Usage and formation of sulphur compounds

Abstract

Sulphur metabolism is important for all microorganisms as it helps them to produce sulphur amino acids needed for their growth. Yeast of the species Saccharomyces cerevisiae were mainly studied during the last two decades to gain a broad knowledge on their requirement for certain sulphur sources and to understand the effect of sulphur metabolism on their growth and fermentation activity as well as its link to nitrogen metabolism. Furthermore the interest was focused on sulphur containing intermediates and by-products that were synthesized during alcoholic fermentation of grape musts and which have a high impact on wine quality like sulphite and volatile sulphur compounds. Apart from intensive studies carried out by certain research groups to avoid the occurrence of off-flavours due to an increased production of objectionable volatile sulphur compounds from yeast metabolism, the research activities covered the contribution of yeast to the varietal aromas of certain varieties. Ongoing research is dealing with the sulphur metabolism of lactic acid bacteria during malolactic fermentation of wine and provides an insight into their contribution on the use and formation of sulphur compounds. This chapter gives an overview on the most important steps of sulphur research related to the activity of yeast and lactic acid bacteria during winemaking. © 2009 Springer-Verlag Berlin Heidelberg. All rights reserved.