Biodegradation of p-nitrophenol by Rhodococcus sp. CN6 with high cell surface hydrophobicity

Rhodococcus sp. CN6, isolated from a pesticide industry's effluent-sediment, was able to completely degrade and utilize 100 mg/L p-nitrophenol (PNP) as the sole carbon, nitrogen and energy sources for growth in the minimal salt media (MSM) within 12 h. To study the applicability of the strain for bioremediation of PNP, its degradation potential was examined in the presence of different supplemented carbon and nitrogen sources in MSM with 100 mg/L PNP. Dextrin was experienced as the best supplemented carbon source used by the strain CN6 during degrading PNP. Addition of ammonium nitrate could also increase the PNP degradation rate. Preliminary studies on the surface characters of Rhodococcus sp. CN6 were undertaken for the sake of exploring its high efficiency on the degradation of PNP. Microbial adherence to hydrocarbons (MATH) assays illuminated that the strain CN6 was of higher hydrophobicity while grown on higher concentration of PNP. The results suggested that the strain CN6 could be used as a potential and efficient PNP degrader for the bioremediation of contaminated sites.