富产几丁质酶的链霉菌菌株筛选及其产酶条件优化

Screening of Chitinase-Production Streptomyces Strain and Optimization of Fermentation Condition

本研究旨在从土壤中筛选能产生几丁质酶的菌株,通过优化产酶条件提高菌株酶活,为获得新的生防菌株及防治植物病害奠定基础。从土壤中共筛选出73株不同菌株,其中产几丁质酶活最高的菌株酶活达0.795U·m L-1,经形态学、生理生化及分子生物学特征分析,鉴定其为酒红色链霉菌(Streptomyces vinaceus),命名为Streptomyces vinaceus S7。通过单因素法和正交试验设计优化产酶条件,优化之后,当玉米糊精和大豆蛋白胨添加量分别为10g·L-1,温度35℃,接种量10%,装液量50m L,在此条件下培养4d,酶活达到2.25 U·m L-1,比优化前提高1.83倍。该菌株几丁质酶活较高,有望应用于防治植物病害方面。

The research was to get a new strain and control plant diseases through screening of the chitinase-production strain from the soil and optimization of fermentation conditions. 73 strains were isolated, with highest initial chitinase activity of 0.795U·m L-1. The strain was identified as Streptomyces vinaceus S7 based on its morphology characters, biochemical characteristics and 16 S r DNA sequence. The fermentation medium and fermentation conditions were optimised through single factor method and orthogonal experiment.The optimal medium was obtained as: maize dextrin 10 g·L-1, soya peptone 10 g·L-1, and the optimum fermentation condition was 35 ℃ and cultured for 4d with 10% of inoculation and 50 m L of liquid volume. The chitinase activity increased to 2.25 U·m L-1after the optimization, 1.83-fold of the initial chitinase activity. The results showed that the strain with high chintinase activity is possible for the control of plant diseases.