Growth and Sporulation of Bacillus subtilis Mutants Blocked in the Pyruvate Dehydrogenase Complex

摘要: Two “ACE” mutants of Bacillus subtilis which require acetate for growth on glucose minimal medium have been isolated. They do not grow with acetoin, 2,3-butanediol, fatty acids, isoleucine, lipoic acid, malic pyruvic succinic thiamine, or valine, but respond somewhat to glutamate citrate. The lack the activity pyruvate dehydrogenase complex; they excrete and later acetoin. in nutrient sporulation (NSMP) one-half normal turbidity sporulate subsequently. When is added NSMP (at optimal concentration 0.07 m), ACE then normally. Growth restored upon addition citrate, glucose, glutamate, glycerol, ribose, malate, oxaloacetate, pyruvate, several other compounds. After has stopped, incorporate uracil only at a very low rate, can be increased by acetate, glutamate. Furthermore, metabolism acetoin prevented after stopped acetate. All these results explained reduced nicotinamide adenine dinucleotide (NADH) resulting from deficiency acetylcoenzyme A. In fact, had NADH was borderline measurability, whereas it significantly glucose. growing standard strain contains, same bacterial turbidity, least 20 times more (230 pmole/optical density unit 600 nm) than nongrowing mutants. isolated spores, obtained plus initiated germinate presence either l-alanine combination l-asparagine, fructose, potassium; required no effect.