Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: October 5, 2010
Publication Date: October 25, 2010
Citation: Schisler, D.A., Slininger, P.J., Dunlap, C.A., Tugba, A. 2010. Proactive management of fermentation and formulation interactions to improve biocontrol product performance [abstract]. U.S./Israel Binational Agricultural Research and Development and International Society of Horticultural Sciences. p. 213-219. Technical Abstract: The key components of biocontrol product development—discovery, fermentation, and formulation—are interactively linked to each other and ultimately to product performance. To identify biocontrol agents suited for commercial development, our discovery programs utilize a cumulative ranking system that includes both a strain’s liquid culture process economics and efficacy. Antagonists of the pink rot pathogen Phytophthora erythroseptica displayed differing times of onset of unbalanced growth (signalled by the time of dissolved oxygen recovery in culture broths) useful in ranking strains based on growth kinetics. Fermentation protocols can be tailored to enhance strain efficacy, as seen in the selection of fungicide tolerant variants of yeast Cryptococcus flavescens OH 182.9, active against Fusarium head blight (FHB) of wheat. Cold adaptation during fermentation of OH 182.9 produces cells with improved hyperosmotic shock tolerance, membrane wall spring constants, stability during formulation, and efficacy compared to non-adapted strains. In other studies, we have obtained the efficacy advantages of microbial blend formulations by conducting cost-saving, mixed-strain fermentations of yeast and bacterial strains active against FHB and postharvest maladies of potatoes, respectively. Formulating biocontrol agents in broth supernatants can benefit or harm agent survival and will dictate fermentation optimization schemes. Retaining the polysaccharide marginalan produced in liquid culture by cells of biocontrol agent Pseudomonas fluorescens S11:P:12 enhanced the survival of rapidly dried cells. With the recent advent of cost-manageable genomic tools, further understanding of the complexity of linkages between fermentation and formulation seems assured and should result in more robust biocontrol products in the marketplace.