Saccharified sugarcane bagasse as a substrate for astaxanthin production by Xanthophyllomyces dendrorhous

Astaxanthin is a carotenoid of great industrial importance due to its antioxidant properties and applications in the pharmaceutical and food industries. The primary production is carried out synthetically due to the high costs of the natural output. Xanthophyllomyces dendrorhous is a yeast that grows on several substrates and produces astaxanthin. Saccharified sugarcane bagasse (SCBS) was evaluated as a low-cost substrate to reduce costs in producing natural astaxanthin. In optimizing the enzymatic saccharification process of sugarcane bagasse (enzyme units, temperature, pH, and reaction time), 68.1%+/- 2.6 holocellulose conversion was obtained with 2000 UEG/g SCBS, at 55 degrees C, pH 4.8 for 12 h. X. dendrorhous wild (WT) and R4 strains were cultured on glucose, xylose, and SCBS to determine the effect of carbon sources on growth and production of astaxanthin. R4 strain had higher growth in glucose compared to xylose. However, in SCBS cultures containing the mixture of these sugars, growth increased 4.73-fold to that of glucose. SCBS also favored astaxanthin production, having the highest output compared to pure sugars, with titers of 2.73 and 3.24 mg/L for the WT and R4 strains, respectively. The results confirm that SCBS is a potential substrate for enhancing astaxanthin production by X. dendrorhous, which could improve the biotechnological production of carotenoids.