Enhanced biodiesel and β-carotene production in Rhodotorula pacifica INDKK using sugarcane bagasse and molasses by an integrated biorefinery framework

Dependency on fossil fuels raises an economic and ecological concern that has urged to look for alternative sources of energy. Bio-refinery concept is one of the alternate frameworks for the biomass conversion into biofuel and other value-added by-products. The present work illustrates importance of an oleaginous yeast Rhodotorula pacifica INDKK in an integrated bio-refinery field by utilizing renewable sugars generated from lignocellulosic biomass. The maximum 11.8 g/L lipid titer, 210.4 mg/L beta-carotene and 7.1 g animal feed were produced by R. pacifica INDKK in bioreactor containing 5% (v/v) molasses supplemented with enzymatically hydrolyzed and alkali-pretreated sugarcane bagasse hydrolysate (35% v/v). Furthermore, xylooligosaccharides (20.6 g/L), a beneficial prebiotics were also produced from the hemicellulosic fraction separated after alkali pretreatment of bagasse. This novel concept of integrated yeast bio-refinery for concomitant production of biodiesel and multiple value-added products with minimum waste generation is proposed as a sustainable and profitable process.

Automated summary

This study highlights the importance of utilizing the bio-refinery concept to convert biomass into biofuels and value-added products. By using renewable sugars generated from lignocellulosic biomass, along with molasses and enzymatically hydrolyzed sugarcane bagasse, this study successfully produced lipids, beta-carotene, animal feed, and xylooligosaccharides.