Patagonian Antagonist Yeasts for Food Biopreservation

VILLALBA MARÍA L.; LUTZ MARÍA C.; LOPEZ SOFIA NATIVIDAD; PILDAIN MARÍA BELÉN; SANGORRÍN MARCELA

Biology and Biotechnology of Patagonian Microorganisms

Springer International Publishing

Año: 2016; p. 301 - 323

Worldwide, microbial growth destroys large amounts of various products,causing yield losses in the agronomical and biotechnological industries.Traditionally, biocides have been used to manage these problems, but differentdisadvantages such as the establishment of resistant strains and the suppression ofnatural competitors have made alternatives such as biological control necessary.After harvest, many fruits are kept in cold storage to prolong their availability andshelf life. Often, this requires the application of a chemical fungicide to preventpostharvest decay from decay fungi. An alternative approach for preventing postharvestfungal decay during storage could be based on the treatment of the commoditywith antagonistic yeasts. In this regard, the use of cold-adapted yeasts mayoffer a distinct advantage. Numerous cold-adapted yeasts species have been isolatedfrom artifi cial cold environments, as well as cold-stored fruits. Recently, weisolated and identifi ed epiphytic yeasts during the cold postharvest storage of pearsand fi ne fruits from packinghouses in Argentinean Patagonia, and we tested theireffi cacy in controlling the postharvest diseases of different fruits caused by severalpathogens. Additionally, killer yeasts as producers of mycocins or killer toxins thatcan neutralize the activities of spoilage yeasts in wines represent an interestingbiocontrol strategy. Several screening studies focused to determine the occurrenceof killer yeasts in winemaking environments have been carried out, and they havedemonstrated the presence of killer phenotypes in yeasts from wines, cellar surfaces,and winery equipment. In previous studies carried out in our laboratory,most yeasts isolated from spontaneously fermenting grape musts evidenced killercharacter. These studies provide an exceptional source of potential antagonistyeasts to be used in biocontrol of undesired microorganisms in wine. Nonetheless,it is necessary to continue to identify new potential microorganisms and to developa better understanding of the biology of yeast biocontrol systems to increase thepotential of postharvest biocontrol as a viable alternative to synthetic postharvestfungicides and chemical preservatives against wine spoilage yeast.