一株源于红树林根际土壤的枯草芽孢杆菌产淀粉酶条件及酶学性质研究

Amylase-producing Conditions and Enzymatic Properties of Bacillus subtilis from Mangrove Rhizosphere Soil

从三亚红树林保护区中筛选出一株产淀粉酶枯草芽孢杆菌,通过改变培养温度、初始p H值和盐浓度等因素研究该菌株的最适产酶条件,同时也分析了该菌株所产粗酶的热稳定性及p H稳定性。结果表明:该菌株属于中温产酶菌,产淀粉酶的最适温度为40℃,最适p H值为8,盐耐受能力可达到4%。酶学性质分析发现,该菌株产生的淀粉酶在40℃保温150 min后仍有70%以上的相对酶活力,在p H为9的环境中孵育1 h,相对酶活力可达到90%以上。这些结果表明,该产淀粉酶菌株对热带地区海水环境具有较好的适应性,其作为消化酶类饲料添加剂具有广阔的应用前景。

A Bacillus subtilis strain which could produce amylase was isolated from mangrove rhizosphere soil in Sanya. The effects of culture conditions on the enzyme producing ability of strain were studied with different culture temperature, initial p H and salt concentration. In addition, The properties of amylase excreted by this strain were analyzed by the thermal stability and p H stability. The results showed that the strain was belonged to the mesophilic enzyme producing bacteria, the amylase-producing optimum temperature was 40℃, the optimal p H value was 8, and the salt tolerance ability could reach 4%. The study on enzymatic properties showed that the amylase produced by this strain was still 70% relative enzyme activity after 150 min at 40℃, and the relative enzyme activity of the amylase could reach more than 90% after 1h in the p H=9 environment. It suggested that the amylase producing strain had better adaptability for tropical marine environment, and had broad application prospects as a digestive enzyme feed additive.