一株分离自北极海冰的产β-半乳糖苷酶的海单胞菌(Marinomonas sp. BSi20414)的筛选、鉴定和产酶条件研究

从北极海冰中分离筛选出一株产β-半乳糖苷酶的菌株BSi20414,经初步鉴定,该菌株归属于海单胞属(Marinomonas),命名为Marinomonas sp.BS120414.对该菌株的产酶条件实验表明,最适产酶条件为:30℃,180 rpm摇瓶培养96 h,培养基中加1.5%(w/v)乳糖,初始pH 7.0,接种...

PRELIMINARY STUDIES ON THE SCREENING, IDENTIFICATION AND OPTIMUM FERMENTATIVE CONDITIONS OF A STRAIN MARINOMONAS SP.BS120414 ISOLATED FROM ARCTIC SEA ICE PRODUCING β-GALACTOSIDASE

A strain BSi20414 with higher β-galactosidase activity was isolated from Arctic sea ice. Based on its Physiological and biochemical characteristics and 16S rDNA sequence, it was identified as Marinomonas sp. BSi20414. A series of the detail experiments on the conditions of β-galactosidase production were conducted and the results showed that the optimal fermentation conditions for enzyme production were: 30℃，1.5% (w/v) lactose, initial pH 7.0，Inoculum amount 3%，80 mL fermentative medium in 500 mL flask, 180 rpm for 96 hrs. Under these conditions, the enzyme activity of 1.01 U / mL in the second screening stage increased to 2.92 U / mL. Preliminary experiments showed that the optimal reaction temperature of the crude enzyme on ONPG substrate was 60 ℃. This Result suggested that this cold adapted strain Marinomonas sp. BSi20414 may be have a characteristic of producing high-temperature enzyme.