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Isolation and characterization of a phenol‐degrading Rhodococcus sp. strain AQ5NOL 2 KCTC 11961BP
Author(s) -
Arif N. M.,
Ahmad S. A.,
Syed M. A.,
Shukor M. Y.
Publication year - 2013
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.201100120
Subject(s) - phenol , chemistry , strain (injury) , biodegradation , rhodococcus , ammonium , nuclear chemistry , chromatography , organic chemistry , biology , enzyme , anatomy
In this work, we report on the isolation of a phenol‐degrading Rhodococcus sp. with a high tolerance towards phenol. The isolate was identified as Rhodococcus sp. strain AQ5NOL 2, based on 16S rDNA analysis. The strain degraded phenol using the meta pathway, a trait shared by many phenol‐degraders. In addition to phenol biodegradation, the strain was also capable of degrading diesel. Strain AQ5NOL 2 exhibited a broad optimum temperature for growth on phenol at between 20 °C and 35 °C. The best nitrogen sources were ammonium sulphate, glycine or phenylalanine, followed by proline, nitrate, leucine, and alanine (in decreasing efficiency). Strain AQ5NOL 2 showed a high tolerance and degradation capacity of phenol, for it was able to register growth in the presence of 2000 mg l −1 phenol. The growth of this strain on phenol as sole carbon and energy source were modeled using Haldane kinetics with a maximal specific growth rate ( μ max ) of 0.1102 hr −1 , a half‐saturation constant ( K s ) of 99.03 mg l −1 or 1.05 mmol l −1 , and a substrate inhibition constant ( K i ) of 354 mg l −1 or 3.76 mmol l −1 . Aside from phenol, the strain could utilize diesel, 2,4‐dinitrophenol and ρ ‐cresol as carbon sources for growth. Strain AQ5NOL 2 exhibited inhibition of phenol degradation by Zn 2+ , Cu 2+ , Cr 6+ , Ag + and Hg 2+ at 1 mg l −1 .