海洋细菌THN1发酵产右旋糖酐酶的条件优化及酶学性质研究

Study on Optimization of Fermentation Conditions and Enzymatic Properties of Dextranase Produced by Marine Bacteria THN1

为提高海洋细菌THN1产右旋糖酐酶的能力,本研究利用单因素试验和响应面试验对菌株THN1的发酵条件进行优化,并探究菌株THN1右旋糖酐酶的酶学性质。优化结果表明,菌株THN1的最佳产酶条件为麸皮5 g/L、胰蛋白胨20 g/L、NaCl 10 g/L、右旋糖酐T20 5 g/L,陈海水配置,pH值为8.2,30℃培养24 h。在此条件下,菌株THN1的发酵液酶活力达到3.71 U/mL,是优化前(初始酶活力为0.12 U/mL)的31倍。酶学性质分析表明,右旋糖酐酶的最适反应温度为40℃,在30℃条件下放置5 h酶活力基本保持稳定;最适反应pH值为7.5,在pH值为5.0-9.0的条件下相对酶活力能保持50%以上。本研究成果可为缩短右旋糖酐酶生产周期和降低成本提供数据支撑,并认为菌株THN1右旋糖酐酶在口腔护理方面具有良好的应用潜力。

In order to increase the dextranase production ability of a marine bacterium THN1,the fermentation conditions of strain THN1 were optimized by single factor test and response surface test, and the enzymatic properties of strain THN1 dextranase were explored in this study.The optimization results showed that the optimal dextranase production conditions of strain THN1 were as follows: wheat bran 5 g/L,tryptone 20 g/L,NaCl 10 g/L,dextran T20 5 g/L,aged seawater configuration, pH 8.2,and incubation at 30℃ for 24 h.Under these conditions, the enzyme activity in the fermentation broth of strain THN1 reached 3.71 U/mL,it was 31 times that before optimization(the initial enzyme activity was 0.12 U/mL).Enzymatic properties analysis showed that the optimum reaction temperature of the dextranase was 40℃,and it was basically stable at 30℃ for 5 h.The optimum reaction pH was 7.5,and the relative enzyme activity can maintain more than 50% under the condition of pH 5.0-9.0.The results of this research can provide data support for shortening the production cycle of dextranase and reducing costs.It is believed that strain THN1 dextranase has good application potential in oral care.