Production of Metschnikowia pulcherrima by fermentation: effect of nitrogen and carbon sources on biomass
A. Ciavorella, D. Spadaro, A. Garibaldi and M.L. Gullino.
Journal of Plant Pathology Volume 90 (2, Supplement) August 2008, Book of Abstract, 9th International Congress of Plant Pathology, August 24-29, 2008 Torino, Italy,. 507 pages.
2008
บทคัดย่อ
Microbial antagonists have been developed as alternatives to chemicals, to reduce the amounts of fungicides and their residues on fruits. one strain of the yeast Metschnikowia pulcherrima showed effective biocontrol properties against the main postharvest pathogens on apple and kiwi fruits. Mass production of biocontrol agents is a focus of research and industrial development to obtain a product of high quality and low cost on a large scale.The aim of this work was to find the nitrogen and carbon sources producing, through fermentation technology, maximum biomass of M. pulcherrima with optimal antagonistic activity. Different nitrogen and carbon substrates were tested under different conditions of temperature and pH. A microbial concentration of 109 cfu/ml after 48 h of fermentation was obtained in a substrate containing one organic nitrogen source (yeast extract) and two organic carbon sources (sugars). The pH values during the fermentation gave the trend of the process: a neutral pH was typical of the initial inoculation step, whereas a basic pH suggested the end of the growth process, with an available growth range between pH 4 and 8. The best biocontrol on apples against Penicillium expansum and Botrytis cinerea was obtained when the yeast was grown in a sugar-enriched substrate.