Synthesis of exocellular proteins during the exponential and stationary phase of growth of Bacillus megaterium

Abstract

Synthesis of exocellular metalloprotease and cellular and exocellular proteins in the sporogenic strain Bacillus megaterium J-27 and asporogenic strain KM 1 was investigated. Both organisms excrete the enzyme into the medium during growth and during the stationary phase. In the asporogenic strain the excretion decreases at the end of the exponential phase. In the sporogenic strain it continues during the transition to the stationary phase at the original rate and proteolytic activity in the medium increases two to three times during 2 h after the end of the exponential phase. Both organisms synthesize relatively more exocellular proteins during the exponential phase than during the stationary phase. The proportion of exocellular protein synthesized during the exponential phase does not exceed 3 % of total proteins, during the stationary phase this proportion usually decreases to less than 1 %.