Unbalanced growth death due to depletion of Mn2+ in Brevibacterium ammoniagenes.
In the microbial conversion of added hypoxanthine to 5'-inosinic acid, Mn(2+) concentration in the growth medium is known to have a profound effect both on the yield of 5'-inosinic acid and the morphology of cells of Brevibacterium ammoniagenes. To elucidate the mechanism in which Mn(2+) was concerned with cell morphology and 5'-inosinic acid production, effects of Mn(2+) on the macromolecular synthesis were measured. It was found that Mn(2+) strongly governed deoxyribonucleic acid (DNA) synthesis and that, in the medium lacking Mn(2+), DNA synthesis was stopped at the level corresponding to one-fourth to one-third that in the medium supplemented with Mn(2+) (100 mug/liter). On the other hand, cellular ribonucleic acid and protein synthesis was quite indifferent to Mn(2+) concentration. Consequently, cells showed so-called "unbalanced growth death" after 10 hr of culture, losing the ability to form colonies while cell mass was increasing. The elongated cells turned into irregular forms (bulbous, club-shaped, etc.) which finally lysed. Two main reaction components in the conversion of hypoxanthine to 5'-inosinic acid, phosphoribosylpyrophosphate and hypoxanthine phosphoribosyltransferase, were liberated into the medium during lysis. The role of Mn(2+) in the synthesis of DNA and the role of the unbalanced growth death in the conversion of hypoxanthine to 5'-inosinic acid are discussed.
D001426:Bacterial Proteins / Q000096:biosynthesis; D001951:Brevibacterium / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D004269:DNA, Bacterial / Q000096:biosynthesis; D007042:Hypoxanthines / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000378:metabolism* / Q000494:pharmacology; D009705:Nucleosides / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism / Q000494:pharmacology; D010759:Phosphorus Isotopes; D012329:RNA, Bacterial / Q000096:biosynthesis; D014166:Transferases / Q000378:metabolism
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D007042:Hypoxanthines; D009705:Nucleosides; D010710:Phosphates; D010759:Phosphorus Isotopes; D012329:RNA, Bacterial; D008345:Manganese; D014166:Transferases; D008274:Magnesium