|Culture of the marine diatom Phaeodactylum tricornutum with different nitrogen sources: growth, nutrient conversion and biochemical composition|
Fidalgo, J.P.; Cid, A.; Abalde, J.; Herrero, C. (1995). Culture of the marine diatom Phaeodactylum tricornutum with different nitrogen sources: growth, nutrient conversion and biochemical composition. Cah. Biol. Mar. 36(3): 165-173
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723, more
|Authors|| || Top |
- Fidalgo, J.P.
- Cid, A.
- Abalde, J.
- Herrero, C.
Cultures of the marine diatom Phaeodactylum tricornutum were grown in nitrate, nitrite, ammonia or urea media. Nitrogen transformation efficiencies were close to I0O% in cultures with nitrate, nitrite or urea, with productivities in dry biomass between 2.2 g.1 super(-1) (urea) and 2.8 g.1 super(-1) (nitrate). However growth in ammonia cultures ceased due to a drop in pH of the medium. The biochemical profile was more affected by the growth phase than by the N source. Cellular contents of chlorophylle a and c decreased and the chlorophyll alc ratio increased when cultures entered the stationary phase. Protein and RNA were higher during exponentiel growth (about 30% and 8% ash free dry weight (AFDW), respectively), but carbohydrates increased up to 220% in the stationary phase. Although significant differences were observed in cellular contents, the biochemical composition (as % AFDW) of the nitrate, nitrite and urea-grown cells was very similar. The highest total fatty acids and polyunsaturated fatty acids (PUFAS) contents in the stationary phase were obtained in the urea-grown cells, with an eicosapentaenoic acid (EPA) content of 26.8 mg.g super()-1 of dry biomass.