OPTIMIZATION STUDIES ON BISPHENOL A DEGRADING ENZYME AND BIODEGRADATION PROCESS

Abstract

Three actinobacterial isolates (Actinomyces naeslundii, Actinomyces bovis and Actinomyces israelii) were screened for their ability to utilize bisphenol A (BPA) as sole carbon source. Optimization studies were carried out on the actinobacterial isolates to determine the optimum pH, best media nitrogen source and consortia for laccase production and BPA degradation. Optimum pH values for growth, lacasse production and BPA degradation were 6.0, 7.0 and 8.0 for A. naeslundii, A. bovis and A. israelii respectively. Yeast extract supported maximal growth, laccase production, and BPA degradation by the actinobacterial under study. Enzyme yield and BPA degradation by A. naeslundii was 7.8 U/Land 76 % while A. bovis and A. israelii achieved laccase yield and BPA degradation of 6.9 U/L, 79 % and 6.2 U/L, 74 % respestively. Also, a three-member actinobacterial consortium gave higher production of laccase (15.9 U/L) and more effective BPA degradation (91.3 %) than either two-member consortium or single organism. This study shows that optimized process parameter enhance biodegradation of BPA through improved enzyme production.