Producing Saccharomyces cerevisiae yeast extract from winery spent yeast biomass

Abstract

Relying upon the dynamic fermentation capacities along with alcoholic tolerant characteristics, Saccharomyces cerevisiae strains are better known and have been widely studied in bread, brewery production, and winemaking. In addition, S. cerevisiae has played a pivotal role in yeast extract production for use in food and microbial media as a nutrient source especially. This project used a simple mechanical method on the new yeast source - winery spent yeast, a byproduct of alcoholic fermentation process, to produce yeast extract. The results showed that the yeast extract with optimal protein and nucleic acid content was obtained when spent yeast in water (1:4, g/mL) was sterilized at 110°C for 20 minutes using autoclave. Produced yeast extract exhibited high efficiency on bacterial growth including Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) that were similar to some commercials. As such, we have been successful in producing yeast extract using a temperature-pressure method on winery spent yeast.