Enzymatic degradation of aliphatic nitriles by Rhodococcus rhodochrous BX2, a versatile nitrile-degrading bacterium.
Nitriles are common environmental pollutants, and their removal has attracted increasing attention. Microbial degradation is considered to be the most acceptable method for removal. In this work, we investigated the biodegradation of three aliphatic nitriles (acetonitrile, acrylonitrile and crotononitrile) by Rhodococcus rhodochrous BX2 and the expression of their corresponding metabolic enzymes. This organism can utilize all three aliphatic nitriles as sole carbon and nitrogen sources, resulting in the complete degradation of these compounds. The degradation kinetics were described using a first-order model. The degradation efficiency was ranked according to t1/2 as follows: acetonitrile>trans-crotononitrile>acrylonitrile>cis-crotononitrile. Only ammonia accumulated following the three nitriles degradation, while amides and carboxylic acids were transient and disappeared by the end of the assay. mRNA expression and enzyme activity indicated that the tested aliphatic nitriles were degraded via both the inducible NHase/amidase and the constitutive nitrilase pathways, with the former most likely preferred.
College of Resource and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China; College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 16339, Heilongjiang, PR China.
Shumei
S
Fang
College of Resource and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
Xuejiao
X
An
College of Resource and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
Hongyuan
H
Liu
College of Resource and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
Yi
Y
Cheng
College of Resource and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
Ning
N
Hou
College of Resource and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
Lu
L
Feng
College of Resource and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
Xinning
X
Huang
College of Resource and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China. Electronic address: chunyanli@neau.edu.cn.
Chunyan
C
Li
D000581:Amidohydrolases / Q000378:metabolism*; D000619:Aminohydrolases / Q000378:metabolism*; D001673:Biodegradation, Environmental; D006836:Hydro-Lyases / Q000378:metabolism*; D009570:Nitriles / Q000378:metabolism*; D012240:Rhodococcus / Q000145:classification / Q000378:metabolism*; D013045:Species Specificity; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000379:methods
D009570:Nitriles; D014874:Water Pollutants, Chemical; D000581:Amidohydrolases; C019665:amidase; D000619:Aminohydrolases; C021867:nitrilase; D006836:Hydro-Lyases; C048831:nitrile hydratase
Aliphatic nitrile degradation; Amidase; Nitrilase; Nitrile hydratase; Rhodococcus rhodochrous BX2