RESPONSE SURFACE METHODOLOGY FOR THE OPTIMIZED PRODUCTION OF AN ALKALOPHILIC LACCASE FROM GAMMA-PROTEOBACTERIUM JB

Gamma-proteobacterium JB, an alkali-tolerant soil isolate, produced laccase (8X103 nkat/L) in M162 medium. The optimization of process conditions (pH, incubation time, agitation, and CuSO4 concentration) for laccase production during submerged fermentation was carried out using response surface methodology (RSM) based on a central composite design (CCD). Maximum laccase production achieved was 7.4 X 104 nkat/L at pH 8.0, 210 rpm, 100 µM of CuSO4 after 60 h of incubation. This design of experiment methodology increased laccase production by 9.3 fold over the control. Experimental findings were in close agreement with the model predictions.