[Changes in the chemical composition of Bacillus popilliae vegetative cells in the course of their growth on a...

The growth, development and changes in the chemical composition of Bacillus popilliae cells were studied in the course of their growth on a liquid chemically defined medium containing casein hydrolysate, complex vitamin mixtures and glucose. Growth of the culture on this medium was accompanied with diauxia which could be registered by changes in the rate of growth and synthesis of the main cellular polymers (DNA, RNA, protein, phospholipids). The rate of protein synthesis correlated with the specific growth rate which was maximal when the reserve substances of the cells or the compounds of partly digested biomass were used. The rate of protein synthesis in the experiment depended mainly on the protein synthesizing activity of RNA rather than on its content in the cells. The low rates of growth and protein synthesis, which suggest that the growth of the culture is being interested with in the course of utilization of the components of the nutrient medium, may account for the absence of spore formation by this strain on the medium used.