拟康宁木霉T-51的固体发酵参数优化

Optimization of solid-state fermentation parameters for the biocontrol strain Trichoderma koningiopsis T-51

摘要:

【背景】 木霉是一类应用广泛的植物病害生防真菌。拟康宁木霉(Trichoderma koningiopsis) T-51是一株能够促进植物生长、诱导植物系统抗性、对多种植物病害有良好的防治效果的优秀生防菌株，具有较好的应用前景。【目的】 研究并优化拟康宁木霉T-51分生孢子的固体发酵技术，提高菌株T-51的产孢量，为该菌株的大规模生产提供理论参考。【方法】 采用单因素试验结合响应面法，筛选菌株T-51适宜的发酵基质，分析优化固体发酵的水分含量、发酵时长、接种浓度，以及碳氮源成分和比例等因素。【结果】 通过对不同固体发酵基质筛选发现，使用单一稻壳作为发酵基质的产孢效果最好，水分含量为75%且发酵时间延长至11 d能够显著提高产孢量，接种浓度在1×10⁶CFU/mL时产孢量更高，高浓度孢子液(1×10⁸ CFU/mL)接种则产孢量下降；稻壳基质中最适宜菌株T-51产孢的碳氮源为葡萄糖和硫酸铵。通过响应面法分析得到最佳发酵条件：水分含量79.5%，发酵时长11 d，接种浓度1×10⁶ CFU/ml，最佳碳氮源成分比例：葡萄糖2.6%，乳糖0.75%和硫酸铵5%，于此优化条件下菌株T-51预测最高产孢量为7.76×10⁹ CFU/g，实际产孢量为7.83×10⁹ CFU/g。【结论】 建立了基于稻壳基质的菌株T-51高效固体发酵技术，使菌株T-51的产孢量能够满足田间应用的需求，降低生产成本，为菌株T-51未来在田间的规模化应用提供了理论基础。

Abstract:

[Background] Trichoderma spp. have been widely used for controlling plant diseases. Trichoderma koningiopsis T-51, an effective biocontrol strain, is capable of promoting plant growth, inducing plant systemic resistance, and controlling plant diseases, demonstrating a promising prospect for practical applications. [Objective] To study and optimize the solid-state fermentation technology of T. koningiopsis T-51 for improving the spore production, and provide a theoretical reference for the large-scale production of this strain. [Methods] Single-factor experiments and response surface methodology were employed to screen the suitable fermentation substrate for strain T-51 and optimize the key fermentation factors including water content, fermentation duration, inoculation concentration, and carbon and nitrogen source composition. [Results] With rice husk as the fermentation substrate, the strain demonstrated the highest spore production. The water content of 75% and fermentation duration of 11 days significantly increased the spore production. In addition, an inoculation concentration of 1×10⁶ CFU/mL exhibited higher spore production, while the inoculation concentration of 1×10⁸ CFU/mL showed a decrease in sporulation. Glucose and ammonium sulfate were identified as the optimal carbon and nitrogen sources, respectively, for the spore production of strain T-51 with rice husk as the substrate. The fermentation parameters were optimized by the response surface methodology as water content of 79.5%, fermentation duration of 11 days, inoculation concentration of 1×10⁶ CFU/mL, 2.6% glucose, 0.75% lactose, and 5% ammonium sulfate. Under these optimized conditions, strain T-51 was predicted to achieve the maximum spore production of 7.76×10⁹ CFU/g, and the measured value was 7.83×10⁹ CFU/g. [Conclusion] This study has successfully established an efficient solid-state fermentation technology for strain T-51 with rice husk as the substrate, allowing adequate sporulation for field applications with reduced production costs. This study provided a theoretical basis for the future large-scale application of strain T-51 in the field.