Ultrastructure of Lactobacillus fermentum during early and late growth phases and during thiamine deficiency.

Thin sections of exponentially growing and stationary-phase cells of L. fermentum from thiamine sufficient and thiamine deficient media were studied by electron microscopy. Compared to the exponential-phase cells the stationary-phase cells from both types of media had thicker cell walls and cross walls and fewer and smaller granules of storage material. Exponential-phase, thiamine deficient cells had rather thin cell walls and small mesosomes.