UTILIZATION OF PHOSPHATES IN THE POSTGERMINATIVE DEVELOPMENT OF SPORES OF BACILLUS MEGATERIUM

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Abstract
Spores germinate in glucose in the absence of phosphate, but no development of these germinated spores into vegetative cells occurs. The addition of orthophosphate, at a concentration of at least 0.5 to 1.0 m[image] supports postgerminative development of over 90% of the germinated spores in a suspension containing 4.2 x 108 spores per ml. Many other inorganic and organic phosphate compounds also permit this development. Some of these compounds (e.g., sodium trimetaphosphate, sodium tripolyphosphate, glucose-1-phosphate, and glucose-6-phosphate) are more readily utilized in the presence of metal activators such as Mn++. Intact germinated spores hydrolyze pyrophosphate, but orthophosphate can be demonstrated only under conditions which inhibit postgerminative development (inhibitory chemicals, low pH). The presence of more than a single pyrophosphatase is suggested by metal activation and pH data. Hydrolysis of many phosphorylated compounds, which support postgerminative development was not demonstrated. Spores germinate in a broad pH range, with an optimum from 5.9 to 7.3, but normal postgerminative development does not occur unless the pH is oyer 6.4, and optimal development is between 7.5 and 8.0. Germination occurs in an oxygen-free atmosphere, but postgerminative development occurs only under aerobic conditions.