[P003] Poster

12:10 PM - 1:00 PM JST(3:10 AM - 4:00 AM UTC)

[P02-291] Effects of Culture Temperature and Light on Carotenoid Production in Oleaginous Yeasts

○Ayako Suzuki¹, Sakura Toyoshima¹, Takanori Inoue¹ (1. Oita Universitiy (Japan))

Keywords:

carotenoids,oleaginous yeast,Rhodotorula toruloides,culture condition optimization,temperature stress

Carotenoids are naturally occurring pigments widely distributed in plants and microorganisms and are known to exhibit diverse physiological functions, including antioxidant activity, photoprotection, and cellular protection. Due to their structural diversity, carotenoids display a wide range of physicochemical properties and biological activities, leading to their application in various industrial fields. In recent years, increasing demand for naturally derived compounds has highlighted the need for stable and efficient carotenoid production methods.This study focused on carotenoid production in oleaginous yeasts and aimed to clarify the effects of culture temperature and light irradiation conditions on carotenoid yield and composition. Differences in strain-specific responses to cultivation conditions were examined to identify conditions for high-efficiency carotenoid production and to obtain fundamental insights into production control.Two strains of Rhodotorula toruloides (SAK009 and SAK010), previously reported to possess carotenoid-producing capabilities, were used. Carotenoids were extracted using ethanol. To assess temperature effects, each strain was cultivated at 30 °C and 5 °C for one month. Light irradiation experiments were conducted using a 3 W white LED under five conditions: no treatment, light-shielded, and red, green, or blue light. After cultivation, absorption spectra of ethanol extracts were measured using a spectrophotometer.SAK009 exhibited the highest carotenoid production at 30 °C, whereas production decreased at 5 °C. In contrast, SAK010 showed enhanced carotenoid production at 5 °C, while little production was observed at 30 C. Under light irradiation, SAK009 showed increased production under all tested conditions, whereas SAK010 showed decreased production only under dark conditions. Spectral analysis indicated that SAK009 primarily produced beta-carotene, while SAK010 exhibited peaks suggestive of multiple carotenoids. Temperature-dependent differences in carotenoid composition were also observed.These results demonstrate that carotenoid production in oleaginous yeasts is strongly influenced by culture temperature and light conditions in a strain-dependent manner. In particular, culture temperature affected both carotenoid yield and composition. These findings indicate that optimization of cultivation conditions enables control of carotenoid production and provides a fundamental basis for efficient biotechnological production using oleaginous yeasts.