title: The effect of low light flux and nitrogen deficiency on the chemical composition of Spirulina sp. (Arthrospira) grown on digested pig waste.
abstract: Evaluation of the effect of low light flux and nitrogen deficiency on growth and chemical composition of Spirulina sp. (straight filaments strain, SF) in batch cultures utilizing a complex medium containing sea-water supplemented with anaerobic effluents from digested pig waste, was undertaken. Cultivation was carried out either at a light flux of 66 (lower) or 144 micromol photon m(-2) s(-1) (higher), utilizing bench raceways. Biomass concentration (as dry weight) after 12 days of cultivation in the complex medium was similar (P < 0.05) to the one observed in a chemically defined medium (Zarrouk), regardless of the light intensity. Protein content of the biomass in the complex medium was significantly lower (P < 0.05), compared to the Zarrouk medium, regardless of the light flux. However, biomass from the complex medium was enriched in total lipids (28.6%), when cultures were exposed to the lower light flux. On the other hand, the palmitoleic acid percentage of total fatty acids was significantly higher (P < 0.05) at a higher light intensity and a high level of gamma linolenic acid (GLA) as a percentage of total fatty acids was observed (28.13%) in the biomass harvested from the complex medium at the lower light intensity. Finally, polysaccharide content was significantly higher (P < 0.05) at the high light intensity and a very high content of total polysaccharides (28.41%) was observed in the complex medium.
authors.affiliation: Departamento de Biotecnología, Instituto de Ecología, Xalapa, Mexico. eugenia@ecologia.edu.mx
authors.forename: E J
authors.initials: EJ
authors.lastname: Olguín
authors.forename: S
authors.initials: S
authors.lastname: Galicia
authors.forename: O
authors.initials: O
authors.lastname: Angulo-Guerrero
authors.forename: E
authors.initials: E
authors.lastname: Hernández
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry*; D018533:Biomass; D003470:Culture Media / Q000494:pharmacology; D005227:Fatty Acids / Q000032:analysis; D005229:Fatty Acids, Monounsaturated / Q000032:analysis; D005243:Feces / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009584:Nitrogen / Q000172:deficiency*; D017785:Photons; D011134:Polysaccharides / Q000032:analysis; D012623:Seawater; D053545:Spirulina; D013552:Swine; D013997:Time Factors; D017965:gamma-Linolenic Acid / Q000032:analysis
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D011134:Polysaccharides; C008757:palmitoleic acid; D017965:gamma-Linolenic Acid; D009584:Nitrogen