Isolation and characterization of a feather-degrading enzyme from Bacillus pseudofirmus FA30-01.
We isolated the feather-degrading Bacillus pseudofirmus FA30-01 from the soil sample of poultry farm. The isolate completely degraded feather pieces after liquid culture at 30 degrees C (pH 10.5) for 3 days. Strain FA30-01 is a Gram-positive, spore-forming, rod-shaped bacterium and was identified with B. pseudofirmus based on 16S rDNA analysis. The keratinase enzyme produced by strain FA30-01 was refined using ammonium sulfate precipitation, negative-ion DEAE Toyopearl exchange chromatography, and hydroxyapatite chromatography. The refinement level was 14.5-fold. The molecular weight of this enzyme was 27.5 kDa and it had an isoelectric point of 5.9. The enzyme exhibited activity at pH 5.1-11.5 and 30-80 degrees C with azokeratin as a substrate, although the optimum pH and temperature for keratinase activity were pH 8.8-10.3 and 60 degrees C, respectively. This enzyme is one of the serine-type proteases. Subtilisin ALP I and this enzyme had 90% homology in the N-terminal amino acid sequence. Since this enzyme differed from ALP I in molecular weight, heat resistance and isoelectric point, they are suggested to be different enzymes.
Graduate School of Life Sciences, Toyo University, 1-1-1 Izumino, Oura-gun, Gunma 374-0193, Japan. dx0300012@toyonet.toyo.ac.jp
Mio
M
Kojima
Mieko
M
Kanai
Mari
M
Tominaga
Shunichi
S
Kitazume
Akira
A
Inoue
Koki
K
Horikoshi
D000595:Amino Acid Sequence; D000818:Animals; D001407:Bacillus / Q000145:classification* / Q000187:drug effects / Q000201:enzymology*; D003470:Culture Media; D005241:Feathers / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013696:Temperature
D003470:Culture Media; D011480:Protease Inhibitors; D010447:Peptide Hydrolases; C035855:keratinase