Evaluation of Light-Emitting Diodes Applied to Rhodotorula mucilaginosa to Produce Carotenoids and Lipids

This study was aimed at evaluating the effects of light-emitting diode (LED) (blue, green, red, and white) on carotenoid and lipid production by Rhodotorula mucilaginosa CCT 7688. Results showed that LED at 50 µmol m⁻² s⁻¹ enhanced carotenoid production in all colors under study, by comparison with the control (1794.21 µg L⁻¹). However, both green (3473.00 µg L⁻¹) and red (3497.76 µg L⁻¹) stood out in the production since there was increase of 93.5 and 94.9%, respectively. β-Carotene and astaxanthin were found to be the major carotenoids. However, at intensity of 100 µmol m⁻² s⁻¹, there was decrease (green 1377.0 µg L⁻¹; red 826.86 µg L⁻¹). In lipid production, there was no significant change when 50 µmol m⁻² s⁻¹ was used. The yeast exhibited distinct behavior towards the LED; i.e., carotenogenic production was notably more accentuated, a fact that shows that adequate illumination is an effective strategy to increase carotenoid production. In this sense, it is concluded that the intensity of light and colors applied to microbial cultivation is extremely important, as it affects the metabolism of yeasts, leading to an increase in the production of carotenoids and causing a significant change in the profile of fatty acids produced.