Year: 2011
Type: dissertation
Abstract: Saccharomyces cerevisiae is commonly associated with the wine industry.However, this yeast was also isolated from soils not associated with vines.Despite the fact that S. cerevisiae is not perceived as an autochthonous soil yeast, its interaction with other soil microbiota suggests the contrary.Aside from a few in vitro studies, the fate of S. cerevisiae in soil is largely unknown.This may partly be ascribed to the lack of reliable methods to enumerate fermentative yeasts in soil.Consequently, we evaluated an enumeration procedure for fermentative yeasts in soil, whereby yeast malt extract (YM) agar plates containing selective agents, were incubated in anaerobic jars before the colonies were enumerated.This procedure proved to be selective for fermentative yeasts, such as industrial strains of S. cerevisiae.We then commenced studying the growth and survival of S. cerevisiae in soil differing in moisture content and nutrient levels, using S. cerevisiae strain S92 and the genetically modified strain S. cerevisiae ML01, as well as two autochthonous soil yeasts, Cryptococcus laurentii and Cryptococcus podzolicus.The yeast strains were each inoculated into three series of microcosms containing sterile soil with a moisture content of ca.30% (v/w), a moisture content of ca.15% (v/w), or a moisture content of ca.30% supplemented with References
Author: Reinhard Bester
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
Funder: National Research Foundation
OpenAlex ID: W2115236450