phenotypic and fluorescence in situ hybridization (FISH) assays demonstrated that A. chroococcum HN produced large amounts of biofilm and was located at the bottom of the biofilm in co-culture, whereas P. aminovorans HPD-2 attached to the surface layer and formed a bridge-like structure with A. chroococcum HN. This study demonstrates that distinct syntrophic interactions occur between A. chroococcum HN and P. aminovorans HPD-2 and provides support for their combined use in organic pollutant degradation in nitrogen-deprived environments.
研究领域:
环境微生物学
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生物修复
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微生物生态学
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2025
·
IF 11.3
Min Li,Hongmei Wang,Xuan Qiu,Weiqi Wang,Xinyue Zhang,Deng Liu,Liyuan Ma,Xiaolu Lu
Microorganisms play a crucial role in the migration and transformation of antimony in mining areas, particularly under aerobic condition. However, whether and how microbes enhance the dissolution and oxidation of stibnite under anaerobic conditions remain poorly understood. This study used the facultative anaerobic antimony-oxidizing bacterium Paracoccus versutus XT0.6 to explore this under anaerobic conditions. XT0.6 couples the anaerobic oxidation of dissolved Sb(III) with denitrification, as indicated by shifts of antimony and nitrogen species. Interactions between XT0.6 and stibnite were conducted in closed systems with varying initial levels of oxygen (0%, 6%, 12%, 18%) and aerobic condition (21%). Results showed that XT0.6 inhibited the dissolution of stibnite and the release of Sb(III) within closed systems, regardless of the initial oxygen levels. This contrasts with aerobic conditions, where XT0.6 promoted stibnite dissolution and Sb release. In anaerobic abiotic closed system, total Sb concentration (TSb) was 41.7 mg/L with 16.8 mg/L as Sb(III). The presence of XT0.6 in the anaerobic closed system decreased TSb to 13.9 mg/L after day 3, with no Sb(III) detected. Similar patterns were observed in other closed systems with varying initial oxygen levels. Under aerobic condition, XT0.6 fully oxidized the released Sb(III) to Sb(V), resulting in a final concentration of 83.8 mg/L, while the abiotic control had a TSb of 69.8 mg/L with 36.3 mg/L as Sb(III). Light exposure enhanced chemical dissolution of stibnite (TSb 114.1 mg/L) and Sb(III) oxidation anaerobically but had no noticeable impact on microbial interaction with stibnite. As a semiconductor mineral, stibnite can generate reactive oxygen species upon light exposure, explaining the enhanced dissolution. The microbial inhibition of stibnite dissolution may be attributed to a passivation layer containing S-O bonds formed on the mineral surface by XT0.6 as demonstrated by XPS and SEM-EDS results. This study offers novel insights into the role of facultative anaerobic bacteria in antimony cycling, highlighting the importance of microbial-mineral interactions under anaerobic conditions.
研究领域:
环境微生物学
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生物地球化学
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地质微生物学
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锑元素循环
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矿物风化
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
·
IF 11.4
Liying Zhang,Xiaodan Ma,Qian Li,Hanlin Cui,Ke Shi,Hao Wang,Yanqing Zhang,Shuhong Gao,Zhiling Li,Ai-Jie Wang,Bin Liang
Sustainable nitrogen cycle is an essential biogeochemical process that ensures ecosystem safety and byproduct greenhouse gas nitrous oxide reduction. Antimicrobials are always co-occurring with anthropogenic reactive nitrogen sources. However, their impacts on the ecological safety of microbial nitrogen cycle remain poorly understood. Here, a denitrifying bacterial strain Paracoccus denitrificans PD1222 was exposed to a widespread broad-spectrum antimicrobial triclocarban (TCC) at environmental concentrations. The denitrification was hindered by TCC at 25 μg L–1 and was completely inhibited once the TCC concentration exceeded 50 μg L–1. Importantly, the accumulation of N2O at 25 μg L–1 of TCC was 813 times as much as the control group without TCC, which attributed to the significantly downregulated expression of nitrous oxide reductase and the genes related to electron transfer, iron, and sulfur metabolism under TCC stress. Interestingly, combining TCC-degrading denitrifying Ochrobactrum sp. TCC-2 with strain PD1222 promoted the denitrification process and mitigated N2O emission by 2 orders of magnitude. We further consolidated the importance of complementary detoxification by introducing a TCC-hydrolyzing amidase gene tccA from strain TCC-2 into strain PD1222, which successfully protected strain PD1222 against the TCC stress. This study highlights an important link between TCC detoxification and sustainable denitrification and suggests a necessity to assess the ecological risks of antimicrobials in the context of climate change and ecosystem safety.
研究领域:
环境科学
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微生物学
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气候变化
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生态系统安全
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产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2019
·
IF 7.913
Meng Jiang,Xiong Zheng,Yinguang Chen
Bio-denitrification (i.e., microbial reduction of nitrate to gaseous nitrogen) is usually reported to be affected by operating and environmental parameters, such as carbon source type, pH value, and temperature. In this paper, the enhancement of denitrification performance with the elimination of nitrite accumulation and nitrous oxide emission by Shewanella oneidensis MR-1 were investigated and the mechanisms were explored. It was found that S. oneidensis MR-1 itself had marginal nitrate removal capacity, but its presence in the denitrification system of a well-studied denitrifier (Paracoccus denitrificans ) obviously enhanced nitrate removal efficiency (from 65.3% to 97.8%) and reduced nitrite accumulation (0.67 against none-detectable) and N 2 O generation (from 8.87 μm/mM-TN to none-detectable). The mechanism study showed that S. oneidensis MR-1 promoted electrons transfer activity via the formation of nanotube between cells, which resulted in the increase of denitrification enzymes activity , carbon source metabolism, ATP level and cell viability. As the generation, transfer and consumption of electrons were enhanced by S. oneidensis MR-1, the improvement of denitrification performance with reduction of nitrite accumulation and N 2 O emission was therefore achieved. Finally, the performance of denitrification enhanced by S. oneidensis MR-1 was testified by laboratory groundwater treatment experiment. This study suggested the potential role of S. oneidensis MR-1 in accelerating nitrate bio-transformation in nitrogen geochemical cycle and increasing bio-treatment of nitrate contamination with negligible harmful intermediates (nitrite and N 2 O) accumulation.
研究领域:
环境微生物学
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生物技术
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水处理
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DOI
PubMed
高影响因子
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