Isolation and characterization of a phenol-degrading Candida tropicalis PW-51 = 페놀분해 효모 Candida tropicalis PW-51의 분리 및 분해특성

Abstract

For the biological treatment of phenolic resin wastewater containing phenol and formaldehyde, a phenol-degrading yeast was isolated from the papermill sludge, and then identified as Candida tropicalis PW-51 according to morphological, physiological and biochemical properties. The strain was able to degrade high phenol concentrations up to 2,000 mg/l within 58 hours in batch cultures. Phenol-degrading efficiency by the strain was maximum at the culture conditions of a final concentration of 9×106 cells/ml, 30°C and pH7.0. The mean degradation rate of phenol was highest at 45.5 mg/l/h in 1,000 mg/l phenol from 500 mg/l to 2,000 mg/l phenol. Because the enzyme activity of catechol 1,2-dioxygenase increased in the course of degradation of phenol, it seems that this strain degrades phenol via the ortho-cleavage of benzene ring. The isolate C. tropicalis PW-51 could be effectively used for the biological treatment of phenolic resin wastewater.