粉红粘帚霉固体发酵孢子生长动力学及新型固体发酵反应器研究

Fungal biocontrol agents have shown good potential for control of insect pests and suppression of plant diseases. The non-pathogenic, saprophytic fungus Clonostachys rosea (syn. Gliocladium roseum) is one of the most powerful BCAs, as shown in control of Botrytis cinerea (gray mold) on strawberry, tomato, rose, and eucalyptus and Rhizoctonia solani in a tobacco float system and Fusarium spp. on cucumber plants and wheat plants. C. rosea has a high and versatile ecological fitness and is frequently found in cultivated soils, degrading phytotoxic phenolic acids and in aerial plant structures The success of C. rosea as a biocontrol agent involves diverse modes of action, including nutrient competition in wounded tissue, hyperparasitism and induction of resistance in the host plant. The production of fungal BCAs is still one of the major constraints for their large-scale use and commercialization. However, few studies focused on establishing optimized methods for upscale production of C. rosea spore. Spores are generally produced by solid state fermentations (SSF) on wheat grains. In our best known ,there is no report for investigation on kinetics of spore growth. It is indispensable to develop a novel solid-state fermentor and investigate methods for increasing both the spore yield and the shelf-life while reducing their production costs. The objective of this research was to study kinetics of spore growth and develop the modeling of spore growth and also to develop the novel fermentor and optimize the conditions for spore production by C. rosea in solid-state fermentation using response surface methodology (RSM) in order to increase previously reported yields for C. rosea while reducing the cost of production and/or time requirement. Our previously work shows that the optimized spore yield was increased by 41.8% and the fermentation time was shortened to 7-9 days. The present work will develop a kinetics modeling of spore growth and the novel solid-fermentation reactor and, also increase in C. rosea spores production and decrease in fermentation time were achieved by optimizing the important parameters. The results obtained will promote the industrialization of spore production by C. rosea in China.

生物农药对于我国农产品安全生产意义重大，粉红粘帚霉孢子是固体发酵生产的生物农药，但现有固体发酵反应器生产孢子效率低，且未见研究孢子生长动力学的报道。本课题提出一种新型固体发酵反应器，开展粉红粘帚霉分生孢子和厚垣孢子固体发酵生长动力学研究，进行孢子生长动力学实验，提出并建立2段式孢子生长动力学模型，模型包含最佳塑料膜开孔率、最佳料层温度、最佳料层初始含水量、最佳料层厚度为参数，可为固体发酵反应器的最优设计及操作提供理论支持。研发一种顶部、底部均透光的低成本新型固体发酵反应器，料层由带孔塑料膜包裹，通过改变开孔率可以调节料层含水量使其处于最佳孢子生长状态；研究精确搅拌（搅拌强度、搅拌次数及搅拌时机），以消除料层板结、改善氧传递、增加孢子生长面，可望大幅度提高孢子产率。前期工作表明，采用新型反应器的分生孢子产率较国外产率高出41.6％，本成果将有力推进粉红粘帚霉在我国的产业化进程。

生物农药对于我国农产品安全生产意义重大，粉红粘帚霉孢子是固体发酵生产的生物农药，但现有固体发酵反应器生产孢子效率低，研究孢子生长动力学对孢子生产具有重要理论意义。本项目开展了粉红粘帚霉固体发酵孢子生长动力学和新型固体发酵反应器实验研究，研发出一种顶部、底部均透光的低成本新型固体发酵反应器，提出并建立了2段式孢子生长动力学模型，模型计算值与实验值很好拟合，拟合值与实验值的平均偏差为3.18％。模型包含最佳塑料膜开孔率、最佳料层温度、最佳料层初始含水量、最佳料层厚度为参数，可为固体发酵反应器的最优设计及操作提供理论支持。目前尚未见相关孢子生长动力学模型的报道。新型固体发酵反应器可以提供2倍于传统反应器的孢子生长面，通过改变塑料膜开孔率可以调节料层含水量使其处于最佳孢子生长状态；研究结果表明，精确搅拌可以以消除料层板结、改善氧传递、大幅度增加孢子生长面，从而大幅度提高孢子产率。新型固体反应器的孢子产率为3.360×1010 (孢子/gDM)，为传统固体发酵反应器孢子产率的10倍。本成果将有力推进粉红粘帚霉在我国的产业化进程。.在国外期刊发表论文2篇，影响因子分别为2.485和1.8，获得中国发明专利一项。