蠟蚧輪枝菌(Verticillium lecanii)為昆蟲病原真菌,寄生在粉蝨及蚜蟲等農業害蟲上,也是在生物性農藥中很早被開發出來的微生物殺蟲劑。其殺蟲效果與孢子產量有著密不可分的關係,故培養量多且高活性之孢子對於農業上害蟲之防治有其研究空間。 本研究之主要目的有:尋找各種發酵條件下產孢之最佳誘發條件,進而擴大化生產;其次為了解在固態發酵中之熱平衡,從培養基中探討發酵熱的變化,利用熱力學之數學方式計算出精確的數值,以便在之後擴大化生產能夠有效的解決發酵熱問題,增加產率。 在太空包發酵條件下,產孢之最佳誘發條件為30 °C ,2天,總孢子數為1.76×1010 spore/ g。孢子活性(發芽率) 可達到61.46%。10 liter發酵槽發酵條件下之最適誘發產孢條件為28°C (3天),總孢子數為5.49×109 spore/ g,其孢子活性(發芽率) 可達到78.76%。 固態發酵中之熱平衡中,藉著蠟蚧輪枝菌在發酵週期中之溫度變化,與培養基測得的Cp值,可計算出發酵週期中的發酵熱變化。培養基之Cp值為0.5716卡/克/°C。
Verticillium lecanii was generally recognized as a pathogenic fungus that is widely spread in nature and is parasitic in many insects of agricultural concerns. The fungus has drawn many interests of developing into microbial insecticide in the biological agricultural chemical industry. The intentions of this research are: optimizing the fermentation conditions for spore production, finding a practical method for controlling the sporulation in order to maintain the viability, and investigating the mass and heat balance of the solid state fermentation. For cultures in plastic pouches, induction of sporulation at 30°C for 2 days,at the end of fermentation, spore production of 1.76×1010 spore/g was obtained. The germination rate was 61.46%. For cultures in a 10 liter fermentor, induction of sporulation at 28