Study on the fermentation conditions of glutathione produced by Candida utilis

The fermentation conditions of GSH produced by Candida utilis were studied, the effects of extraction methods, medium component and the glucose feeding on production of GSH were investigated. The optimal conditions were obtained as follows: ethanol method was chosen as the extraction method of intracellular GSH by screening.The yeast extract powder and ammonium sulfate had the greatest effect, especially, the yield reached25.48mg /g by addition of ammonium sulfate as nitrogen source. Addition volume of glucose was 16mL and the optimal feeding time was 10h.Under such conditions, the bacteria's cell dry weight was 8.14g /L, the glutathione yield was 113.45mg /L by shake flask culture, which was 2.89 fold improvement over that of the initial condition.