摘要
【目的】优化比基尼链霉菌HD-087摇瓶发酵条件,提高菌株发酵液对黄瓜枯萎病菌HU-M的抑制率,并通过拮抗试验初步评价发酵液的抑菌作用效果。【方法】采用单因素筛选及正交试验对HD-087的发酵培养基和发酵条件进行优化。经发酵液处理后,光学显微镜观察HU-M菌丝形态和孢子萌发抑制率,测定HU-M菌丝电导率。【结果】改进的发酵培养基配方为:淀粉1.00%、黄豆粉0.80%、酵母粉0.12%、CaCO30.40%。对发酵条件的研究表明:pH为6.8,180 r/min、28°C条件下,250 mL三角瓶装液量为40 mL,接种1 mL种龄为2 d的种子,发酵5 d为最佳培养条件。抑菌结果表明,HD-087产抗菌物质能造成病原菌HU-M菌丝细胞质渗漏,菌丝畸形,分生孢子萌发受抑制,5倍发酵稀释液孢子抑制率达72.1%;除此之外还能引起菌丝电解质渗漏,造成菌丝细胞膜受损。【结论】优化后的摇瓶发酵条件能提高生防菌HD-087发酵液抑菌效果,并且发酵液可破坏细胞膜明显抑制病原菌HU-M生长,具有较大开发应用潜力。
[Objective] In order to improve the inhibitory rate of fermentation broth of Streptomyces bikiniensis strain HD-087 against Fusarium oxysporum strain HU-M, the shake-flask fermentation conditions of biocontrol agent HD-087 were optimized. Restraining effectiveness of broth towards HU-M has been tested at the same time. [Methods] The liquid fermentation medium and conditions of HD-087 were optimized by single factor experiments and orthogo-nal experiments. After inoculation with broth, HU-M hyphae morphology and germination of conidia were then examined under the light microscope, and the relative conductivity of HU-M hyphae was measured using a conductivity meter. [Results] The composition of the optimal medium was 1.00% （W/V） starch, 0.80% （W/V） soybean flour, 0.12% （W/V） yeast extract, 0.40% （W/V） CaCO3. The optimal fermentation conditions were the combination of temperature 28 °C, initial pH 6.8, 180 r/min, incubation time 5 d, 1 mL inoculum volume and medium volume 40 mL/250 mL. The result of antibacterial effect can be concluded as follows： abnor-mality of pathogen hyphae and leakage of cytoplasm after treated with broth; meanwhile the inhibitive rate to conidia germination reached 72.1% when the broth diluted by 5 times. In ad-dition to that, exosmosis of hyphae content, conductance rate increased. [Conclusion] All these changes indicate that optimal shake-flask fermentation conditions can improve the in-hibitory activity of HD-087 broth against F. oxysporum HU-M, and the broth has been proved efficient for suppression of HU-M by severely destroying cell membrane structure, it’s of great potential application value.
出处
《微生物学通报》
CAS
CSCD
北大核心
2013年第5期802-811,共10页
Microbiology China
基金
黑龙江省博士后资助经费项目(No.LBH-Z10009)
黑龙江省自然科学基金项目(No.C201203)
关键词
比基尼链霉菌
黄瓜枯萎病
发酵条件优化
生物防治
Streptomyces bikiniensis, Cucumber Fusarium wilt, Optimization of fermentation con-dition, Biocontrol
