Degradation of Phenol, an Innovative Biological Approach

Abstract

A bacterial strain capable of utilizing phenol as a sole carbon source was isolated from the soil samples, collected at a vicinity of industrial wastewater treatment plant of phenol manufacturing unit. Based on the biochemical tests and 16S rRNA sequencing results the organism was identified as Serratia marcescens. The organism is capable of degrading the highly toxic phenolic compound to an optimum concentration of 2500 mgL^-1 in 120 h at approx. a neutral pH of 8. The organism was also efficient with wide pH and temperature tolerance with an extremely stipulated lag phase in the case of higher influent concentrations. Amid two different models incorporated to justify the growth kinetics of the organism the Haldane’s model fits (R²=0.930) very satisfactorily with kinetic constants in the range of m_max = 0.05 - 0.095 h^-1; K_s = 8.49 - 16.1 mgL^-1; Kj - 1154.75 - 1700.68 mgL^-1. Despite limitations in terms of inhibition of microbial growth subjected to an extremely elevated concentration of phenol the study claims the feasibility of Serratia marcescens to an utmost concentration of 2500 mg/L and suggests the method as best possible alternative to the existing chemical treatment procedures.    

Keywords: Biodegradation; Phenol; Serratia marcescens; Kinetic modeling, Phenolic compounds