Abstract

Altaf AL-Rawi, Fikrat M. Hassan and Bushra M.J.Alwash

Ergosterol is one of the most important chemicals produced by algae, specifically by microalgae, and the Squalene is the commonly known as a precursor for biosynthesis of ergosterol. Coelastrella terrestris was isolated from sediment sample collected from the banks of Tigris River and the modified Chu 10 culture medium was used for algal growth and determining the optimum growth condition (25) °C and 268 µE. mˉ². secˉ¹). In an attempt to further maximize ergosterol production by C. terrestris. The optimal temperature and light growth conditions 30 ºC and 300 µE. mˉ².secˉ¹ were tested under of different Squalene concentrations treatments (0.1, 0.25, 0.5 and 1Ùª). This combined treatment of optimal culture conditions and Squalene was caused an extremely a highest ergosterol production recorded (533.3 ± 15.92 ppm) at 1% squalene in phase 2, while the lowest production (54.3 ± 2.48ppm) was at 0.10% Squalene in phase3. The present study has further investigated the potential antioxidant activity of C. terrestis crude extract and ergosteoleby the ability to scavenging free radical 2.2 diphenyl-1-picrylhydrzyl (DPPH). The results observed that antioxidant activity of algal crude extract was lower antioxidant as compared with the ergosterol and ascorbic acid (control), whereas antioxidant activity reached to 100% when used with crud extract the concentration (2000 µg/ml), ergosterol (50 µg/ml) and ascorbic acid (150 µg/ml). This study concluded that selectively combined culture conditions of 30ºC and 300 µE. mˉ². secˉ¹ could maximize the biomass of the newly recorded C. terristris and production of ergosterol. This study is the first test of the ability of C. terristris to produce ergosterol and antioxidant activity.