Availability of essential vitamins and amino acids for Lactobacillus plantarum in cucumber fermentations.

Until recently, the only essential nutrient for the acid fermentation of cucumbers which had been investigated as such was sugar. Thus, Fabian and Wickerham (1935) noted that the addition of sucrose late in the fermentation resulted in an increase in the number of acid producing bacteria. However, Jones et al., (1940) and Veldhuis et al., (1941) demonstrated that while the addition of sucrose brought about an increase in the population of acid-forming bacteria, the titratable acidity formed in such brines was no higher than that in control lots. From these results it would appear that some other factor was limiting the amount of acidity formed. Costilow and Fabian (1953a) have shown that four isolates of Lactobacillus plantarum from cucumber fermentations all required at least three vitamins and six amino acids for rapid acid production. Therefore, these vitamins and amino acids must be present in fermenting brines in sufficient quantities for a desirable acid fermentation to occur. Rosen and Fabian (1953) have demonstrated the presence of biotin, niacin, and pantothenic acid in cucumbers and in cucumber brines. Their observations indicated that these three vitamins were present in brines in sufficient quantities throughout the fermentation for L. plantarum. However, considerable variation was noted in the biotin, niacin and pantothenic acid content of the juice from different varieties and from individual cucumbers. In addition, biotin concentrations were greatly affected by the growth of various brine organisms. No determinations on the amino acid content of either cucumbers or cucumber brines were made in this work. The purpose of this study was to determine whether the vitamins and amino acids essential for L. plantarum were available in cucumber brines; and, if so, how rapidly they became available and the concentrations which they attained.