Characterization of phenol biodegradation by Comamonas testosteroni ZD4-1 and Pseudomonas aeruginosa ZD4-3.
OBJECTIVE
To investigate the characteristic and biochemical mechanism about the phenol biodegradation by bacterial strains ZD 4-1 and ZD 4-3.


METHODS
Bacterial strains ZD 4-1 and ZD 4-3 were isolated by using phenol as the sole source of carbon and energy, and identified by 16S rDNA sequence analysis. The concentrations of phenol and total organic carbon (TOC) were monitored to explore the degradation mechanism. The biodegradation intermediates were scanned at 375 nm by using a uv-vis spectrophotometer. The enzyme assays were performed to detect the activities of dioxygenases.


RESULTS
Bacterial strains ZD 4-1 and ZD 4-3 were identified as Comamonas testosteroni and Pseudomonas aeruginosa by 16S rDNA sequence analysis, respectively. The growth of the two strains was observed on a variety of aromatic hydrocarbons. The strains ZD 4-1 and ZD 4-3 metabolized phenol via ortho-pathways and meta-pathways, respectively. In addition, the results of enzyme assays showed that the biodegradation efficiency of phenol by meta-pathways was higher than that by ortho-pathways. Finally, the results of induction experiment indicated that the catechol dioxygenases, both catechol 1,2-dioxygenase (C120) and catechol 2,3-dioxygenase (C230), were all inducible.


CONCLUSIONS
The strains ZD 4-1 and ZD 4-3 metabolize phenol through ortho-pathways and meta-pathway, respectively. Furthermore, the biodegradation efficiency of phenol by meta-pathways is higher than that by ortho-pathways.
Chen
Ying-Xu
YX
Department of Environmental Engineering, Zhejiang University, Hangzhou 310029, China. yxchen@zju.edu.cn
Liu
He
H
Chen
Hua-Lin
HL
D001673:Biodegradation, Environmental; D020604:Comamonas testosteroni / Q000502:physiology*; D004202:Disinfectants / Q000378:metabolism*; D010105:Oxygenases / Q000494:pharmacology; D019800:Phenol / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D014873:Water Pollutants / Q000378:metabolism
D004202:Disinfectants; D014873:Water Pollutants; D019800:Phenol; D010105:Oxygenases