Mineralization of p-nitrophenol by a new isolate Arthrobacter sp. Y1

Abstract

Arthrobacter sp. Y1, capable of metabolizing p-nitrophenol (PNP) as the sole carbon, nitrogen and energy source was isolated from activated sludge. The bacterium could tolerate concentrations of PNP up to 600 mg L^{− 1}, and degradation of PNP was achieved within 120 h of incubation. PNP and its metabolites were analyzed by high performance liquid chromatography (HPLC). The metabolite formed indicated that the organism followed the 4-nitrocathechol (4-NC) pathway for metabolism of this compound. The relevant degrading-enzyme was extracellular. Addition of other carbon source (glucose 0∼ 30 g L^{− 1}) led to accelerated degradation. If the glucose concentration exceeded 30 g L^{− 1}, however, degradation was repressed. Spectrophotometry assay of the nitrite and genotoxic study showed that strain Y1 could detoxify PNP. Therefore, the present study may provide a basis for the development of the bioremediation strategies to remedy the pollutants in the environment.

Keywords:

• Arthrobacter sp
• biodegradation
• p-nitrophenol
• mineralization
• supernatant

Acknowledgments

This work was supported by the Hi-tech Research and Development Program of China (No.2008AA10Z402 and No.2006AA10Z401). We are indebted to Yongxin Nie (College of Life Sciences, Shandong Agricultural University) for providing facilities and helping with HPLC.