Question

He authors refer to a study by Linderholm et al. (2008), in which the authors tested all of the strains in the yeast deletion library for low H 2

​ S production on BiGGY agar. Only four strains of ∼6000 strains produced white colonies on this indicator agar, consistent with reduced or absent H2
S. Which genes were deleted in those strains? Hypothesize why these four genes turned up in the screen. Your answer: D) Why is the reduction of sulfite reductase, rather than its elimination, a better strategy for reducing hydrogen sulfide in wine?

Answer 1

Reducing sulfite reductase activity rather than eliminating it provides an optimal balance, lowering hydrogen sulfide in wine while maintaining yeast metabolic processes crucial for wine quality.

Step-by-step explanation:

The question centers on the rationale behind why reducing, rather than completely eliminating, sulfite reductase may be a better strategy for lowering hydrogen sulfide in wine production. Sulfite reductase is an enzyme directly responsible for converting sulfites to hydrogen sulfide (H2S), a compound that can impart undesirable aromas to wine.

A complete elimination of this enzyme may lead to unintended disruptions in yeast metabolism, as it plays a role in the sulfur assimilation pathway necessary for synthesizing essential cellular components. Therefore, a reduction rather than a complete elimination allows for a balance between reducing H2S production to acceptable levels without severely impacting yeast physiology and ultimately, wine quality. This approach can minimize negative effects on yeast viability and maintain the integrity of the fermentation process.