The Plant Pathology Journal ©The Korean Society of Plant Pathology Selection of KYC 3270, a Cellulolytic Myxobacteria of Sorangium cellulosum, against Several Phytopathogens and a Potential Biocontrol Agent against Gray Mold in Stored Fruit

bacteria consisting of 318 cellulolytic and 137 bacterio-lytic myxobacteria were isolated, which were then screen-ed for antifungal activity against the phytopathogens Botrytis cinerea, Colletotrichum acutatum, Penicillium sp., Pyricularia grisea, and Phytophthora capsici. 204 isolates had antifungal activity, causing both a clear zone due to blocked spore germination and inhibition of mycelial growth; most (199) were from cellulolytic (Sorangium cellulosum) and only five were from bac-teriolytic myxobacteria. B. cinerea, the best controlled among the five tested pathogens, had a unique group of antifungal isolates of myxobacterial extracts compared to the other pathogens ’ groups. Among seventy-nine bioactive myxobacteria, four isolates, KYC 3130, KYC 3247, KYC 3248 and KYC 3270, were selected and all were cellulolytic. Liquid culture filtrates of these four myxobacteria were applied to tomato, cherry tomato, strawberry, and kiwi fruits 5 h before inoculation with gray mold conidia; then the treated fruits were placed in an airtight container and the experiment was repeat-ed six to eight times. Incidence (%) of gray mold on fruit of the infected control treatment was 84−98%, whereas it was only 5−21 % after the KYC 3270 treat-ment. After KYC 3270 treatment of the four fruits, mold control was 79−95%, which was highest among the filtrates and statistically the same as treatment with fludioxonil, a registered chemical against gray mold of stored fruits