Untersuchungen über Vermehrung und Zellstruktur von Milchsäurebakterien in Kefirkörnern

Abstract

Summary The methods of multiplication of lactic acid bacteria, present in the composition of kefir grains, were studied and their intracellular structure was determined, using an electron transmission microscope. The conducted observations allowed to state that lactic acid bacteria appeared in kefir grains in round forms (cocci and streptococci) and in a shape of shorter or longer rods (rods and bacilli). In uranyl acetate-stained ultra-thin specimens from kefir grains, two methods of multiplication were stated, i.e., by division and by gemmation of the cells. Depending on the culture conditions of kefir grains, from club-shaped or rod-shaped forms, the spherical cells may be produced on the way of division or gemmation and, vice versa, by the elongation of cocci, the cells in a shape of rods or bacilli may be formed what is their characteristic feature. Besides it, these bacteria possess a very delicate cell wall, therefore they create the additional carbohydrate-protein membrane which protects them against the environment and this is their second characteristic feature, distinguishing them from other microorganisms what was stated in the ultrathin specimens studied in the electron transmission microscope.