[Fine structure and culture characteristics of Lactobacillus plantarum]

The preparations of Lactobacillus plantarum 8-PA-3 cultures growing for 6, 8 and 10 hours were taken at the phase of exponential growth in a liquid malt-containing nutrient medium, and their ultrathin sections and replicas were studied after freeze-fracturing and etching by means of electron microscopy. The authors discuss the dynamics of development of structural-functional complexes in the cells, in particular, their membranous structures. Their morphogenesis is correlated with the functional requirements of the cells due to peculiarities of the population growth. The organization of the cytoplasmic membrane is noteworthy: many vesicles appear at the periphery of the protoplast and, probably, are involved in metabolic processes via a mechanism of the exocytosis type. Membranous structures of the nucleoidosome type extend gradually in the nuclear area, most intensively by the time when the exponential growth ceases. This phenomenon may be regarded as a response to the population being crowded under these conditions.