The effects of irradiation and microfiltration on the cells growing and total lipids production in the cultivation of Rhodotorula glutinis

The results of this study indicate that the irradiation could enhance the cells growing of Rhodotorula glutinis to 54.2 ± 1.6 g/L as compared to the control (without irradiation) of 38.3 ± 1.2 g/L. However, different wavelength of LEDs’ (red, green, blue and white) had no significant impacts on the growth and on the lipid content. The accumulation of potential inhibitive metabolic products probably impedes growth, which restricts more biomass accumulated in the fed-batch operation with irradiation. The combining of the fed-batch operation with irradiation and microfiltration can successfully improve the growth of R. glutinis to the maximum of 72.4 ± 0.6 g/L and 51.2 ± 4.9% of lipid content obtained. Conclusively, the integration process of a fed-batch operation, irradiation and microfiltration can effectively enhance cell growth in R. glutinis, without any reimbursement of lipid contents. This finding might be useful when applied to the commercialized cultivation of R. glutinis for biodiesel production.