Abstract: Cordyceps javanica MSC-F1 is a biocontrol fungus with significant pathogenicity against various pests such as Diaphorina citri and Panonychus citri. However, its industrialized application is hindered by high fermentation cost and imperfect fermentation processes. To enhance spore yield and reduce production cost, this study employed expanded polypropylene particles (EPP) as the primary inert carrier and optimized medium composition and culture conditions using single-factor and orthogonal test for high spore yield. The results indicated that the optimal basal medium consisted of a mixture of EPP and rice husk at a ratio of 4:1 (V/V), with a solid-to-liquid ratio of 1:1.2. Additionally, the basal medium was supplemented with 20% corn flour, 16% soybean meal, and 1.5% yeast extract. The optimal solid-state fermentation conditions were: cultivation temperature at 25 ℃, fermentation period for 9 days, inoculation size of 2%, and initial pH of 7.0. Under these optimized conditions, the spore yield increased 6.28 times compared to pre-optimization level. This study provides critical theoretical support for solid-state fermentation of Cordyceps javanica using EPP as inert carrier.

Key words: Cordyceps javanica, solid-state fermentation, expanded polypropylene, inert carrier