Biodegradation of Phenol by Newly Isolated Phenol-degrading Bacterium Ralstonia sp. Strain PH-S۱

A newly phenol-degrading bacterium, identified as Ralstonia sp. strain PH-S۱, was isolated from oil-contaminated soil in Khark Island. It was isolated by a multistep enrichment and screening technique on mineral medium (MM) containing ۱۰۰ mg.l-۱ of phenol as the sole source of carbon. The bacterium was able to degrade up to ۱۱۰۰ mg.l-۱ of phenol but the cell growth decreased with higher concentrations of phenol. The PH-S۱ strain grew well in the pH range of ۴ to ۹ and in the temperature range of ۳۰ to ۴۰ °C. Different concentrations of NaCl ranging from ۱۰ to ۲۰% on the growth of bacteria was studied and it was found that this strain was able to grow well in ۱۰% 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.

Keywords:

Isolation , Ralstonia , Phenolic Compounds , Industrial Wastewaters