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Proteases of psychrotrophic bacteria isolated from glaciers
Author(s) -
Margesin Rosa,
Palma Norbert,
Knauseder Franz,
Schinner Franz
Publication year - 1991
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.3620310515
Subject(s) - proteases , flavobacterium , psychrotrophic bacteria , microbiology and biotechnology , protease , bacteria , pseudomonas , biology , pseudomonadaceae , strain (injury) , enzyme , chemistry , biochemistry , genetics , anatomy
25 psychrotrophic protease‐forming bacteria isolated from glaciers were identified as follows: Pseudomonas spp. (18 strains), Flavobacterium spp. (3 strains), Xanthomonas maltophilia (2 strains), Aeromonas hydrophila (1 strain) and Bacillus sp. (1 strain). Characteristics of proteolytic activity in cell‐free culture supernatants were studied. Proteases produced by 40% of the bacteria showed a maximum azocaseinolytic activity around 40°C and pH 7. Enzymes were rapidly inactivated after heating at 50°C. pI‐values of proteases ranged from > 9.5 to 7.0. Sensitivity to EDTA indicates that most proteases are metalloproteases. Proteases of psychrotrophs could be differentiated from proteases of mesophiles by a lower temperature optimum, a lower activation energy and a higher sensitivity against heat treatment.