家蚕肠道产蛋白酶菌株的分离与鉴定及其发酵条件  

Isolation and Identification of the Protease-producing Bacteria from Gut of Silkworm (Bombyx mori) and Its Suitable Fermentation Condition

作　　者：王在贵[1] 杨文静[1] 刘朝良[1] 朱保建[1] 魏国清[1] 邹昌瑞[1] 

机构地区：[1]安徽农业大学生命科学学院,合肥230036

出　　处：《农业生物技术学报》2011年第1期149-156,共8页Journal of Agricultural Biotechnology

基　　金：安徽省国际合作项目(No.08080703017);安徽省人才专项基金(No.2008Z022);安徽高校省级自然科学研究重点项目(No.KJ2009A031Z);现代农业产业技术体系建设专项资金资助资助

摘　　要：为探明家蚕肠道中产蛋白酶细菌的种类分布及其作用效果,本研究以家蚕(Bombyx mori)4龄幼虫肠道内容物为材料,采用牛肉膏蛋白胨培养基和酪蛋白培养基分离筛选产蛋白酶细菌菌株,利用16SrDNA序列分析鉴定其种属,并研究其产酶能力和产酶活力较高菌株的最适发酵条件。结果获得3株产蛋白酶菌株皓月NA1、951NA3和951NA6,均归属于不动杆菌属(Acinetobacter),其中皓月NA1号细菌产酶能力最强,最佳产酶量为29.5U/mL。以玉米粉10000mg/L、黄豆粉10000mg/L、MgSO4400mg/L、NaC115000mg/L和K2HPO41000mg/L作为发酵培养基成分,在35℃、起始pH9.0、装液量为80mL/150mL、180r/min振荡培养48h的优化发酵条件下,皓月NA1号细菌最大产酶量可达50U/m L。研究结果对家蚕肠道微生物的分布及肠道益生菌的作用效果调控有着十分重要的意义。To explore the species distribution and probiotics function of enzyme-producing bacteria in gut of the silkworm,protease-producing bacteria strains were isolated from the inclusion in 4th larval guts of the silkworm Bombyx mori by NA mediums and casein-NA mediums and 16 Sr DNA sequences were used to identify the species. Meanwhile,the enzyme producing activities of the three strains and optimum fermentation conditions of Haoyue NA1 strain were investigated. The results showed that three strains Haoyue NA1,951 NA3 and 951 NA6 belonged to Acinetobacter were isolated and confirmed. The maximum protease activity with 29.5 U/mL was found in Haoyue NA1 and the optimum fermentation conditions were corn powder 10 000 mg/L,soybean powder 10 000 mg/L,MgSO4 400 mg/L,NaC1 15 000 mg/L and K2HPO4 1 000 mg/L with a liquid volume of 80 mL in 150 mL bottol and cultured at 35 ℃,pH 9.0 under 180 r/min for 48 h. In this condition,the maximum protease activity produced by Haoyue NA1 reached 50 U/mL. This research can play an important role on the research of distribution of microrganisms in gut of the silkworm and on the control of the gut probiotics function.

关 键 词：家蚕 肠道细菌 蛋白酶 16SrDNA 发酵条件 

分 类 号：TQ925.2[轻工技术与工程—发酵工程]