Influence of metal ions concentration on phenol degradation by Rhodococcus pyridinivorans GM3

Phenol is discharged in large quantities to in the environment, and because of its persistence and high toxicity, can be a potential threat to human health; therefore, biodegradation be recognized as a best way for removing phenol from the environment. Industrial water is often polluted with metal ions, which may effect on phenol degradation. Some metal ions are useful for microorganisms but other metal ions may have toxic effects, perhaps increased metal ions in wastewater have negative impact on microorganisms. Phenol degrading bacterium was isolated from soil samples by enrichment method and has been identified as Rhodococcus pyridinivorans GM3. Rhodococcus pyridinivorans was studied to degrade phenol (1.5 and 2.0 g/L concentrations of phenol) with different concentrations of 19 different metal ions. The results showed that R. pyridinivorans GM3 was degraded phenol on concentrations 1.5 and 2.0 g/L at 150 ppm concentrations of Ba2+, As5? and Pb2+, while metal ions Ag+>Cd2+>Hg2+>Zn2+>Cu2+>Co2+have inhibited degradation of phenol (2.0 g/L concentration) was observed. The results clearly indicated that R. pyridinivorans GM3 can degrade phenol with many of metal ions and has may be employed for degradation of phenol in industrial wastewaters that are contaminated with metal ions.