Studies on the production of useful chemicals, especially fatty acids in the marine diatom Nitzschia conspicua Grunow

Abstract

A local marine diatom, Nitzschia conspicua Grunow, was cultured in enriched synthetic seawater using flasks (agitated by magnetic stirring) and a 1.2 1 fermenter. Lipids, fatty acids, proteins, carbohydrates and ash of the flask cultures were determined at various stages of growth (day 3, 5, 7, 10, 13, 15 and 17). The fermenter culture was harvested during the stationary phase for similar chemical analyses. N. conspicua attained a higher biomass concentration during the stationary phase when cultured in the fermenter (188 mg dry weight 1 -) than in flasks (140-151 mg dry weight 1-'). However, both systems showed similar specific growth rates based on chlorophyll-a concentration. Appreciable amounts of the essential fatty acids 20:4 (0.6-4.7% total fatty acids) and 20:5 (1.9-4.7% total fatty acids) are present in this diatom. Maximal amounts of these fatty acids were produced after 7 days' growth (i.e. 2 days after the end of the exponential phase). Lipids, fatty acids, proteins, carbohydrates and ash varied with culture age in N. conspicua.

Influence of culture temperature on the growth, biochemical composition and fatty acid profiles of six Antarctic microalgae

“…The lipids were transesterified in 1% H 2 SO 4 in MeOH and the fatty acid methyl esters were analysed by gas chromatography as described by Chu et al (1994). Proteins were extracted in with 0.5 N NaOH (80 • C, 30 min) and the concentration determined by the dye-binding method (Bradford, 1976).…”

Influence of carbon source on growth, biochemical composition and pigmentation of Ankistrodesmus convolutus

“…Lipids were extracted by sonicating in methanolchloroform-water (2:1:0.8, v/v/v) and determined gravimetrically (Bligh & Dyer, 1959). The lipids were transesterified using 1 N sodium methoxide (60 C, 30 min) and the fatty acid methyl esters obtained were analysed by gas chromatography as described in Chu et al (1994a). Quantification of fatty acids was based on integrated areas (Chromatopac RC8A) of the peaks using the external standards consisting of 16:0, 18:0, 18:1, 18:2, 18:3 and 18:4 (Sigma Chemicals).…”

The Effect of Some Extracted Compounds From the Algae Oscillatoria Tenius Against Pathogenic Bacteria

“…So, the antibacterial activities of the algae tested could be attributed to the type and amount of free fatty acids which have a role in the overall defense against the studied pathogenic Gram-positive and Gramnegative. Terpenoid content considered to contribute to antibacterial activity 19,20 . The result of this study suggested that flavonoids could use clinically to treat patients with hypercholesterolemia and hypertension.…”