Optimization of Culture Conditions for Carotenoid Production by Rhodotorula mucilaginosa Isolated from Mangrove Sediments

บทคัดย่อ

Rhodotorula mucilaginosa is a carotenoid-producing yeast with high potential for biotechnological and industrial applications, particularly in the fields of pharmaceuticals, cosmetics, food additives, and animal feed, due to the antioxidant, immunomodulatory, and pigment properties of carotenoids. This yeast species is commonly found in diverse ecosystems, including both aquatic and terrestrial habitats. It is recognized for its ability to assimilate a wide range of carbon sources, making it an attractive candidate for cost-effective bioprocesses. Cultivation conditions are known to significantly influence carotenoid biosynthesis and overall productivity. This study aimed to optimize the cultivation parameters for carotenoid production by R. mucilaginosa SMY40, a strain isolated from mangrove sediments in Chonburi province, Thailand. Several factors were systematically varied, including glucose concentration, nitrogen source, initial pH, and incubation time. The optimal conditions identified were 15 g/L glucose as the carbon source, ammonium sulfate as the nitrogen source, an initial pH of 5.0, and incubation under shaking conditions at 150 rpm at room temperature for 120 hours. Under these optimized conditions, the highest biomass (dry cell weight) and carotenoid production were 4.26 ± 0.03 g/L and 41.98 ± 0.93 µg/g wet weight, respectively. Additionally, glucose consumption reached 13.36 ± 0.11 g/L. These results suggest that
R. mucilaginosa SMY40 exhibits strong potential for industrial-scale carotenoid production under economically viable conditions. The high efficiency of conversion and stability of pigment synthesis under moderate culture conditions highlight its applicability for future development in microbial pigment biotechnology.