Sporulation and synthesis of extracellular proteinases in Bacillus subtilis are more temperature-sensitive than growth.
Bacillus subtilis 115 grew in a medium with amino acids and glucose with the maximum specific growth rates mu of 1.20-1.10/h in the temperature range of 45-48 degrees C. Activity of the extracellular neutral proteinase excreted by 1.3 mg/mL dry mass during 8 h of the postexponential and stationary growth phases decreased from its maximum value of 0.23 TU/mL at 40 degrees C to 0.13 and 0.06 TU/mL at 45 and 48 degrees C, respectively. Formation of the extracellular serine proteinase decreased even more - from 0.18 TU/mL at 40 degrees C to 0.06 and 0.03 TU/mL at 45 and 48 degrees C, respectively. Sporulation, expressed as the portion of sporangia with refractile spores at the 6th h of the stationary phase decreased from 46% at 40 degrees C to 17 and 3% at 45 and 48 degrees C, respectively.
Department of Cellular and Molecular Microbiology, Academy of Sciences of the Czech Republic, Prague.
E
E
Jansová
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Z
Schwarzová
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J
Chaloupka
D001412:Bacillus subtilis / Q000502:physiology*; D002455:Cell Division; D010450:Endopeptidases / Q000096:biosynthesis*; D006358:Hot Temperature; D008666:Metalloendopeptidases / Q000096:biosynthesis; D013171:Spores, Bacterial / Q000502:physiology*; D013381:Subtilisins / Q000096:biosynthesis
D010450:Endopeptidases; D013381:Subtilisins; D008666:Metalloendopeptidases