• 동아시아식생활학회지
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• 제26권2호
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• pp.192-199
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• 2016

The antioxidative activity and antimutagenic activity of the ethanol extracts from pericarp and seeds of wild grape (Vitis coignetiea) were analyzed in this study. The antioxidative activity of the extracts from wild grape was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. The antimutagenic activity of the extracts was evaluated on Salmonella typhimurium TA98 and TA100 by Ames test using 4-nitroquinoline 1-oxide (4-NQO) and sodium azide as mutagens. In the antioxidative activity determination, $IC_{50}$ values of the DPPH radical scavenging activity of the extracts from pericarp and seeds were 27.16 ppm and 7.61 ppm, respectively. Additionally, ABTS radical scavenging activities of pericarp and seed extract were 99.75% and 98.87% at 200 ppm, respectively. In the antimutagenic activity determination, pericarp extract at 5 mg/plate inhibited 72.6% and 74.3% of mutagenicity of S. typhimurium TA98 induced by 4-NQO and sodium azaid, respectively. Also, the mutagenicity inhibition rates of seed extract at 5 mg/plate were 77.8% and 74.5% in S. typhimurium TA100 induced by 4-NQO and sodium azaid, respectively. These results demonstrate that the ethanol extract from wild grape has remarkable antioxidant activity and antimutagenicity.

• Journal of Microbiology and Biotechnology
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• 제34권4호
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• pp.930-939
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• 2024

Mushroom laccases play a crucial role in lignin depolymerization, one of the most critical challenges in lignin utilization. Importantly, laccases can utilize a wide range of substrates, such as toxicants and antibiotics. This study isolated a novel laccase, named HeLac4c, from endophytic white-rot fungi Hericium erinaceus mushrooms. The cDNAs for this enzyme were 1569 bp in length and encoded a protein of 523 amino acids, including a 20 amino-acid signal peptide. Active extracellular production of glycosylated laccases from Saccharomyces cerevisiae was successfully achieved by selecting an optimal translational fusion partner. We observed that 5 and 10 mM Ca²⁺, Zn²⁺, and K⁺ increased laccase activity, whereas 5 mM Fe²⁺ and Al³⁺ inhibited laccase activity. The laccase activity was inhibited by the addition of low concentrations of sodium azide and ⳑ-cysteine. The optimal pH for the 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt was 4.4. Guaiacylglycerol-β-guaiacyl ether, a lignin model compound, was polymerized by the HeLac4c enzyme. These results indicated that HeLac4c is a novel oxidase biocatalyst for the bioconversion of lignin into value-added products for environmental biotechnological applications.