Degradation of the metal-cyano complex tetracyanonickelate (II) by Fusarium oxysporum N-10.
A fungus with the ability to utilize a metalcyano compound, tetracyanonickelate (II) ¿K2[Ni (CN)4]; TCN¿, as its sole source of nitrogen was isolated from soil and identified as Fusarium oxysporum N-10. Both intact mycelia and cell-free extract of the strain catalyzed hydrolysis of TCN to formate and ammonia and produced formamide as an intermediate, thereby indicating that a hydratase and an amidase sequentially participated in the degradation of TCN. The enzyme catalyzing the hydration of TCN was purified approximately ten-fold from the cell-free extract of strain N-10 with a yield of 29%. The molecular mass of the active enzyme was estimated to be 160 kDa. The enzyme appears to exist as a homotetramer, each subunit having a molecular mass of 40 kDa. The enzyme also catalyzed the hydration of KCN, with a cyanide-hydrating activity 2 x 10(4) times greater than for TCN. The kinetic parameters for TCN and KCN indicated that hydratase isolated from F. oxysporum was a cyanide hydratase able to utilize a broad range of cyano compounds and nitriles as substrates.
Yanase
H
H
Department of Biotechnology, Tottori University, Japan. yanase@bio.tottori-u.ac.jp
Sakamoto
A
A
Okamoto
K
K
Kita
K
K
Sato
Y
Y
D000595:Amino Acid Sequence; D001673:Biodegradation, Environmental; D003470:Culture Media; D003486:Cyanides / Q000378:metabolism*; D005670:Fusarium / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism*; D006836:Hydro-Lyases / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D009532:Nickel / Q000378:metabolism*; D012988:Soil Microbiology
D003470:Culture Media; D003486:Cyanides; C047503:tetracyanonickelate; D009532:Nickel; D006836:Hydro-Lyases; C076848:cyanide hydratase