Coconut oil cake––a potential raw material for the production of α-amylase

Abstract

Solid-state fermentation (SSF) was carried out using coconut oil cake (COC) as substrate for the production of α-amylase using a fungal culture of Aspergillus oryzae. Raw COC supported the growth of the culture, resulting in the production of 1372 U/gds α-amylase in 24 h. Process optimization using a single parameter mode showed enhanced enzyme titre, which was maximum (1827 U/gds) when SSF was carried out at 30 °C for 72 h using a substrate with 68% initial moisture. Supplementation with glucose and starch further enhanced enzyme titre, which was maximum (1911 U/gds) with 0.5% starch. However, maltose inhibited the enzyme production. Studies on the effect of addition of external organic and inorganic nitrogenous compounds further showed a positive impact on enzyme synthesis by the culture. Increase of 1.7-fold in the enzyme activity (3388 U/gds) was obtained when peptone at 1% concentration was added to the fermentation medium. The enzyme production was growth-related, the activity being the maximum when the fungal biomass was at its peak at 72 h.