Doan Chien Thang, Tran Thi Ngoc, Wang San-Lang
Faculty of Natural Sciences and Technology, Tay Nguyen University, Buon Ma Thuot 630000, Vietnam.
Department of Chemistry, Tamkang University, New Taipei City 25137, Taiwan.
Polymers (Basel). 2021 Sep 9;13(18):3048. doi: 10.3390/polym13183048.
The bioprocessing of chitinous fishery wastes (CFWs) to chitinases through fermentation approaches has gained importance owing to its great benefits in reducing the enzyme production cost, and utilizing chitin waste. In this work, our study of the chitinase production of sp. TKU052 in the presence of different kinds of CFWs revealed a preference for demineralized crab shells powder (deCSP); furthermore, a 72 kDa chitinase was isolated from the 0.5% deCSP-containing medium. The sp. TKU052 chitinase displayed maximum activity at 70 °C and pH 4-5, while Zn, Fe, Triton X-100, Tween 40, and SDS exerted a negative effect on its activity, whereas Mn and 2-mercaptoethanol were found to potentially enhance the activity. Among various kinds of polysaccharide, sp. TKU052 chitinase exhibited the best catalytic activity on colloidal chitin (CC) with K = 9.75 mg/mL and V = 2.43 μmol/min. The assessment of the hydrolysis of CC and -acetyl chitooligosaccharides revealed that sp. TKU052 chitinase possesses multiple catalytic functions, including exochitinase, endochitinase, and -acetyl-β-D-glucosaminidase activities. Finally, the combination of sp. TKU052 chitinase and TKU048 -acetyl-β-D-glucosaminidase could efficiently convert CC to -acetyl-D-glucosamine (GlcNAc) with a production yield of 94.35-98.60% in 12-24 h.
通过发酵方法将含几丁质的渔业废弃物（CFW）生物加工成几丁质酶，因其在降低酶生产成本和利用几丁质废弃物方面的巨大益处而变得愈发重要。在这项工作中，我们对sp. TKU052在不同种类CFW存在下产几丁质酶的研究表明，它更偏好脱矿化蟹壳粉（deCSP）；此外，从含0.5% deCSP的培养基中分离出一种72 kDa的几丁质酶。sp. TKU052几丁质酶在70°C和pH 4 - 5时表现出最大活性，而锌、铁、吐温X - 100、吐温40和十二烷基硫酸钠对其活性有负面影响，而锰和2 - 巯基乙醇则可能增强其活性。在各种多糖中，sp. TKU052几丁质酶对胶体几丁质（CC）表现出最佳催化活性，K = 9.75 mg/mL，V = 2.43 μmol/min。对CC和N - 乙酰壳寡糖水解的评估表明，sp. TKU052几丁质酶具有多种催化功能，包括外切几丁质酶、内切几丁质酶和N - 乙酰 - β - D - 氨基葡萄糖苷酶活性。最后，sp. TKU052几丁质酶和TKU048 N - 乙酰 - β - D - 氨基葡萄糖苷酶的组合能够在12 - 24小时内将CC高效转化为N - 乙酰 - D - 葡萄糖胺（GlcNAc），产率为94.35 - 98.60%。
