Effective comparison of yeast extracts from different sources on the growth of two Lactobacillus strains

The yeast extracts from five well-known companies were analyzed on their components and used as nitrogen source in medium respectively to investigate their effects on the growth and acid production of Lactobacillus helveticus and Lactobacillus rhamnosus. The results indicated that a Chinese yeast extract was better than three yeast extracts made by other countries for the growth of L. helveticus, but the four yeast extracts did not show obvious differences for the growth of L. rhamnosus. Therefore, it is feasible to use Chinese yeast extract instead of imported yeast extracts in lactic acid fermentation. Besides, the price of Chinese yeast extract is much lower than that of imported yeast extracts, which is very helpful for fermentation industry to lower the costs.