Biochemical Changes and their Regulation during Spore Formation and Germination.
Final rept. 1 Feb 77-31 Jan 80,
CONNECTICUT UNIV HEALTH CENTER FARMINGTON DEPT OF BIOCHEMISTRY
Pagination or Media Count:
Metabolism of several important small molecules has been examined during sporulation and spore germination in Bacillus megaterium. These studies have indicated 1 the major known low molecular weight thioldisulfide in Bacillus species is Coenzyme A CoA 2 CoA in growing or sporulating cells is in either an acyl form or as the free thiol, but that in dormant spores about 75 is in a disulfide form with 50 in disulfide linkage to spore core proteins these disulfides are cleaved in the first minutes of spore germination 3 dormant spores contain an NADH-linked disulfide reductase which cleaves CoA disulfides. This enzyme is low or absent from log-phase or early sporulating cells, and appears during sporulation. It has no activity on cystine, glutathione or pantethine, and has highest activity on 4,4-phosphopantethine 4 Bacillus megaterium cells contain a very low level of cyclic GMP cGMP, but cGMP is not found in spores and it appears unlikely to be a modulator of sporulation, germination or outgrowth 5 The pH within dormant spores is about 6.3, a value which is independent of the external pH. However, early in spore germination the internal pH rises to 7.5 and 6 the key enzyme in regulation of 3-phosphoglycerate 3-PGA accumulation during sporulation, and its rapid utilization during spore germination and thus ATP production is PGA mutase.