Rhodotorula Strains Isolated from Seawater That Can Biotransform Raw Glycerol into Docosahexaenoic Acid (DHA) and Carotenoids for Animal Nutrition

Abstract

Due to the overexploitation of industrial fisheries, as the principal source of fish oil, as well as the increasing replacement of synthetic pigments for animal nutrition, we need to find sustainable sources for these essential nutrient productions. Marine Rhodotorula strains NCYC4007 and NCYC1146 were used to determine the biosynthesis of docosahexaenoic acid (DHA) and carotenoids by biotransforming raw glycerol, a waste product of biodiesel. To evaluate the presence of inhibitory substances in raw glycerol, both strains were also grown in the presence of analytical grade glycerol and glucose as the main carbon source separately. With raw glycerol, NCYC4007 showed a significant correlation between DHA production and intracellular phosphorous concentrations. NCYC1146, a new Rhodotorula strain genetically described in this work, can produce canthaxanthin but only when glycerol is used as a main carbon source. Then, NCYC4007 could synthesize DHA as a phospholipid, and the production of canthaxanthin depends on the kind of carbon source used by NCYC1146. Finally, malate dehydrogenase activity and glucose production can be used as a proxy of the metabolisms in these marine Rhodotorula. This is the first evidence that marine Rhodotorula are capable of synthesizing DHA and canthaxanthin using an alternative and low-cost source of carbon to potentially scale their sustainable production for animal nutrition.

Analysis of Ecological Role and Biotechnology Potential of Marine Yeast Rhodotorula sp. in Mangrove Forest of Pari Island, Jakarta

“…This yeast can also produce a range of valuable metabolites, including pigments, ergosterol, lipids, and polysaccharides (Byrtusová et al, 2021). Besides, Rhodotorula yeast is capable of producing isobutene (Fujii et al, 1987), antibacterial pathogens (Hartati et al, 2017;Vidya et al, 2022) Li, et al, 2022;Maza et al, 2020), bio-emulsifier (Oloke & Glick, 2005), plant growth promoters (Hartati et al, 2019), omega-3 fatty acids (Pino-Maureira et al, 2021), exopolysaccharides (Silambarasan et al, 2019), as well as biosurfactants (Gharaghani et al, 2019). The carotenoids produced by Rhodotorula yeast are increasingly being utilized as a replacement for synthetic carotenoids as supplements in poultry feed to increase poultry productivity (Grigore et al, 2023).…”

Microbial valorization of underutilized and nonconventional waste streams

“…A recent study found that the production of microbial lipids and carotenoids from waste frying oil (WFO) derived glycerol in Rhodotorula sp. had no inhibitory effects relative to pristine glycerol (Pino-Maureira et al., 2021 ). It is likely that differences in the waste stream, culture conditions, microbial host, or some combination are causing these discrepancies and warrant further investigation.…”

Microalgae, Seaweeds and Aquatic Bacteria, Archaea, and Yeasts: Sources of Carotenoids with Potential Antioxidant and Anti-Inflammatory Health-Promoting Actions in the Sustainability Era

“…Pigmented Rhodotorula spp. strains that accumulated intracellular carotenoids were also isolated from seawater near Chile [ 234 ]. One of the strains accumulated carotenoids, representing 19% of its dry weight, when cultured in glycerol as the only carbon source.…”