1株抑制土传病原菌且产纤维素酶芽胞杆菌筛选及产酶条件的研究

通过刚果红染色法和DNS分光光度法对6种芽胞杆菌分泌胞外纤维素酶进行筛选,再通过管碟法测试对5种病原菌的抑菌作用,得到1株芽胞杆菌（菌株编号为X-02）酶活达182.5 U/mL,而且对几种土传病害有抑制作用。并对其产酶发酵培养基碳源、氮源及初始pH、发酵温度、接种量、摇瓶转速和时间进行优化,结果显示该菌株最佳碳源是2%CMC-Na,其次是葡萄糖,二者产酶之差只为21 U/mL。考虑大量生产的成本和方便性（CMC-Na溶解慢）,选择葡萄糖为碳源,氮源为2.0%蛋白胨与酵母膏复合氮源,在pH值为8.0、温度37℃、接种量为2%、转速为180 r/m in、时间48 h条件下酶活达到391.0 U/mL酶液,比优化前提高了2.1倍。

Screening and Enzyme Producing Conditions of Bacillus Strain Inhibited against Soil Borne Pathogen and Produced Cellulase

A Bacillus strain(serial number X-02) was screened among six kinds of Bacillus that excrete extracellular cellulase were screened through DNS spectrophotometer and the Congo red staining,by testing with 5 kinds of pathogen for their inhibition with cup-plate method;and the enzyme activity was as high as 182.5 U/mL and had the inhibition against several soil borne pathogens.Later carbon source,nitrogen source and initial pH of its fermentation medium,temperature,inoculation quantity,rotation of shake flask a...