Environmental Science and Ecotechnology
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2024
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IF 14
Bingjie Xue,Li Tian,Yaqi Liu,Lingxiu Peng,Waheed Iqbal,Liangzhong Li,Yanping Mao
Addressing nitrate contamination in water bodies is a critical environmental challenge, and Intimately Coupling Photocatalysis and Biodegradation (ICPB) presents a promising solution. However, there is still debate about the effectiveness of ICPB in reducing nitrate under hypotrophic conditions. Further research is needed to understand its microbial metabolic mechanism and the functional changes in bacterial structure. Here we explored microbial metabolic mechanisms and changes in bacterial structure in ICPB reactors integrating a meticulously screened TiO 2 /g-C 3 N 4 photocatalyst with biofilm. We achieved a 26.3% increase in nitrate reduction using 12.2% less organic carbon compared to traditional biodegradation methods. Metagenomic analysis of the microbial communities in ICPB reactors revealed evolving metabolic pathways conducive to nitrate reduction. This research not only elucidates the photocatalytic mechanism behind nitrate reduction in hypotrophic conditions but also provides genomic insights that pave the way for alternative approaches in water remediation technologies.
研究领域:
环境科学
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水处理
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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
ISME Journal
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2021
·Vol. 15
·期 6
·1844-1857
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IF 10.302
Liu Qing,Li Wei,Liu Di,Li Lingyan,Li Jie,Lv Na,Liu Fei,Zhu Baoli,Zhou Yuguang,Xin Yuhua,Dong Xiuzhu
Bacteria that inhabit glaciers usually produce carotenoids. Here, we report that a group of zeaxanthin-producing glacial Flavobacterium exhibited light-promoted growth. Of the tested 47 strains, 45 showed increased growths but two died under illumination at 50 μmol photon m −2 s −1 . Light stimulation occurred mainly in either anoxic or nutrient-poor cultures, while the same levels of light promotion were found for that grown at 14 and 7 °C. Pigment assays identified overrepresentative zeaxanthin but trace retinal in the light promoted 45 strains, while flexirubin was exclusively in the light-lethal two. Genomic analysis revealed the gene cluster for zeaxanthin synthesis in the 45 strains, in which 37 strains also harbored the proteorhodopsin gene prd . Transcriptomic analysis found that light-induced expressions of both the zeaxanthin synthesis and proteorhodopsin genes. Whereas, deletion of the prd gene in one strain did not diminish light promotion, inhibition of zeaxanthin synthesis did. In comparison, no light promotion was determined in a glacier Cryobacterium luteum that produced a non-zeaxanthin-type carotenoid. Therefore, light stimulation on the glacial Flavobacterium is mostly likely related to zeaxanthin, which could provide better photoprotection and sustain membrane integrity for the organisms living in cold environments.
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
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2025
·
IF 11.3
Sitong Liu,Kun Feng,Dawei Zhang,Yang Liu,Jing Wang,Baiyun Lu,Defeng Xing
Understanding the stability and assemblage of biofilm microbiomes under oligotrophic conditions is critical for improving groundwater bioremediation. In this study, a novel microbial electrochemical filter (MEF) was developed to explore the impact of weak electrical stimulation on functional adaptability of biofilms under oligotrophic and 1,4-dioxane exposure conditions. Under 20 mg/L 1,4-dioxane stress, the MEF achieved 94.72 % manganese removal and 27.27 % ammonia nitrogen removal, while the conventional biofilter exhibited 88.76 % manganese removal with negligible ammonia nitrogen removal. Metagenomics analyses revealed that dominant populations in the MEF included Nitrospira , Bradyrhizobium , and Nitrosomonas , with relative abundance of 6.23 −10.78 %, 5.81 −6.15 %, and 1.62 −5.58 %, respectively. Weak electrical stimulation enriched the manganese oxidation-associated genes cotA , mnxG , and mcoA , whose total relative abundances being 6.3 times that of the conventional biofilter before dioxane exposure and 2.0 times after exposure. Genes encoding ammonia monooxygenase ( amoABC ), hydroxylamine dehydrogenase ( hao ) increased by 2.4- and 1.9-fold, respectively, compared to the conventional biofilter. Additionally, genes involved in the reductive tricarboxylic acid cycle and nitrogen fixation were twice as abundant in the MEF than in the conventional biofilter, suggesting enhanced nutrients availability for heterotrophic bacteria during start-up. These findings demonstrated that weak electrical stimulation effectively regulated biofilm microbiomes and enhance pollutant removal in MEF under oligotrophic conditions.
研究领域:
环境生物技术
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微生物生态学
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水处理技术
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宏基因组学
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电化学
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产品关联
DOI
PubMed
高影响因子
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