Effect of exposure to the different concentration of pure CO2 gas on growth rates and fatty acids metabolism of green Alga Chlorococcum humicola

الملخص EN

The current study examined the effects of the exposure to the different concentrations of the pure CO2 on the growth rates and fatty acids metabolism of the green algae Chlorococcum humicola that isolated locally.

The algae cells exposure into many concentrations of CO2 (25, 50, 75, 100% ) v/v of culture media which were (BG11, Chu13, Chu10) for growing.

The experiments were conducted in standard laboratory conditions such as temperature, lighting intensity, pH which were respectively (25±2°C, 3000 lux, 7.6) with lighting system 18: 16 hour(light: dark).

The supplementing of CO2 every 73 hour by the device (Gas-flow-meter).

The results were recorded daily for 18 days.

The results have shown that present responses in the growth rates of studied algal cells by all using cultures media that included in this study for growing the algae with best result in Chu13 media.

As well as, the present study found that many types of fatty acids in dry biomass of algal cells in vitro by using HPLC technique and recordedthe following fatty acids: Myristic C14: 0, Palmetic C16: 0, Plamitolic C16: 1, Arachidic C20: 4, Linoleic C18: 2 (Omega: 6), Oleic C18: 1(Omega 9).

The response value was changed betweenthe acids depending on the type of culture media and the following fatty acid: Palmetic C16: 09, Myristic C14: 0, Palmitolic C16: 1, Olic C18: 1 and Linolic C18: 2) recorded the values (440.64, 474.54, 987, 770, 1054.25, 455.64) mg/L dry weight respectively in two concentrations (100, 75 %) v/v when growing the algae in the culture media Chu1.

While the acid Arachidic C20: 4recorded highest value (684.35) mg/L in the culture media BG11 at 100 % concentration.