产木聚糖酶海洋微生物的筛选与诱变育种
Screening and breeding by induced mutation of xylanase-producing marine microorganism

以自制木聚糖为初筛培养基的唯一碳源，从多个海洋来源样品中一共筛到60株有透明圈且形态各异的菌株，摇瓶发酵结果显示，38株具有产木聚糖酶能力，其中B659菌株产酶能力最高，酶活力为525.3 U·mL-1. 结合B659菌株的形态特征和16S rDNA序列分析鉴定该菌株属于Bacillus属. 对B659菌株进行紫外诱变，筛选得到酶活提高13.9%且稳定遗传的突变菌株G3-17；对G3-17菌株进一步进行微波诱变得到酶活较G3-17菌株高出11.6%且稳定遗传的突变菌株W1-40. 对B659菌株和W1-40突变菌株进行发酵试验，72 h时W1-40菌株的酶活力达到645.2 U·mL-1，比B659菌株(517.9 U·mL-1)提高24.6%.
With self-made xylan as the only carbon source of primary screening medium，totally 60 strains which showed transparent zones and different morphology were screened from different marine samples. The shake flask fermentation results showed that 38 strains had xylanase-producing capabilities and strain B659 had the highest xylanase activity of 525.3 U·mL . Via morphological characteristics and 16S rDNA sequence analysis，strain B659 was identified as Bacillus. The stable mutant strain G3-17 with 13.9% enhancement of xylanase activity was screened from the UV mutagenesis of strain B659. A stable mutant strain W1-40 with 11.6% xylanase activity increase was obtained by microwave mutation and screening from strain G3-17. In 72 h fermentation of strain B659 and strain W1-40，the xylanase activity of latter (645.2 U·mL -1) achieved 24.6% elevation than the former(517.9 U·mL -1)