_Applied_  
_sciences_  
_Hodottorula Strains Isolated from Seawater That Can_  
_Biotransformation Raw Glycerol into Docosahexaenoicenoic Acid (DHA)_  
and Carotenoids for Animal Nutrition_  
**[PERSON] \({}^{1,2,3,*}\), [PERSON] \({}^{1,2,3}\), [PERSON] \({}^{4}\) and [PERSON] \({}^{3}\)**  
\({}^{1}\) Doctorado en Ciencias con Mencion en Manejo de Recursos Acuaticos Renvables (MaReA),  
Facultad de Ciencias Naturales y Oceanograficas, Universidad de Concepcion, Concepcion 4070405, Chile; [EMAIL_ADDRESS]  
\({}^{2}\) Departamento de Oceanografia, Facultad de Ciencias Naturales y Oceanograficas,  
Universidad de Concepcion, Concepcion 4070405, Chile  
\({}^{3}\) Centro de Investigacion Oceanografia COPAS Sur-Austral, Facultad de Ciencias Naturales y Oceanograficas,  
Universidad de Concepcion, Concepcion 4070405, Chile; [EMAIL_ADDRESS]  
\({}^{4}\) EWOS Chile, Alimentos Ltd.a., Parque Industrial, Escuadron Km 20, Coronel 4190000, Chile; [EMAIL_ADDRESS]  
\({}^{*}\) Correspondence: [EMAIL_ADDRESS]; Tel: +56-41-2983651  
**Featured Application: Marine biomass of _Rhodotorula_ could be used as an alternative source of PUFAs and carotenoids for human and animal nutrition, using raw glycerol for their culture. **  
**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 bitotransforming 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. **  
**Keywords:**_Rhodotorula_ sp. ; docosahexaenoic acid (DHA); carotenoids; canthaxanthin; raw glycerol with regard to jurisdictional claims in published maps and institutional affiliations. **1. Introduction**  
_Rhodotorula_ species are pigmented basidiomycetous yeasts in the family _Sporidobicaceae_[1]. This genus contains 37 species, and only three of them, including _R. mucilaginousa_ (formerly _R. rubra_), _R. minuta_, and _R. glutinis_, have been reported as causes of infection in humans [2]. Most species of _Rhodotorula_ have been isolated from terrestrial ecosystems, which can metabolize diverse carbon sources. From the marine environment, the _Rhodotorula_ described: _R. glutinis_, _R. glutinis_ var. _dairiensis_, _R. aurantiaca_, _R. graminis_, _R. (mucilaginousa) rubra_, _R. pilmanue_, _R. minuta_ and _R. aureus_ are capable of metabolizing substrates such as galactose, lactose, maltose, sucrose, melibiose, raffinose, turnanose, melezitose and cane molasses [3, 4, 5], and _Rhodotorula glutinis_, _R. mucilaginousa_, and _R. gracilis_ are able to use glycerol and potato wastewater as a carbon source [6; 7; 8] but in low concentration of sodium (\(\leq\)1.1%). From the marine ecosystem of the Southeastern Pacific twelve strains of marine fungoids capable of producing DHA, EPA and carotenoid pigments have been isolated [9].