海洋源高产葡萄糖氧化酶细菌的筛选和主要酶学性质

从海洋环境中筛选高产葡萄糖氧化酶的海洋细菌, 为生产葡萄糖氧化酶提供新的菌种资源。采集海泥、海水及珊瑚样品,采用亚甲基蓝平板显色培养的方法初步分离产酶细菌,再对分离菌株进行显色培养,挑选产酶优势菌株,用液态摇瓶发酵的方法测定优势菌株的产酶能力,然后检测温度及酸碱度对酶活性的影响,并对优势菌株进行形态鉴定、生化鉴定以及16S rDNA基因序列鉴定。从海泥样品中初筛得到几株产葡萄糖氧化酶的细菌,其中菌株MS-4产酶活力最高,该菌在常规LB液体培养条件下葡萄糖氧化酶活力达到8.8 U·mL^-1;所产酶最适作用温度为14 ℃,最适pH为7.0,在25 ℃以下活性稳定;经过综合鉴定MS-4是蜡状芽孢杆菌,其中生化鉴定和基因序列鉴定的结果显示,该菌与蜡状芽孢杆菌的相似度分别为98.8%和100%。实验结果说明,MS-4具有相对较高的产葡萄糖氧化酶能力,可作为低温食品保鲜用葡萄糖氧化酶的生产用菌进行开发和研究。

Screening and main enzymatic property of high-producing glucose oxidase bacteria from marine environment

In order to gain high-producing glucose oxidase bacteria from marine environment and provide new strains for glucose oxidase manufacture, producing glucose oxidase bacteria was separated with coloration culture method using methylene blue medium in Petri dish from sea mud, sea water and coral, the dominant producing glucose oxidase bacteria among them was screened with being coloration cultivated again, and it's producing glucose oxidase ability was measured with shaking liquid fermentation, and influence of pH and temperature on enzymatic activity were checked, afterwards it was identified in morphological, biochemical and 16S rDNA sequences. The results showed that several strains producing glucose oxidase were separated from sea mud, of which MS-4 was the highest producing glucose oxidase bacteria, it secreted glucose oxidase in fermentation fluid of normal LB culture reaching 8.8 U·mL^-1, and the glucose oxidase best fit act temperature was 14 ℃, pH was 7.0,and stability was maintained below 25 ℃. Synthesize identification showed that MS-4 was Bacillus cereus, the similarity of biochemical and 16S rDNA sequences were 98.8% and 100%, respectively. The experimental results indicated MS-4 was relatively high-producing glucose oxidase marine bacteria, and it could be studied and developed as a bacteria that produce glucose oxidase which could be used in food fresh keeping at low temperature.