Abstract

GROWTH KINETICS OF ALCALIGENES SP d2 DURING PHENOL BIODEGRADATION IN MINERAL SALT PHENOL MEDIUM

*Jayachandran K., Anoop M and Indu C. Nair

Abstract

Biodegradation is always considered as the safe and acceptable method for the degradation of a specific pollutant. The present study focused on the biodegradation of phenol with the bacteria Alcaligenes sp d2. The strain has been reported earlier as a potent phenol degrading bacteria and was also found to be efficient in the treatment of phenolic industrial effluent. The process of phenol degradation by Alcaligenes sp d2 was analysed in mineral salt phenol medium where phenol alone acted as the sole source of carbon and energy. The efficiency of degradation is determined by the rate of growth of the strain in the respective media. The rate of growth in terms of specific growth rate was obtained for Alcaligenes sp d2 at various concentrations of phenol from 7.5 mM to 37.5 mM. The specific growth of the bacteria was found to decrease from 0.982 to 0.484 along with the increase in the phenol concentration from 7.5 mM to 37.5 mM. The percentage of phenol degradation obtained through the organism in the same medium was also found to be decreasing from 98.2% to 72.6% upon progressively enriching the phenol concentration from 7.5 mM to 37.5 mM. As phenol itself is toxic to the bacterial species, eventhough the organism is capable of degrading phenol at lower concentrations higher concentration was found to be growth limiting as the specific growth rate was considerably reduced upon increasing phenol concentration from 7.5mM to 37.5 mM.

Keywords: Mineral salt phenol medium, kinetics, biodegradation, phenol. Alcaligenes sp d2.