| Abstract: | When Bacillus polymyxa, a wild-type biotin auxotroph, is grown in biotin-deficient medium, a retardation of cell division and consequential cell elongation are the initial detectable consequences of limited biotin. Subsequent events in biotin-deficient cells include, in chronological order: inhibition of net ribonucleic acid (RNA) synthesis and a simultaneous arithmetical accumulation of protein; loss of net RNA, deoxyribonucleic acid, and protein synthesis; morphological aberration, death, and lysis. Incorporation studies employing 32P-phosphate and 14CO2 demonstrate an initial selective inhibition of net ribosomal RNA synthesis over that of ribosomal protein or total protein. Biotin could not be replaced by various extracts from which biotin had been removed, nor could osmotic stabilizers be found which could prevent lysis of the culture. |
