PRODUCTION OF BIODIESEL FROM SOYBEAN FRYING OIL USING NATIVE STRAINS OF Thraustochytrids

Abstract

Thraustochytrids are marine heterotrophic protists classified as oleaginous microorganisms, which use substrate as glucose, glycerol, complex organic matter and carbon-rich residues to generate fatty acid methyl esters (FAMEs). Thraustochytrids can be potentially used to produce biodiesel because their biomass is rich in lipids. This study evaluated three strains isolated from the Chilean coast: AS4A1, VALB1 and IQ81. The biochemical profile shows that VALB1 in glycerol produces mainly palmitic acid (26%), whereas IQ81 and AS4A1 have high values of oleic acid (38 and 39%). These were grown in glycerol (GLI) and residual glycerol (GR) obtained from the production of biodiesel from soybean frying oil (BAFS). Cultures of the thre  compared with BAFS. The profile of BAFS was calculated by adding SFA and MUFAs values and resulted in 30.70%. Regarding the AS4A1 strain in GR, this value reached 38.14%, with a biomass concentration of 13.62 g L-1. VALB1 presented values of 32.61% in GR and a biomass 6.07 g L-1, whereas IQ81 recorded values of 49.56% in GR and a biomass concentration of 5.28 g L-1 .The results show that AS4A1 generates higher biomass concentration and presents similar values with BAFS in SFA and MUFAs using GR. This indicates that this residue is a potential self-regulating alternative for the production of biodiesel and the first report of the use of soybean frying oil bioconverted by Thraustochytrids, cyclically using all GLI formed.