Mil'ko E S, Krasil'nikova E N
Moscow State University, Russia.
Mikrobiologiia. 1999 Mar-Apr;68(2):211-4.
R and S dissociants of the hydrocarbon-oxidizing strain Pseudomonas aeruginosa K-2 differed but little in their growth in a minimal defined medium with glucose as the source of carbon and energy. At the same time, the number of cells of M dissociant in the late exponential phase was five orders of magnitude less than that of R and S dissociants. The growth of M dissociant was accompanied by the accumulation of formate in the culture liquid and a concurrent decrease in pH. All three dissociants contained the key enzymes of the Entner-Doudoroff pathway of glucose oxidation; however, the activities of these enzymes, especially 6-phosphogluconate dehydrogenase, were low in M dissociant. Conversely, the activity of formate dehydrogenase in cells of M dissociant was higher than in other dissociants. The activity of 6-phosphogluconate dehydrogenase, a key enzyme of the pentosephosphate pathway of glucose oxidation, was detected only in S dissociant. The peculiarities of the carbohydrate metabolism of M dissociant are probably responsible for its poor growth on glucose and determine the more pronounced anaerobic type of its metabolism.
烃氧化菌株铜绿假单胞菌K-2的R型和S型解离突变体在以葡萄糖作为碳源和能源的限定基本培养基中的生长情况差异不大。与此同时,M型解离突变体在指数生长后期的细胞数量比R型和S型解离突变体少五个数量级。M型解离突变体的生长伴随着培养液中甲酸的积累以及pH值的同时下降。所有三种解离突变体都含有葡萄糖氧化Entner-Doudoroff途径的关键酶;然而,这些酶的活性,尤其是6-磷酸葡萄糖酸脱氢酶的活性,在M型解离突变体中较低。相反,M型解离突变体细胞中甲酸脱氢酶的活性高于其他解离突变体。仅在S型解离突变体中检测到葡萄糖氧化磷酸戊糖途径的关键酶6-磷酸葡萄糖酸脱氢酶的活性。M型解离突变体碳水化合物代谢的特性可能是其在葡萄糖上生长不佳的原因,并决定了其更明显的厌氧代谢类型。