Cyanide hydrolysis in a cyanide-degrading bacterium, Pseudomonas stutzeri AK61, by cyanidase.
The cyanide-degrading bacterial strain AK61 was isolated from waste water at a metal-plating plant. The isolated strain was characterized by Gram-staining, quinone analysis, fatty acid profile and the API 20NE identification system, and identified as Pseudomonas stutzeri. Whole cells were able to degrade cyanide rapidly in a 1 mM solution containing no organic substances, and produced ammonia as a product. The induction of the cyanide-degrading activity of P. stutzeri AK61 did not depend on the presence of cyanide in the culture medium during growth. The cyanide-degrading enzyme was purified approximately 49-fold from a cell extract of P. stutzeri AK61. The enzyme had a K(m) of 1.7 mM for cyanide and a specific activity of 54.6 mumol ammonia produced min-1. The activity of the enzyme was optimal at 30 degrees C and pH 7.5. The results of SDS-PAGE, gel-filtration chromatography and NH2-terminal amino acid sequence analysis of the enzyme indicated that the functional enzyme was an aggregated protein consisting of a 38 kDa polypeptide. Like cyanidase (cyanide dihydratase), it was shown that the enzyme catalysed the hydrolysis of cyanide to ammonia and formate.
Watanabe
Atsushi
A
Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153, Japan.
Yano
Kazuyoshi
K
Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153, Japan.
Ikebukuro
Kazunori
K
Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153, Japan.
Karube
Isao
I
Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153, Japan.
D000595:Amino Acid Sequence; D003486:Cyanides / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005227:Fatty Acids / Q000032:analysis; D006867:Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D006868:Hydrolysis; D008969:Molecular Sequence Data; D011549:Pseudomonas / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D011809:Quinones / Q000032:analysis; D017386:Sequence Homology, Amino Acid; D014871:Water Microbiology
D003486:Cyanides; D005227:Fatty Acids; D011809:Quinones; D006867:Hydrolases