No abstract

The thraustochytrid are marine heterotrophic protists that are widely distributed in the marine world. They are characterized by producing and accumulating great amount of lipids in their cells, especially long chain polyunsaturated fatty acids (LC-PUFA), highlighting the docosahexaenoic acid (DHA, 22:6, n-3), eicosapentaenoic acid (EPA, 20:5, n-3) and arachidonic acid (ARA, 20:4, n-6), as well as pigments of interest for human health and animal nutrition, such as carotenoids. Therefore, the objective of this study was to isolate and characterize three natives isolated of thraustochytrids and assess the potential of the by-products of the manufacture of beer (RB) and protein extraction of Lupine flour (RL) as complex carbon sources to produce biomass, lipid and polyunsaturated fatty acids. Three native strains of thraustochytrid (AS5-B2, IQ81 y VAL-B1), isolated from Chilean coastal waters were morphologically and genetically identified as thraustochytrid. For the determination of biomass production cultures were quantified by gravimetry and the fatty acids quantification and identification were carried out by gas chromatography (GC-FID). Our results show that the culture with any sources of complex carbon used, increased significantly the production of both biomass and total lipids in the strains IQ81 and VAL-B1, compared to glucose as pure carbon source. On the other hand, strain AS5-B2 showed a decrease in the total production of lipids in RB compared to the pure carbon source. For the production of fatty acids, the strains IQ81 and VAL-B1 showed a significant increase in DHA when growing in RB. In conclusion strains IQ81 and VAL-B1 can be used to biotransform industrial waste, such as RB and RL, into a more valuable product such as DHA, EPA, ARA and lipids.

Global utilization of long-chain polyunsaturated fatty acids (LC-PUFAs) has increased steadily in the last decade which has imposed a huge demand for fish oil as it is currently the only source capable of sustaining the enormous commercial requirements this input worldwide. They are currently using various microorganisms to produce single cells oil (SCO) high in LC-PUFAs, within which highlights the thraustochytrids (TH). The TH is a group of marine protists (pseudofungi) with capacity to produce LC-PUFAs such as eicosapentaenoic acid (EPA), docosapentaenoic (DPA) and docosahexaenoic acid (DHA). In this study the chilean VAL-B1 strain was grown in glucose, starch and glycerol being obtained biomass production and LC-PUFAs. Biomass values ​​obtained were 1.02 ± 0.32 g/L, 1.25 ± 0.44 g/L and 1.44 ± 0.27 g/L of glucose, glycerol and starch respectively. The profile of LC-PUFAs showed a percentage of omega-3 fatty acids on glucose of 59.34%, 61.50% in starch and glycerol of 47.86%. The greater this value was to omega-3 DHA when starch was used, with 68.16 mg/g being greater than 45.77 mg/g glycerol and 63.89 mg/g in glucose. Therefore, we conclude that VAL-B1 produces more biomass has greater value of omega-3 LC-PUFAs and greater concentration of DHA when starch is used as a source of substrate for cultures.