Study on autolysis solution of waste yeasts used as a nutrition for acetic acid bacteria

In order to further decrease the production cost of acetic acid,the feasibility to use autolysis solution of waste yeasts as organic nitrogen source instead of yeast extract,was investigated.The influential factors for yeast autolysis were studied to optimize the autolysis conditions.The results indicated that the optimal autolysis conditions were as follows:water 200%,NaCl 3%,initial pH 7.0,autolysis temperature 50℃,and autolysis time 48h.Then the autolysis solution was used for shake culture of acetic acid bacteria.The results showed that the concentration of acetic acid bacteria and acetic acid were improved more than 54% and 10%,respectively,when yeast autolysis solution was used instead of yeast extract.Hence,the application of autolysis solution of discarded beer yeast possessed a promising prospect in acetic acid production when alcohol was used as raw material.