JOURNAL OF APPLIED MICROBIOLOGY
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2023
·Vol. 134
·期 4
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IF 4
Xiang Yang,Xiong Jia-Xi,Xie Ze-Feng,Huang Duo,Song Qi,Wu Jing,Yan Dazhong,Chao Hong-Jun
AimsPandoraea pnomenusa MCB032 completely degrades chlorobenzene, whose metabolic pathway is encoded by cbs and clc gene clusters. The putative regulatory factors ClcR and CbsR are predicted to regulate the cbs and clc gene clusters. This research aims to understand the function of ClcR and CbsR.Methods and resultsRT-PCR analyses demonstrated that the cbsFAaAbAcAdB operon that encodes catabolic pathways for the degradation of chlorobenzene to chlorocatechol is located on an operon. Moreover, the clcABCDE operon is involved in the 3-chlorocatechol pathway. Gene knockout and transcriptional analysis showed that the transcription of the cbsFAaAbAcAdB operon is positively regulated by CbsR, whereas the clcABCDE operon is activated by ClcR. Primer extension analysis was used to locate the transcription start sites of the cbsFAaAbAcAdB and cbsR operons. Electrophoretic mobility shift assay analyses showed that CbsR is bound to the sites in the promoter regions of cbsFAaAbAcAdB and cbsR operons.ConclusionThe XylR/NtrC-type regulator CbsR positively regulates the transcription of the cbsFAaAbAcAdB operon encoding the upstream pathway of chlorobenzene catabolism, while the LysR-type regulator ClcR activates the clcABCDE operon encoding the downstream pathway.
研究领域:
微生物学
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环境科学
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分子生物学
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL MICROBIOLOGY
·
2024
·
IF 2.3
Pan Lixu,Yuan Bo,Li Qingqing,Ouyang Ji,Yang Jie,Zhou Yan,Cui Changzheng
Chlorobenzene (CB), extensively used in industrial processes, has emerged as a significant contaminant in soil and groundwater. The eco-friendly and cost-effective microbial remediation has been increasingly favored to address this environmental challenge. In this study, a degrading bacterium was isolated from CB-contaminated soil at a pesticide plant, identified as Pandoraea sp. XJJ-1 (CCTCC M 2021057). This strain completely degraded 100 mg·L −1 CB and showed extensive degradability across a range of pH (5.0–9.0), temperature (10–37 °C), and CB concentrations (100–600 mg·L −1 ). Notably, the degradation efficiency was 85.2% at 15 °C, and the strain could also degrade six other aromatic hydrocarbons, including benzene, toluene, ethylbenzene, and xylene ( o- , m- , p- ). The metabolic pathway of CB was inferred using ultraperformance liquid chromatography, gas chromatography-mass spectrometry, and genomic analysis. In strain XJJ-1, CB was metabolized to o -chlorophenol and 3-chloroxychol by CB monooxygenase, followed by ortho- cleavage by the action of 3-chlorocatechol 1,2-dioxygenase. Moreover, the presence of the chlorobenzene monooxygenation pathway metabolism in strain XJJ-1 is reported for the first time in Pandoraea . As a bacterium with low-temperature resistance and composite pollutant degradation capacity, strain XJJ-1 has the potential application prospects in the in-situ bioremediation of CB-contaminated sites.
研究领域:
环境科学
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微生物学
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生物修复
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Huili Zeng,Jingyi Huang,Minghuo Wu,Minjie Hu,Xiaojing Yang,Hao Zhou,Jingjing Zhan,Xuwang Zhang
As a representative polycyclic aromatic hydrocarbon (PAH), pyrene poses a significant threat to the environment and public health due to its persistence and potential toxicity. Extensive research has been conducted on biodegradation of pyrene, highlighting the crucial need to unravel its degradation mechanisms. Coastal and marine sediments are promising sources for discovering microbial candidates capable of degrading pyrene. In this study, three bacterial consortia, designated as BS, YS, and SS, were enriched from sediments collected from the Bohai Sea, Yellow Sea, and Liao River estuarine wetland, respectively. The bacterial consortia BS, YS, and SS demonstrated high pyrene degradation efficiencies, achieving 86.61 %, 80.39 %, and 75.70 % degradation at the concentration of 50 mg/L within 8 days, respectively. High-throughput sequencing of 16S rRNA gene amplicons revealed Pandoraea , Delftia , and Pseudomonas as the dominant populations in bacterial consortia BS, YS, and SS, respectively, with some species potentially being novel pyrene degraders. Further analysis included identifying pyrene degradation metabolites by LC-Q-TOF-MS (high-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry) and predicting functional genes through PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved Stats). Based on these results, the metabolic pathways for pyrene degradation by the bacterial consortia were proposed, which predominantly involved the dioxygenation pathway. Overall, these findings should offer valuable bacterial resources for facilitating the bioremediation of PAH-contaminated environments.
研究领域:
环境微生物学
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生物修复
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海洋生态学
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分子生物学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）