Three Different Targets for the Genetic Modification of Wine Yeast Strains Resulting in Improved Effectiveness of Bentonite Fining

Bentonite fining is used in the clarification of white wines to prevent protein haze. This treatment results in the loss of a significant portion of the wine itself, as well as aroma compounds important for the quality of white wines. Among other interesting effects on wine quality, yeast cell wall mannoproteins have been shown to stabilize wine against protein haze. A previous work showed that wine yeast strains engineered by deletion of KNR4 release increased amounts of mannoproteins and produce wines showing attenuated responses in protein haze tests. This paper describes the technological properties of several new recombinant wine yeast strains, deleted for genes involved in cell-wall biogenesis, as well as the regulatory gene KNR4. Stabilization of wines produced by three of the six recombinant strains analyzed required 20−40% less bentonite than those made with their nonrecombinant counterparts. The availability of multiple targets for genetically improving yeast mannoprotein release, as shown in this work, is relevant not only for genetic engineering of wine yeast but especially for the feasibility of genetically improving this character by classical methods of strain development such as random mutagenesis or sexual hybridization.

Bibliographic Details

Main Authors:	González Ramos, Daniel, Quirós Asensio, Manuel, González García, Ramón
Other Authors:	Ministerio de Ciencia e Innovación (España)
Format:	artículo biblioteca
Language:	English
Published:	American Chemical Society 2009
Subjects:	Wine yeast, Mannoproteins, Protein haze, Bentonite fining,
Online Access:	http://hdl.handle.net/10261/41051 http://dx.doi.org/10.13039/501100004837 http://dx.doi.org/10.13039/501100003086
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