Biodegradation of phenol by Stenotrophomonas sp. and Staphylococcus sp. isolated from contaminated sites

Phenol as environmental pollutant is detrimental to living organisms and needed to be eliminated for environmental safety. Among the various practiced approaches for its removal, bacterial utilization gets attraction due to its eco-friendly and cost effective nature. For this purpose, bacterial strains were isolated from bioremediation site and industrial waste through enrichment in phenol (250 mg L-1) for 3 days at 28°C. After enrichment, morphologically distinct colonies were purified on phenol (200 mg L-1) agar plates and the strains were identified through 16S rRNA gene sequence. Total of eight strains were identified, among them two strains, NCCP-310 and NCCP-405 had the best potential of phenol degradation which were identified as the members of the genera Stenotrophomonas and Staphylococcus. NCCP-310 and NCCP- 405 showed 98.85 and 98.9% sequence identity with Stenotrophomonas maltophilia and Staphylococcus equorum subsp. equorum, respectively. Both strains have ability to tolerate 1000 mg L-1 phenol. The isolated strains degraded 750 mg L-1 of phenol at pH 7 and 28+2°C. NCCP-310 and NCCP-405 showed degradation of such amount in 65 and 85 h with the average rate of 15.65 and 11.64 mg L-1 h-1. Our work suggests that these strains are efficient in phenol removal and could be used for bioremediation.