Abstract

DEGRADATION OF PHENOL USING A PHB PRODUCING BACILLUS SUBTILIS SP3

Indu Chandrasekharan Nair* and Sukanya Prakash

Abstract

The bacterial isolate from soil grown in the designed synthetic medium with phenol as the sole carbon and energy source could degrade phenol completely. The isolate showed fast acclimatization in the minimal medium. Polyhydroxy butyrate (PHB), an alternative to synthetic plastic was also extracted from the same bacterial isolate. The PHB granules from the newly screened strain designated as sp3 were visualized by atomic force microscopy. 16S rRNA analysis of the bacterial isolate established the identity of the strain as Bacillus subtilis sp. The effect of pH and incubation time under phenol stress were optimized for maximum growth. It was observed that the optimum pH was 7, incubation time was 24 hours and phenol concentration was 12 mM. The degradation was analyzed by Fourier Transform Infra-Red spectroscopy. This strain could also be successfully used for the laboratory scale treatment of paper mill effluent containing phenolic components. The wastewater showed a considerable COD reduction of 64% after 24 hours of treatment.

Keywords: Phenol degradation, Bacillus subtilis sp3, Poly Hydroxy Butyrate, Fourier Transform Infrared Spectroscopy, Chemical Oxygen Demand.