Royal Society Open Science
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2020
·Vol. 7
·期 8
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IF 2.646
Ming Gao,Shuang Zhang,Xinxin Ma,Weijie Guan,Na Song,Qunhui Wang,Chuanfu Wu
Food waste contains numerous easily degradable components, and anaerobic digestion is prone to acidification and instability. This work aimed to investigate the effect of adding yeast on biogas production performance, when substrate is added after biogas production is reduced. The results showed that the daily biogas production increased 520 and 550 ml by adding 2.0% (volatile solids; VS) of activated yeast on the 12th and 37th day of anaerobic digestion, respectively, and the gas production was relatively stable. In the control group without yeast, the increase of gas production was significantly reduced. After the second addition of substrate and yeast, biogas production only increased 60 ml compared with that before the addition. After fermentation, the biogas production of yeast group also increased by 33.2% compared with the control group. Results of the analysis of indicators, such as volatile organic acids, alkalinity and propionic acid, showed that the stability of the anaerobic digestion system of the yeast group was higher. Thus, the yeast group is highly likely to recover normal gas production when the biogas production is reduced, and substrate is added. The results provide a reference for experiments on the industrialization of continuous anaerobic digestion to take tolerable measures when the organic load of the feed fluctuates dramatically.
研究领域:
环境生物学
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微生物学
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可再生能源
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2021
·
IF 6.498
Shuting Zeng,Jing Sun,Ziwei Chen,Qiuxiang Xu,Wei Wei,Dongbo Wang,Bing-Jie Ni
Clarithromycin retained in waste activated sludge (WAS) inevitably enters the anaerobic digestion system. So far, the complex impacts and fate of clarithromycin in continuous operated WAS anaerobic digestion system are still unclear. In this study, two semi-continuous long-term reactors were set up to investigate the effect of clarithromycin on biogas production and antibiotic resistance genes (ARGs) during WAS anaerobic digestion, and a batch test was carried out to explore the potential metabolic mechanism. Experimental results showed that clarithromycin at lower concentrations (i.e., 0.1 and 1.0 mg/L) did not affect biogas production, whereas the decrease in biogas production was observed when the concentration of clarithromycin was further increased to 10 mg/L. Correspondingly, the relative abundance of functional bacteria in WAS anaerobic digestion (i.e., Anaerolineaceae and Microtrichales ) was reduced with long-term clarithromycin exposure. The investigation of ARGs suggested that the effect of methylation belonging to the target site modification played a critical role for the anaerobic microorganisms in the expression of antibiotic resistance, and ermF , played dominated ARGs, presented the most remarkable proliferation. In comparison, the role of efflux pump was weakened with a significant decrease of two detected efflux genes. During WAS anaerobic digestion, clarithromycin could be partially degraded into metabolites with lower antimicrobial activity including oleandomycin and 5-O-desosaminyl-6-O-methylerythronolide and other metabolites without antimicrobial activity.
研究领域:
环境科学
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微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Energies
·
2021
·Vol. 14
·期 11
·2990
·
IF 3.004
Qing Zhang,Jing Zhang,Shuai Zhao,Peizhi Song,Yanli Chen,Pu Liu,Chunlan Mao,Xiangkai Li
Lignin-feeding insect gut is a natural ligninolytic microbial bank for the sustainable conversion of crop straw to biogas. However, limited studies have been done on highly efficient microbes. Here, an efficient ligninolytic strainEnterobacter hormaecheiKA3 was isolated from the gut microbiomes of lignin-feedingHypomeces squamosusFabricius, and its effects on lignin degradation and anaerobic digestion were investigated. No research has been reported. Results showed that strain KA3 had better lignin-degrading ability for corn straw with a higher lignin-degrading rate (32.05%) and lignin peroxidase activity (585.2 U/L). Furthermore, the highest cumulative biogas yield (59.19 L/kg-VS) and methane yield (14.76 L/kg-VS) were obtained for KA3 inoculation, which increased by 20% and 31%, respectively, compared to CK. Higher removal rates of COD, TS, and vs. of 41.6%, 43.11%, and 66.59% were also found. Moreover, microbial community diversity increased as digestion time prolonged in TG, and bacteria were more diverse than archaea. The dominant genus taxon, for methanogens, wasMethanosatein TG, while in CK wasMethanosarcina. For bacteria, dominant taxa were similar for all groups, which wereSolibacillusandClostridium. Therefore, strain KA3 improved the methane conversion of the substrate. This study could provide a new microbial resource and practical application base for lignin degradation.Keywords:microbial lignin degradation;gut microbiome;Enterobacter hormaecheiKA3;biogas production;microbial community
研究领域:
微生物学
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环境科学
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生物能源
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
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2019
·
IF 6.395
Minrui Liu,Hongyuhang Ni,Ling Yang,Gang Chen,Xiaojun Yan,Xiaoyun Leng,Pu Liu,Xiangkai Li
Biogas is one of the most popular renewable alternatives. Large quantities of antibiotics are used for rearing livestock resulting in the presence of high levels of antibiotics in manure, inhibiting biogas production during anaerobic digestion . In this study, a novel whole-cell biocatalyst that can accelerate degradation of antibiotics was developed by displaying β-lactamase on the cell surface of Escherichia coli . This biocatalyst showed high enzyme activity (4.93 ± 0.77 U/g dry weight of cells) in degrading β-lactam antibiotics and higher stability at room temperature than free β-lactamase. Penicillin, cefamezin, and amoxicillin were completely degraded in solution by the biocatalyst within 1 h. Pretreatment of swine manure containing 50 mg/kg and 100 mg/kg of penicillin, cefamezin, and amoxicillin with the new biocatalyst enhanced methane production by 37.1% and 93.2%, respectively during anaerobic digestion. The engineered biocatalyst protected the microbial community from antibiotic inhibition and hence is conducive for the growth of methanogens . This new strategy eliminates the inhibiting effects of antibiotics on manure, increasing the methane production and therefore achieving maximum utilization of renewable energy during anaerobic digestion. This pretreatment technology provides a new idea to treat manure containing antibiotics and improve energy efficiency.
研究领域:
环境科学
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生物技术
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2024
·
IF 8
Hamza Hassan Yusuf,Xiaofang Pan,Zhi-Long Ye,Guanjing Cai,Lise Appels,Jiasheng Cai,Zunjing Lv,Yanlin Li,Jing Ning
To achieve the UN Sustainable Development Goals (SDGs) and the China Toilet Revolution on a global scale, it is crucial to implement a decentralized sanitation management system in developing countries. Fecal slags (FS) generated from septic tanks of toilets pose a challenge for remote villages. This study sought to resourcefully utilize FS through co-digesting with food waste (FW) under high-solid anaerobic co-digestion (HSAD). Besides, two metallic nanomaterials , nano-zerovalent iron (nZVI) and magnetite (Fe 3 O 4 ), were employed to demonstrate the practical improvement of HSAD. The results showed that nZVI-dosed digesters produced the highest cumulative methane of 295.72 mL/gVS, 371.36 mL/gVS, 360.53 mL/gVS and 296.64 mL/gVS in 10%, 15%, 20% and 25% TS content, respectively, which was 1.15, 1.22, 1.16, 1.12 times higher than Fe 3 O 4 dosed digesters. This increment could be ascribed to the simultaneous production of H 2 from Fe 2+ release from nZVI and the enrichment of homoacetogen. Changes in carbon degradation and methanogenic pathways, which facilitated stability under high TS contents, were observed. At low solid digestion (10% TS), Syntrophomonas cooperated with Methanosarcina and Methanobacterium to metabolize butyrate and propionate. However, due to the buildup of total ammonia nitrogen and volatile fatty acids, acetoclastic methanogens were inhibited in the high-solid digesters (15%, 20% and 25% TS). Consequently, a more resilient and highly tolerant Syntrophaceticus , alongside hydrogenotrophic methanogens such as Methanoculleus and Methanobrevibacter , maintained stability in the harsh environment.
研究领域:
环境工程
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可持续发展
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废物管理
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纳米技术
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沼气生产
✓ 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）