Abstract
The purpose of this study was to improve the efficiency of the microbiological assays for biotin, niacin, and pantothenic acid by using lyophilized cells from Lactobacillus plantarum ATCC 8014. The use of lyophilized cells as an inoculum was assessed to avoid time-consuming processes like cell precultivation and washing. The authors also examined the effects of various protectants such as skim milk, sucrose, sorbitol, and trehalose on the assay. The viable cell counts of the lyophilized cells were found to be approximately equal for different protectants. The standard curves for biotin, niacin, and pantothenic acid concentrations obtained using lyophilized cells with sucrose and intact cells gave similar linear ranges. Furthermore, the measured vitamin concentrations of the standard reference material 3280 were in the range of the established values. Therefore, lyophilized cells with sucrose are potential alternative inocula for the turbidimetric method. This will increase the overall convenience associated with microbiological assays.
