一株琼胶酶菌株的筛选及产酶条件的优化

Isolation of an agarase-producing strain and optimization of its cultivation for high agarase activity

从大连周边海域采集的海藻中筛选得到一株可降解琼胶的菌株D3。对菌株D3进行发酵实验,通过响应面法对产琼胶酶条件进行优化,获得最佳培养条件为:100 mL发酵液中含有琼脂0.255 g,NaCl 2.268 g,蛋白胨0.448 g,葡萄糖0.3 g,pH6.5,30℃培养,转速150 r/min,接种量为1.5%(v/v)。优化后酶活达到274.32 U/mL,是优化前的2.71倍。

An agar-degrading bacterium D3 was isolated from the seaweeds in the sea area of Dalian. Fermentation by D3 was performed based on response surface methodology （RSM） to optimize its cultivation conditions for enhanced agarase activity. The optimized condition was as followed （100 mL）： agar 0.255 g, NaCI 2.268 g, peptone 0,448 g, glucose 0.3 g, pH 6.5, and the temperature maintained at 30 ℃ with a rotation rate of 150 r/rain and the inoculation at 1.5%（v/v）. The agarase activity reached 274.32 U/mL afterwards, which was 2.71 folds of that before optimization.