Biodegradation of Phenol by Newly Isolated Phenol-degrading Bacterium Ralstonia sp. Strain PH-S1

Abstract

A newly phenol-degrading bacterium, identified as Ralstonia sp. strain PH-S1, was isolated from oil-contaminated soil in Khark Island. It was isolated by a multistep enrichment and screening technique on mineral medium (MM) containing 100 mg.l-1 of phenol as the sole source of carbon. The bacterium was able to degrade up to 1100 mg.l-1 of phenol but the cell growth decreased with higher concentrations of phenol. The PH-S1 strain grew well in the pH range of 4 to 9 and in the temperature range of 30 to 40 °C. Different concentrations of NaCl ranging from 10 to 20% on the growth of bacteria was studied and it was found that this strain was able to grow well in 10% NaCl; but, higher concentrations of NaCl decreased the growth of the strain. The laboratory scale results indicated the potential application of the strain in the treatment of low saline industrial wastewaters. However, further investigations are required to confirm the ability of the strain.