title: Production of eicosapentaenoic acid by Nannochloropsis oculata: Effects of carbon dioxide and glycerol.
abstract: The marine microalga Nannochloropsis oculata is a potential source of eicosapentaenoic acid (EPA, C20:5n3) and carotenoids for use in functional foods and nutraceuticals. Mixotrophic culture of N. oculata using glycerol was examined as a possible way of increasing the biomass and metabolite productivity relative to a pure photoautotrophic culture in modified f/2 medium. The effect of CO2supply was also tested. EPA production in semi-continuous culture with and without glycerol and CO2was evaluated. The effects of glycerol supplementation and light/dark cycling on the production of the biomass and EPA are reported for cultures conducted at a constant pH controlled using CO2. Consumption of glycerol was small, but its effects were significant. Glycerol enhanced the lipid content of the biomass but reduced the chlorophyll a content. Mixotrophic cultivation favored the production of lipids with a high percentage of saturated fatty acids that are generally desired in oils for making biodiesel. EPA concentration (5.3±0.6 to 27.5±1.6mg EPA/L) in N. oculata cultures depended strongly on growth conditions. The highest EPA concentration occurred in non-aerated mixotrophic culture with intermittent CO2supply without pH control. This EPA concentration (=27.5±1.6mg/L) was comparable to that obtained in semi-continuous culture without glycerol and pH control, and aerated with CO2enriched air during the light period (=23.6±1.1mg/L).
authors.affiliation: Department of Chemical Engineering and Center of Food Biotechnology and Bioseparations, BIOREN, Universidad de La Frontera, Casilla 54-D, Temuco, Chile; Centre for Biotechnology and Bioengineering (CeBiB), Universidad de La Frontera, Temuco, Chile. Electronic address: carolina.shene@ufrontera.cl.
authors.forename: Carolina
authors.initials: C
authors.lastname: Shene
authors.affiliation: School of Engineering, Massey University, Private Bag 11 222, Palmerston North, New Zealand.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Chisti
authors.affiliation: Department of Chemical Engineering and Center of Food Biotechnology and Bioseparations, BIOREN, Universidad de La Frontera, Casilla 54-D, Temuco, Chile.
authors.forename: Daniela
authors.initials: D
authors.lastname: Vergara
authors.affiliation: Department of Chemical Engineering and Center of Food Biotechnology and Bioseparations, BIOREN, Universidad de La Frontera, Casilla 54-D, Temuco, Chile.
authors.forename: César
authors.initials: C
authors.lastname: Burgos-Díaz
authors.affiliation: Department of Chemical Engineering and Center of Food Biotechnology and Bioseparations, BIOREN, Universidad de La Frontera, Casilla 54-D, Temuco, Chile.
authors.forename: Mónica
authors.initials: M
authors.lastname: Rubilar
authors.affiliation: Department of Chemical Engineering and Center of Food Biotechnology and Bioseparations, BIOREN, Universidad de La Frontera, Casilla 54-D, Temuco, Chile.
authors.forename: Mariela
authors.initials: M
authors.lastname: Bustamante
mesh_terms: D019149:Bioreactors; D002245:Carbon Dioxide / Q000378:metabolism*; D015118:Eicosapentaenoic Acid / Q000032:analysis / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism*; D058009:Stramenopiles / Q000378:metabolism*
chemical_list: D002245:Carbon Dioxide; D015118:Eicosapentaenoic Acid; D005990:Glycerol
keywords: Carotenoids; Eicosapentaenoic acid; Lipids; Mixotrophic culture; Nannochloropsis oculata; Polyunsaturated fatty acids