Secretion of a trypsin-like thiol protease by a new keratinolytic strain of Bacillus licheniformis.
When cultured in feather-containing broth with a growth optimum of pH 7.0 and 47 degrees C, a Bacillus licheniformis strain exhibited a high chicken feather-degrading activity. A trypsin-like protease was isolated from its ferment broth and was partially characterized. The enzyme was constitutively secreted and was highly active towards N-benzoyl-Phe-Val-Arg-p-nitroanilide as chromogenic substrate. Its pH optimum was 8.5 and it exhibited the highest activity at 52 degrees C. Fractionation on Sephadex G-100 column revealed that its molecular mass was about 42 kDa. The enzyme, which is new for the genus Bacillus, is a thiol protease, as tosyl-L-phenylalanine chloromethyl ketone, tosyl-L-lysine chloromethyl ketone, phenylmethylsulfonyl fluoride and ethylenediamine tetraacetate did not inhibit it, while HgCl2 and para-chloromercuribenzoate lowered its activity.
Rozs
M
M
Department of Microbiology, University of Szeged, P.O. Box 533, H-6701, Szeged, Hungary. rozsm@bio.u-szeged.hu
Manczinger
L
L
Vágvölgyi
C
C
Kevei
F
F
D000818:Animals; D001407:Bacillus / Q000201:enzymology* / Q000254:growth & development; D002645:Chickens; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D005241:Feathers; D006863:Hydrogen-Ion Concentration; D007633:Keratins / Q000378:metabolism*; D008970:Molecular Weight; D009842:Oligopeptides / Q000378:metabolism; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D013696:Temperature; D014357:Trypsin; D020245:p-Chloromercuribenzoic Acid / Q000494:pharmacology
D009842:Oligopeptides; D013439:Sulfhydryl Reagents; C006164:S 2160; D020245:p-Chloromercuribenzoic Acid; D007633:Keratins; D014357:Trypsin; D003546:Cysteine Endopeptidases