BIORESOURCE TECHNOLOGY
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2017
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IF 5.651
Zisheng Zhao,Yang Li,Qilin Yu,Yaobin Zhang
ZVI was reported to enrich H 2 -utilizing methanogens that enhanced interspecies H 2 transfer, while Fe(III) oxide served as a conductive material to promote direct interspecies electron transfer (DIET). However, the interaction of these two modes in anaerobic digestion has not been clarified yet. In this study, when adding Fe 3 O 4 and ZVI simultaneously into an anaerobic digester, the abundance of hydrogenotrophic methanogens decreased drastically compared to ZVI-added digester and Fe-free digester. However, the methane production of ZVI + Fe 3 O 4 added digester were 68.9% higher than Fe-free digester and 20.0% higher than ZVI-added digester, respectively. Sludge reduction rate of these three digesters also showed similar results. These indicated that hydrogenotrophic methanogenesis was not the main reason for methanogenesis in Fe 3 O 4 -added digester. Instead, Syntrophomonas and Methanosaeta were specially enriched in Fe 3 O 4 -added digesters, which implied that the potential DIET between Syntrophomonas and Methanosaeta was likely a crucial reason for accelerating anaerobic digestion of waste sludge.
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DOI
高影响因子
Frontiers in Bioengineering and Biotechnology
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2022
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IF 6.064
Xinming Feng,Yujin Cao,Wei Liu,Mo Xian
Fluoride plays an important role in the fields of materials and medicine. Compared with chemical synthesis, fluorinases are natural catalysts with more application potential, which provide a green and effective way to obtain organofluorine. However, the application of fluorinases is limited by certain factors, such as the limited number of enzymes and their low activity. In this work, two new fluorinases from Amycolatopsis sp. CA-128772 and Methanosaeta sp. PtaU1.Bin055 were identified by gene mining and named Fam and Fme, respectively. The activities of these two enzymes were reported for the first time, and Fme showed good thermal stability, which was different from the reported fluorinases. In addition, the activity toward natural substrate of Fam was improved by site-directed mutagenesis, the catalytic efficiency ( k cat /K m ) of the best mutant containing two amino acid substitutions (T72A and S164G) toward the substrate S-adenosyl-L-methionine was improved by 2.2-fold compared to the wild-type. Structural modeling analysis revealed that the main reason for the increased enzyme activity might be the formation of a new substrate channel. Experimental evidence suggests that the substrate channel may indeed play a key role in regulating the function of the fluorinases.
研究领域:
生物化学
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酶学
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生物催化
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合成生物学
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DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
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2022
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IF 11.889
Xia He,Weijia Xu,Jian Lu,Jun Wu,Zhenyu Guo,Xuerui Wei,Chun Wang
To investigate the combination of carbon-based conductive materials and exogenous hydrogen (EH 2 ) on methane recovery from fat, oil, and grease (FOG), granular activated carbon (GAC) and carbon cloth (CC) were chosen to collaborate with EH 2 , resulting in increased methane production by 59 % and 84 %, respectively. Further digestion of long chain fatty acids (LCFAs) confirms that enhanced direct interspecies electron transfer (DIET) was achieved in the reactors with GAC/CC + EH 2 than those with GAC/CC only. Other evidences (such as increased microbial population and rapid degradation of volatile fatty acids) were found to support the role of GAC/CC + EH 2 in promotion of DIET. Significant change of microbial community was observed using GAC/CC + EH 2 , which was mainly attributed to the enrichment of electrogenic species (such as Spirochaetaceae , Syntrophomonas palmitatica , and Methanosaeta ), leading to some changes in metabolic pathways during acidogenesis and methanogenesis. Together, enhanced DIET was achieved by GAC/CC + EH 2 , thus improving the methane recovery from FOG.
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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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
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2024
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IF 7.7
Sheng-Jie Sun,Fei Wang,Zhang-Wei He,Cong-Cong Tang,Ai-Juan Zhou,Yong-Xiang Ren,Zhihua Li,Wenzong Liu
To recover methane from waste activated sludge through anaerobic digestion (AD) is one promising alternative to achieve carbon neutrality for wastewater treatment plants. However, humic acids (HAs) are one of the major compositions in waste activated sludge, and their accumulation performs inhibition effects on AD. This study investigated the potentials of biochar (BC) in alleviating inhibition effects of HAs on AD. Results showed that although the accumulated HAs reduced methane yield by 9.37% compared to control, the highest methane yield, 132.6 mL CH 4 /g VSS, was obtained after adding BC, which was 45.9% higher than that in HA group. Mechanism analysis showed that BC promoted the activities of hydrolase such as protease and α-glucosidase, which were 69.7% and 29.7% higher than those in HA group, respectively. The conversion of short-chain fatty acids was accelerated. In addition, the evolutions of electroactive microorganisms like Clostridium_sensu_stricto_13 and Methanosaeta were consistent with the activitiies of electron transfer and the contents of cytochrome c . Furthermore, parts of HAs rather than all of them were adsorbed by BC, and the remaining free HAs and BC formed synergistic effects on methanogenesis, then both CO 2 reduction and acetoclastic methanogenesis pathways were improved. The findings may provide some solutions to alleviate inhibition effects of HAs on AD.
研究领域:
环境科学
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废水处理
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生物气体生产
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微生物生态学
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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）