一株拮抗葡萄灰霉病的嗜线虫致病杆菌发酵条件优化

【目的】分析单因素试验和响应面法优化嗜线虫致病杆菌(Xenorhabdus nematophila-ALL)对葡萄灰霉菌抑菌活性的发酵条件,提高拮抗菌(ALL)对灰葡萄孢菌丝的抑制率,为Xenorhabdus nematophila-ALL菌株发酵生产及生物防治应用奠定基础。【方法】以菌丝抑制率为指标,经菌丝生长速率法,单因素试验及Box-Behnken设计对菌株发酵条件进行优化,确定菌株最佳发酵抑制条件。【结果】最佳培养条件为培养基初始pH值改为7.12,装液量为56％,发酵培养时间为77 h。经验证的抑制率为87.70％,比优化之前提高了1.82倍。【结论】发酵条件优化有效提高了嗜线虫致病杆菌对葡萄灰霉菌的抑菌活性。

Study on the Optimization of Fermentation Conditions of a Xenorhabdus nematophila against Grape Gray Mold

【Objective】 This project aims to optimize the fermentation conditions for the antibacterial activity of Xenorhabdus nematophila-ALL (Xenorhabdus nematophila-ALL) strains against Botrytis cinerea through single factor test and response surface methodology in the hope of further increasing the inhibition rate of antagonistic bacteria against Botrytis cinerea hyphae and lay the relevant research foundation for the future large-scale fermentation production and biological control application of Xenorhabdus nematophila-ALL strains. 【Methods】 Using the mycelial growth rate method, taking the mycelial inhibition rate as an indicator, the Box-Behnken design was used to optimize the fermentation conditions of the strains through single factor and orthogonal experiments were conducted to determine the best inhibition conditions for the strains. 【Results】 The results showed that the optimal culture conditions were obtained by response surface analysis based on the single factor experiment: The initial pH of the medium was changed to 7.12, the bottling volume was 56％, and the fermentation culture time was 77h. The verified inhibition rate was 87.70％, which was 1.82 times higher than that before optimization. 【Conclusion】 The response surface optimization test effectively improves the antibacterial activity of Xenorhabdus nematophila.