Biodegradation of 4-nitrophenol by a Rhodococcus species and a preliminary insight into its toxicoproteome based on mass spectrometry analysis
Journal of environmental biology
Aim : Methodology : Results : Interpretation : The objective of this study was to understand the possible fate of 4-NP through the molecular mechanism and to identify potential enzymes involved in 4-NP biodegradation by Rhodococcus sp. strain BUPNP1. Biodegradation of 4-NP was detected spectrophotometrically at 400 nm and also confirmed by TLC and HPLC. Comparative study of proteomes was performed by 2-D gel electrophoresis followed by peptide mass fingerprinting and bioinformatic analysis to
... matic analysis to identify and/ or predict the possible functions of over-expressed proteins in 4-NP treated cells of BUNP1. Utilization of 4nitrophenol and its hydrolysis intermediate 4-nitrocatechol (4-NC) and 1,2,4-Benzenetriol as sole carbon source indicated the presence of genomic information encoding the enzyme necessary for the operation of 4-nitrophenol degradation pathway in the strain BUPNP1. It could transform 4-NP into 4-NC by monooxygenase whose major activity was detected during initial stage of degradation. The 4-NC further depleted in the medium to release nitrite ions. In order to investigate the molecular changes occurring d u r i n g d e g r a d a t i o n , a comparative study of proteome profiles was carried out where; 4nitrophenol treated cells were compared against cells grown on glucose as control. The comparative study indicated expression of several protein spots under 4-nitrophenol treated condition. This study showed the potential of BUPNP1 strain belonging to genus Rhodococcus towards induced expression of some unique proteins which might have possible role in 4-NP biodegradation process.