ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract Two mutant strains of Bacillus licheniformis insensitive to catabolite repression were selected by classical mutagenesis in connection with the development of a fed-batch procedure for protease production. B. licheniformis 4a produced up to 20 U (Anson-Units) subtilisin Carlsberg/ml in fed-batch experiments in the presence of up to 1.5 m glycerol, but was inhibited by excess ammonium. Formation of spores, excretion of α-amylase and the biosynthesis of citrate synthase and isocitrate dehydrogenase were likewise not repressed by glycerol. The strain was characterized by unusually low activity of the α-oxoglutarate dehydrogenase complex and increased biosynthesis of polyglutamic acid in the presence and excretion of α-oxoglutarate in the absence of ammonium, respectively. The results are discussed in view of a possible connection between the defect in the α-oxoglutarate dehydrogenase complex and insensitivity to catabolite repression. The second strain B. licheniformis 114 was able to synthesize 11.5 U protease/ml independently of the glycerol and ammonium concentration in the medium.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00173316
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