Novel cyanide-hydrolyzing enzyme from Alcaligenes xylosoxidans subsp. denitrificans

Journal Article · Sat Jun 01 04:00:00 EDT 1991 · Applied and Environmental Microbiology; (United States)

OSTI ID:5203899

Ingvorsen, K; Hojer-Pederson, B; Godtfredsen, S E ^[1]

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1. Novo Nordisk A/S, Bagsvaerd (Denmark)

A cyanide-metabolizing bacterium, strain DF3, isolated from soil was identified as Alcaligenes xylosoxidans subsp. denitrificans. Whole cells and cell extracts of strain DF3 catalyzed hydrolysis of cyanide to formate and ammonia (HCN + 2H{sub 2}O {r arrow} HCOOH + NH{sub 3}) without forming formamide as a free intermediate. The cyanide-hydrolyzing activity was inducibly produced in cells during growth in cyanide-containing media. Cyanate (OCN{sup {minus}}) and a wide range of aliphatic and aromatic nitriles were not hydrolyzed by intact cells of A. xylosoxidans subsp. denitrificans DF3. Strain DF3 hydrolyzed cyanide with great efficacy. Thus, by using resting induced cells at a concentration of 11.3 mg (dry weight) per ml, the cyanide concentration could be reduced from 0.97 M (approximately 25,220 ppm) to less than 77 nM (approximately 0.002 ppm) in 55 h. Enzyme purification established that cyanide hydrolysis by A. xylosoxidans subsp. denitrificans DF3 was due to a single intracellular enzyme. The molecular mass of the active enzyme (purity, {gt}97% as determined by amino acid sequencing) was estimated to be {gt}300,000 Da. The cyanide-hydrolyzing enzyme of A. xylosoxidans subsp. denitrificans DF3 was tentatively named cyanidase to distinguish it from known nitrilases (EC 3.5.5.1) which act on organic nitriles.

• OSTI ID: 5203899
• Journal Information: Applied and Environmental Microbiology; (United States), Journal Name: Applied and Environmental Microbiology; (United States) Vol. 57:6; ISSN 0099-2240; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540210* -- Environment
Terrestrial-- Basic Studies-- (1990-)
AMINO ACID SEQUENCE
AMMONIA
BACTERIA
BIODEGRADATION
CARBOXYLIC ACID SALTS
CHEMICAL REACTIONS
CYANIDES
DECOMPOSITION
ENZYMATIC HYDROLYSIS
ENZYME ACTIVITY
ENZYMES
FORMATES
HYDRIDES
HYDROGEN COMPOUNDS
HYDROLASES
HYDROLYSIS
LYSIS
METABOLISM
MICROORGANISMS
MOLECULAR STRUCTURE
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
PURIFICATION
SOLVOLYSIS