Biodegradation of Phenol by Isolated Bacterial Strain Psuedomonas spp. from Gola river water of Nainital

Abstract

The biodegradation process for phenol was investigated using an isolated single bacterial culture of Psueudomonas spp. by serial dilution of river water and soil samples procured from the river bank of river Gola, Nainital. The Psuedomonas spp. was able to reduced 80-85 % pollution load within 48 hrs under aerobic condition in terms of Chemical Oxygen Demand (COD) in River Water containing Phenol (RWP). These strains were examined for their ability to degrade phenol by plate assay method by varying phenol concentration (1 mM-10 mM) using Phenol-MSM media. The mode of ring cleavage was being carried-out via ortho-cleavage pathway i.e., phenol hydroxylase was responsible for the high tolerance to high phenol concentration as correlated by Psueudomonas spp. showing, the maximum activity of phenol hydroxylase. The influence of four process parameters studied temperature (20-60o C), pH (4-9), substrate (1-10 mM) and agitation speed (30-150 rpm) influenced the rate of biodegradation extent. Optimum pH for phenol biodegradation was observed at 7.5, which was almost stable at increasing pH range up to 8.0. The effect of temperature on the activity of enzyme was significant and maximum activity lies within the range of 35-45o C at static condition at an optimum substrate concentration of (6-8 mM). The enzyme activity remained fairly good at 55o C i.e., enzyme is stable at high temperature.