马铃薯块茎蛾肠道细菌分离鉴定及其对植物源大分子化合物的降解作用

摘要

In order to study the cultural bacteria community structure in the larval gut of potato tuber moth,and its relationship with the feeding characteristics.The bacteria in the 4th instar larve gut of the potato tuber moth was isolated on the beef peptone medium,bacteria were identified using the 16S rDNA sequence,the biodegradation activity for plant based macromolecular compounds including amylum,fibre,xylan and pectin was evaluated using the enzyme assay culture techniques.The results showed that ten species of bacteria belonging to seven genera were isolated form the gut of the 4th instar larvae of Phthorimaea operculella (Zeller),those bacteria were Acinetobacte,Staphylococcus,Enterobacter,Arthrobacter,Sphingobacterium,Klebsiella,Tsukamurella and Stenotrophomonas.The Sphingobacterium strain LZD10,Staphylococcus strain LZN13 and Arthrobacter strain HZN9 can degrading the amylum,but the macromolecular of cellulose,xylan and pectin can't be degraded by those gut bacteria.Other 7 strains can't degrade the amylum,fibre,xylan and pectin.The study showed that there were the amylum degrading bacteria in the 4th instar larval gut of the potato tuber moth,this study will provide a theoretical base for the further study on feeding potato tuber feeing mechanisms of potato tuber moth.%为弄清马铃薯块茎蛾肠道可培养细菌的群落结构及其功能.本研究采用牛肉膏蛋白胨培养基,对马铃薯块茎蛾4龄幼虫肠道细菌进行了分离培养,采用16S rDNA序列对各菌株进行种属鉴定,并采用酶鉴定培养基法测定了肠道各细菌对淀粉、纤维素、木聚糖和果胶等植物源大分子物质的降解作用.从马铃薯块茎蛾肠道内共分离到细菌8属10种,分别为不动杆菌属Acinetobacte、葡萄球菌属Staphylococcus、肠杆菌属Enterobacter、节细菌属Arthrobacter、鞘氨醇杆菌属Sphingobacterium、寡养单胞菌属Stenotrophomonas、束村氏菌属Tsukamurella和克雷白氏杆菌属Klebsiella.其中仅鞘氨醇杆菌属菌株LZD10、阿氏节杆菌属菌株LZN13、烟草节杆菌属菌株HZN9对淀粉具有明显的降解作用,但对纤维素、木聚糖和果胶无降解作用,而其余菌株对4种化合物均无降解作用.该研究结果将为深入研究马铃薯块茎蛾对马铃薯块茎的食物适应机制及防治提供理论依据.