جستجوی مقالات مرتبط با کلیدواژه "اسیدهای چرب غیراشباع بلند زنجیره" در نشریات گروه "زیست شناسی"

Introduction A wide variety of oleaginous yeast and their productions have been used as dietary supplements in food and feed productions. Fatty acid profiles and lipid of oleaginous yeast strains were highly influenced by physic-chemical conditions of medium Material and method Pichia kudriavzevii isolated from the gill of pike perch was capable enough to produce a high quantity of lipid and polyunsaturated fatty acids (PUFA).One factor at time was used to investigate the effect of various selected substrates on growth and lipid production by Pichia kudriavzevii in batch fermentation, subsequently the key substrates were optimized for lipid, biomass, and phenolic components production by using response surface methodology. Results The results of RSM indicated that maximum lipid (28 percentage of dry weight biomass) and phenolic component (2.25 mg gallic acid /g of dry biomass) were achieved in media that had 60 g/l glucose and 9 g/l protein resources. Dry weight biomass which had the highest content of lipid produced the most phenolic components with the highest antioxidant activity (50 % Inhibition).Pichia kudriavzevii’ lipid mainly consisted of palmitic acid (21.7%), oleicacid (33.2%) and linoleic acid (23.2 %), pointing that these fatty acids could be considered a reliable source of biodiesel production. Discussion and conclusion The maximum content of phenolic components and lipid production were obtained in the same medium. To minimize the lipid oxidation, yeast was stimulated for high phenolic components production which had the highest antioxidant activity to prevent the accumulated lipid from oxidation. Overall, temperature reduction by varying methods had a significant impact on fatty acids profile of Pichia kudriavzevii lipid so that it could be regarded not only as biodiesel but also PUFAs sources.

Oleaginous yeasts could produce lipid with high contents of poly unsaturated fatty acids (PUFA). Isolation of oleaginous species with a strong ability to produce lipid and long-chain polyunsaturated fatty acid (LCPUFA) could be considered as an effective step to the commercialization of LCPUFA production. Having isolated an oleaginous yeast species from fish, the species were identified by the molecular method. One factor at time and response surface methods was used for optimization of lipid and oleic acid production. Fermentation was being conducted in five days. The yeast specie which isolated from the gills of trout fish was Wickerhamomyces Siamensis SAKSG. Response Surface Methodology (RSM) indicated that optimal conditions for lipid production (27% of dry biomass) was obtained at the middle levels of glucose (42 g/L) and minimum amount of soy bean (5 g/L). The optimal amount of oleic acid (66.5% of lipid) was obtained at high levels of glucose (80 g/L) and soybean (15 g/L). Docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (ARA) were also produced by this new isolated yeast. Discussion and conclusion: Wickerhamomyces SiamensisSAKSG as oleaginous yeast had great ability to produce lipid with a reasonable amount of LCPUFA. Chemical condition of media highly impact on LCPUFA production. More to the point, protein had positive effect to LCPUFA production via stimulation of the yeast growth.