JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2018
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IF 3.412
Jingjing Bao,Nian Liu,Liying Zhu,Qing Xu,He Huang,Ling Jiang
Chitin is used as an essential raw material for the production of glucosamine (GlcN). In this study, we adopted three key enzymes, isolated from Thermococcus kodakaraensis KOD1, that catalyze the sequential conversion of α-chitin into GlcN and developed a multienzyme-assembly-cascade (MAC) system immobilized in a bacterial biofilm, which enabled a multistep one-pot reaction. Specifically, the SpyTag–SpyCatcher and SnoopTag–SnoopCatcher pairs provided covalent and specific binding force to fix enzymes to the biofilm one by one and assemble close enzyme cascades. The MAC system showed great catalytic activity, converting 79.02 ± 3.61% of α-chitin into GlcN with little byproducts, which was 2.09 times that of GlcN catalyzed by a mixture of pure enzymes. The system also exhibited good temperature and pH stability. Notably, 90% of enzyme activity was retained after 6 rounds of reuse, and appreciable activity remained after 17 rounds.
研究领域:
生物化学
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生物技术
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酶学
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产品关联
DOI
PubMed
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
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2021
·
IF 3.978
Chi Wang,Pei-Xu Chen,Qiong Xiao,Jun Chen,Fu-Quan Chen,Qiu-Ming Yang,Hui-Fen Weng,Bai-Shan Fang,Yong-Hui Zhang,An-Feng Xiao
Naringinase is a kind of glycosidase that catalyzes the biotransformation of naringin into naringenin . It is a multi-compound enzyme that provides the activity of α- L -rhamnosidase and β-glucosidase. In this study, an artificial naringinase system was constructed by co-immobilizing α- L -rhamnosidase ( Aspergillus oryzae FJ0123, Ao-rha) and β-glucosidase ( Thermotoga maritima MSB8, Tm-glu) on magnetic silica-based chitosan microspheres (MSC). The molar ratio of enzymes and the preparation conditions were optimized for improving synergistic effect and immobilization efficiency. Under optimized conditions (the molar ratio of Ao-rha and Tm-glu, 3:1; temperature, 25 °C; glutaraldehyde concentration, 2.0%; pH, 3.0; time, 9 h), the immobilization yield and activity recovery were 61.4% and 37.3% for Ao-rha and 90.1% and 56.3% for Tm-glu, respectively. Biochemical characterization indicated that MSC-naringinase had better adaptability and stability than free enzymes. The activity of MSC-naringinase was maintained at 58.7% after 10 times of recycling. The catalytic conditions were also investigated. The cascade reactions of naringin to prunin and prunin to naringenin by using MSC-naringinase resulted in a yield of 0.62 mg/mL and a conversion rate of 96.9%, respectively, without prunin accumulation. These results indicated the great potential of MSC-naringinase as an efficient artificial naringinase system for cooperative enzymatic synthesis of naringenin.
研究领域:
生物化学
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酶学
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生物技术
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 49
·108162-108175
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IF 5.8
Lu Yuanyuan,Pang Lina,Chatzisymeon Efthalia,Liu Xuna,Xu Kailin,Yang Ping,Gou Min
The metagenomics-based behavior and risk of antibiotic resistance genes (ARGs) were investigated during cattle manure thermophilic anaerobic digestion with tetracycline and copper, namely, bulk-copper oxide, nano-copper oxide, and copper sulfate, which are common feed additives. Although bulk-copper oxide reduced ARGs’ diversity, it enriched high-risk ARGs the most than the other two copper species, while copper sulfate could strongly mitigate the ARG risk by decreasing their abundances. Compared to corresponding individual effects, copper and tetracycline combinations may decrease ARGs’ co-occurrence potential by 22.0%, and particularly, tetracycline combined separately with copper sulfate and nano-copper oxide reduces the ARGs’ risk in abundance (by 7.2%) and human health (by 4.0%). These were mainly driven by bioavailable copper, volatile fatty acids, and pH, as well as the main potential hosts in phyla Firmicutes, Coprothermobacterota, and Euryarchaeota. Notably, the twin risks of pathogenicity and ARGs should be emphasized due to the ARGs’ positive correlation with human pathogens of Clostridioides difficile and Arcobacter peruensis . These findings are important for understanding the potential ARGs’ risk in treatments of livestock wastes containing feed additives of different sizes and speciation.
研究领域:
环境科学
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微生物学
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宏基因组学
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生物技术
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动物废物管理
✓ 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）