Sugarcane bagasse hydrolysate as a potential feedstock for red pigment production by Monascus ruber

Abstract

Sugarcane bagasse (SCB) hydrolysate could be an interesting source for red pigment production by Monascus ruber Tieghem IOC 2225. The influence of different wavelength of light-emitting diode (LED) at 250 μmol.m^-2.s^-1 of photon flux density on red pigment production by M. ruber in glucose-based medium was evaluated. Then, SCB hydrolysate was used as carbon source under the previously selected light incidence conditions. In glucose-based medium, the highest pigment production was achieved in fermentation assisted with orange LED light (8.28 UA_490nm), white light (8.26 UA_490nm) and under dark condition (7.45 UA_490nm). By using SCB hydrolysate-based medium, the highest red pigment production (18.71 AU_490nm) was achieved under dark condition and the glucose and cellobiose present in the hydrolysate were metabolized. SCB enzymatic hydrolysate was demonstrated to be a promising carbon source for high thermal stability red pigment production (activation energy of 10.5 kcal.mol^-1), turning an interesting alternative for implementation in biorefineries.

Keywords: Enzymatic hydrolysate; Light-emitting diode; Monascus ruber; Red pigment; Sugarcane bagasse; Thermal stability.