片烟产果胶酶细菌的鉴定及酶活测定

以果胶为碳源, 对津巴布韦片烟烟叶表面产果胶酶细菌进行分离, 采用16S rDNA限制性酶切片段长度多态性分析(ARDRA)和测序方法, 结合形态学、生理生化实验, 对所分离产果胶酶菌株进行鉴定, 同时研究培养时间、温度、起始pH、接种量对菌株产酶的影响。结果表明, 从津巴布韦片烟烟叶表面分离得到的产果胶酶菌株主要为芽孢杆菌属的枯草芽孢杆菌Bacillus subtilis和产碱菌属的粪产碱菌Alcaligenes faecalis。在所分离的菌株中, 枯草芽孢杆菌T10酶活力最高, 以6%的接种量, 在温度为35 °C、起始pH为7.5条件下培养48?56 h, 其果胶酶酶活为571 U/mg, 聚半乳糖醛酸裂解酶酶活为297 U/mg。

Identification of pectin-degrading strains isolated from tobacco strips and evaluation of its pectinase activity

Bacterial strains with pectinase enzyme activity were isolated from Zimbabwe tobacco strips using pectin as carbon source. ARDRA patterns of 16S rDNA combined with 16S rDNA sequence analysis, physiological and biochemical experiments were used to identify the isolated strains. Different conditions including incubating time, growth temperature, initial pH and inoculation quantity for the enzyme production were also studied. The results indicated that bacteria isolated from Zimbabwe tobacco strips with high pectin-degrading ability mainly belong to Bacillus subtilis (genus Bacillus) and Alcaligenes faecalis (genus Alcaligenes). Among these strains, Bacillus subtilis strain T10 possessed the highest pectinase activity (571 U/mg) and polygalacturonate lyase activity (297 U/mg) under its optimum enzyme fermantation conditions, which use 6% (V/V) culture fluid as the inoculum for enyme production in the pH 7.5 fermentation medium at 35 °C for 48?56 h.