Susceptibility of selected commercial yeasts to autolysis for yeast extract production

Abstract

Ten yeasts comprising nine Saccharomyces cerevisiae and one S.carlsbergensis were assessed for their susceptibility to autolysis for yeast extract production. The work was done in the period April to June, 2000. Each strain was autolysed in distilled water (pH 6.5) at 45°C for 6 hours and dry weight losses, release of proteins into the medium and pH monitored. Dry weight losses appeared to be the most discriminatory evidence of autolysis. Saccharomyces cerevisiae Y1045 and Y58 showed 25.0 percent and 23.9 percent dry weight losses respectively; the other strains autolysed less rapidly. Lactobacillus bulgaricusgrew comparably well in a basal medium supplemented with 5 percent (v/v) of S. cerevisiae Y1045 autolyzate, and in the same basal medium supplemented with 0.5 percent (w/v) commercial yeast extract. The study showed that S. cerevisiae Y1045 has the potential for use in yeast extract production.