초록
<P>Here we tested the bioconversion of biodiesel-derived crude glycerol by the oleaginous red yeast <I>Sporidiobolus pararoseus</I> KM281507 in two bioreactors types (stirred-tank and airlift). High production yields (biomass, 10.62 ± 0.21 g/L; lipids, 3.26 ± 0.13 g/L; β-carotene, 30.64 ± 0.05 mg/L; total carotenoids, 46.59 ± 0.07 mg/L) were achieved in a 3.0 L airlift bioreactor under uncontrolled pH regimes (initial pH 5.63). Under optimized conditions (6.0 vvm aeration rate; 60 ± 5% constant dissolved oxygen [DO] maintained by flushing pure oxygen [O<SUB>2</SUB>] into the vessel; 10,000 Lux light irradiation) volumetric production in the airlift bioreactor was further increased (biomass, 19.30 ± 1.07 g/L; lipids, 6.61 ± 0.04 g/L, β-carotene, 109.75 ± 0.21 mg/L; total carotenoids 151.00 ± 2.71 mg/L). Production was also recorded at a <I>S. pararoseus</I> KM281507 growth rate of 0.16 ± 0.00 h<SUP>−1</SUP> (lipids, 0.94 ± 0.04 g/L/d; β-carotene, 15.68 ± 0.40 mg/L/d; total carotenoids, 21.56 ± 0.20 mg/L/d). Lipids from <I>S. pararoseus</I> KM281507 had a high unsaturated fatty acid content, with oleic acid (C18:1) accounting for 80% of all fatty acids. This high oleic acid content makes <I>S. pararoseus</I> KM281507 well-suited as a third generation biodiesel feedstock. Our findings show that airlift bioreactors are suitable for bioconversion of crude glycerol into lipids and carotenoids using <I>S. pararoseus</I> KM281507. This approach is advantageous because of its ease of operation, cost efficiency, and low energy consumption.</P>