title: Nitrogen effects on proteins, chlorophylls and fatty acids during the growth of Arthrospira platensis.
abstract: Spirulina platensis (=Arthrospira platensis) is a tunisian strain which has been isolated for the first time in Oued Essed (Sousse, Sidi Bou Ali). Biomass evolution, proteins, chlorophylls and fatty acids composition of this alga were monitored by varying nitrogen concentrations in the culture medium. Nitrogen stress was provoked by adding sodium nitrate (NaNO3) in the culture medium with concentrations varying from 0 to 5 g/l. Results obtained showed that nitrogen depletion increased total proteins and total chlorophylls. The addition of NaNO3 (5g/l) led to an increase of total fatty acids amounts and modify fatty acids composition. Optimal quantities of palmitic, gamma -linolenic and oleic acids were obtained with NaNO3 free-cultures. Thus, the tunisian strain has valuable biological substances, worthy to determine the optimal conditions for its propagation.
authors.affiliation: Centre de Biotechnologie, Technopole de Borj-Cedria, Unité des Plantes Aromatiques et Médicinales, Tunisie. chebsamah@yahoo.fr
authors.forename: Samah
authors.initials: S
authors.lastname: Ayachi
authors.forename: Amor
authors.initials: A
authors.lastname: El Abed
authors.forename: Wissal
authors.initials: W
authors.lastname: Dhifi
authors.forename: Brahim
authors.initials: B
authors.lastname: Marzouk
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis*; D018533:Biomass; D002734:Chlorophyll / Q000096:biosynthesis*; D005227:Fatty Acids / Q000096:biosynthesis*; D009566:Nitrates / Q000378:metabolism / Q000494:pharmacology; D009584:Nitrogen / Q000378:metabolism*; D053545:Spirulina / Q000254:growth & development* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D005227:Fatty Acids; D009566:Nitrates; D002734:Chlorophyll; C031618:sodium nitrate; D009584:Nitrogen