柞蚕肠道菌群分析及产酶菌的筛选与鉴定

 【目的】研究柞蚕肠道菌群结构及产酶菌，探寻具有新的生理功能的微生物，用于研制微生态制剂，以提高柞蚕生产的叶丝转化率及抗病能力。【方法】采用培养法分离柞树叶饲喂的5龄柞蚕幼虫肠道细菌，通过生理生化特性结合16S rDNA系统发育分析，对其肠道细菌群落类型进行鉴定，采用筛选培养基筛选产纤维素酶、蛋白酶、脂肪酶的菌株。【结果】获得的柞蚕肠道菌有芽孢杆菌、葡萄球菌、肠杆菌，其中以芽孢杆菌为主要菌群。芽孢杆菌是肠道菌中产纤维素酶、蛋白酶的主要菌群；葡萄球菌产蛋白酶能力较弱；肠杆菌不产酶。【结论】柞蚕肠道菌与家蚕肠道菌群结构相似，筛选出的产酶菌活性较高，可以制备微生态制剂用于蚕业生产。

Analysis of Bacterial Community and Screening and Identification of Enzyme-Producing Bacteria in Intestine of Antheraea pernyi

【Objective】The objective of this study is to isolate and identify bacterial community and enzyme-producing bacteria in intestine of Antheraea pernyi larvae and to develop microecological agents for increasing leaf-silk conversation rate and disease resistance. 【Method】Bacteria were isolated from intestine of fifth instars Antheraea pernyi larvae reared on oak leaves by isolated culture. Intestinal bacterial community was identified according to physiological and biochemical characteristics and phylogenetic analysis based on 16S rDNA sequences. Cellulase, protease, lipase-producing strains were screened on selective medium. 【Result】The intestinal bacteria isolated from Antheraea pernyi larvae belong to Bacillus, Staphylococcus and Enterobacter. Among them, Bacillus is the main bacteria and the main enzyme-producing bacteria which could produce cellulase and protease, Staphylococcus could produce protease weakly, Enterobacter couldn’t produce enzyme.【Conclusion】Intestinal bacteria community of Antheraea pernyi was similar to that of Bombyx mori, which could be developed as microecological agents in sericulture for the enzyme-producing strains exhibiting high activity.