MICROBIAL DEGRADATION OF PHENOL BY A SPECIES OF ALCALIGENES ISOLATED FROM A TROPICAL SOIL

A species of Alcaligenes capable of degrading phenol at a higher concentration was isolated from a tropical soil by enrichment culture technique. The growth studies revealed that the specific growth rate (µ) decreased with increase in the concentration of phenol when phenol was used as the only carbon source in mineral medium. Even a low biomass content at 60 mM phenol concentration could bring 100 % phenol degradation. However, the subsequent increase in phenol concentration diminished both cell growth and degradation. The inhibitory concentration of phenol was 120 mM. For the biodegradation process the optimum pH was 6 and the optimum incubation period was 32 hours