Biosynthesis of highly unsaturated fatty acids by hydrocarbon degrading microorganisms

• Main Authors: MEHDI GHASEMI, YEMEN ATAKISHIYEVA
• Format: Article
• Language: English
• Published: Plovdiv University Press 2015-04-01
• Series: Journal of BioScience and Biotechnology
• Subjects: Cephalosporium humicola; Mucor globosus; Pythium irregulare; single cell oils; polyunsaturated fatty acids; omega; optimization
• Online Access: http://www.jbb.uni-plovdiv.bg/documents/27807/1014559/jbb_2015-4(1)-pages_81-93.pdf

Disruption of polyunsaturated fatty acids (PUFA) metabolism leads to many diseases. In this study, producers of γ-linolenic acid (GLA), arachidonic acid (ARA) and eicosapentaenoic acid (EPA) were selected: Cephalosporium humicola IE (on glucose, dry biomass – 14 g/l, total lipids – 18-20%, GLA in lipids – 12.0%), Mucor globosus 11 (respectively – 15 g/l, 18% and 5%) and Pythium irregulare LX (on glucose, dry biomass – 14.5 g/l, total lipids – 18-20%, 9.2 and 7.8% of ARA and EPA, respectively). On crude oil as the only source of carbon, the amount of biomass of the specified fungi decreases by 3-4 times, whereas the quantity of lipids and highly unsaturated fatty acids increases in four and 1.2 - 3.4 times, respectively. The maximum γ-linolenic acid in M. globosus and C. humicola was detected at neutral рН. Optimum volume of inoculate was 2.0-4.0%, nitrogen source NH4NO3, a carbon-nitrogen ratio 34:1. For biosynthesis of ARA and EPA by P. irregulare, the optimum nitrogen source was NH4Cl, рН 7.0- 8.0 and С/N - 50:1 at 28°C. The process of adaptation to stressful situation under crude oil motivated the increase of the rate of membrane phospholipids with high quantity of unsaturated fatty acids.