Optimization of SSF parameters for natural red pigment production from Penicillium purpurogenum using cassava waste by central composite design

Abstract

Pencillium purpurogenum 8904.12, a red pigment producer, was isolated from soil screened and selected based on the pigment production. The pigment production by P.purpurogenum was optimizedby using factorial design and Response Surface Methodology (RSM) in SSF. Cassava waste is a low cost and nutrient rich substrate used in this study as a substrate. RSM based central composite design was employed to obtain best combination of substrate concentration, inoculum volume, incubation time, initial moisture and initial pH. By the point prediction tool of Design-Expert 8.0, the optimum values of the factors for maximum red pigment production were determined. Under the optimized conditions (substrate concentration 10 g, inoculum volume 5 ml, 15 days incubation time, 50 % initial moisture and initial pH of 6), the red pigment yield was 28.33 colour value units / g of dry fermented substrate which agreed closely with the predicted yield. The model showed that the value of R2 (0.9936) was high and pvalue of interaction of variance was <0.0001. Hence the model can be said to be of highly significant. A significant Increase in red pigment production was achieved using RSM. Thus, utilization of cassava waste for red pigment production in this study could provide the most effective use of cassava resource, and lead to technology of development for its further utilization and value addition.