Submitted to: United States of America and Mexico Symposium
Publication Type: Abstract Only
Publication Acceptance Date: July 6, 2007
Publication Date: July 6, 2007
Citation: Jackson, M.A. 2007. Identifying fungal bioinsecticides that are suitable for production using liquid culture fermentation [abstract]. United States of America and Mexico Symposium. Per MAJ: This abstract was given to the meeting attendees without a page number. Technical Abstract: The lack of suitable methods for economically producing stable, effective fungal propagules continues to impede the commercial use of bioinsecticides. Hundreds of fungi have shown excellent potential for use as bioinsecticides principally because they are able to actively infect and kill their insect host. While this ability to infect and kill an insect host is a distinct advantage, the requirement for infection has innate limitations. An understanding of the environment in which the insect pest must be controlled, and therefore infected, and of the application techniques commonly used for delivery of insect control measures will guide the selection of the desired fungal propagule. The formation of a fungal propagule that is viable, stable, and efficacious in the environment in which it will be used must be addressed during the production and stabilization process. While the production of fungal conidia using solid-substrate fermentation is commonly practiced, this method suffers from high-labor costs, quality control concerns, scale-up problems, and propagule efficacy issues. For use as a foliar spray or “contact” bioinsecticide, liquid culture-produced fungal propagules that are yeasts or yeast-like are advantageous. Since yeast-like propagules such as blastospores are vegetative propagules, fermentation times are reduced, yields can be high, and these vegetative propagules tend to germinate more rapidly than conidia upon rehydration. The potential to control soil-borne insects is greatly enhanced if the fungal propagule produced will persist in the soil environment or persist as a formulated granule in the soil. Secondary conidiation would also be a beneficial trait. To demonstrate how nutritional factors present during liquid culture fermentation can be used to regulate fungal propagule formation, yield, and "fitness," results from our studies with the bioinsecticide Paecilomyces fumosoroseus, and the bioherbicides Colletotrichum truncatum and Mycoleptodiscus terrestris will be presented.