Optimization of the fermentation conditions for chitin deacetylase (CDA) production by Penicillium oxalicum SAEM-51 was undertaken in the present study using central composite design (CCD) under submerged condition. CDA is widely employed for bio-catalytic conversion of chitin to chitosan. Chitosan is a biopolymer with immense commercial potential in diverse industrial sectors, viz. pharmaceutics, food, agriculture, water treatment, etc. CDA production was significantly affected by all the variables studied, viz. pH, temperature, inoculum age and size. The optimal conditions that stimulating maximal CDA production were found to be: pH, 7.9; temperature, 28 °C; inoculum age, 90 h, and 11 % inoculum size. Under these optimized conditions, the actual maximal CDA production was 623.57 ± 8.2 Ul-1, which was in good agreement with the values predicted by the quadratic model (648.24 Ul-1), confirming the validity of the model. Optimization of fermentation conditions through CCD had resulted into 1.4-fold enhancement in CDA productivity (Qp = 4.3264 Ul-1 h-1). Results of these experiments indicated that response surface methodology was proved to be a promising method for optimization of CDA production.
Keywords: Central composite design; Chitin deacetylase; Chitosan; Fermentation conditions; Penicillium oxalicum.