Fed-batch lipid production by Rhodosporidium toruloides-7191 using wood hydrolysate

The shift toward sustainable biofuels and bioproducts has increased interest in microbial production systems using renewable substrates. This study explores the use of wood hydrolysate, an abundant, cost-effective lignocellulosic substrate, as the primary carbon source for lipid and carotenoid production by Rhodosporidium toruloides-7191 under fed-batch cultivation in a 3-L bioreactor. The fed-batch strategy, chosen over batch and continuous modes, enables controlled nutrient supply, minimizes substrate inhibition, and maintains a favorable carbon-to-nitrogen ratio, thereby supporting prolonged biosynthesis and higher product yields. The process achieved a maximum lipid production of 22.33 g/L, a total lipid accumulation of 57.9% and a total carotenoid production of 4.23 mg/L. Fatty acid analysis shows a composition rich in linoleic acid (C18:2), oleic acid (C18:1), and palmitic acid (C16:0), indicating its suitability for biodiesel applications. The results emphasize R. toruloides-7191 as a promising candidate for industrial-scale applications, advancing sustainable production of biofuels and high-value bioproducts. The effectiveness of wood hydrolysate as a substrate further supports the feasibility of this approach, highlighting its potential in advancing industrial-scale processes for the production of biofuels and value-added compounds.