원문정보
초록
영어
This study was to increase lipid and reducing sugar contents of Chlorella sp. by pulse feeding of nitrogen deficient medium (10 mg/L of NaNO3 and dissolved carbon dioxide from oyster wastes. Marine microalgal strain, Chlorella sp. was grown in a 14L photobioreactor with continuous illumination. Maximum cell concentration of 4.03 g-dry wt./L was obtained at 10 mg/L of NaNO3 and 3% (v/v) of carbon source medium at 0.5L/day of pulse feeding rate. Under this condtion, biomass contained total lipid and reducing sugar concentration as 33.6 (%, w/w) and 23.3 (%, w/w), respectively. However, for continuous feeding cultivations, maximum cell concentration of 5.01 g/L, 21.6 (%, w/w) of lipids and 23.9 (%, w/w) of reducing sugar content, respectively. In general, total lipids in the cell were increased under low nitrogen condition and cell growth and total reducing sugar was decreased under low nitrogen condition. However, under pulse-fed cultivation, cell growth rate and lipid content were lower than those from continuous cultivation, but the reducing sugar concentration were increased. This result implies that pulse-feeding of nitrogen and carbon sources should be simultaneousl increased cell growth, lipids and reducing sugars by controlling cell metabolisms, which could provide a way of economic production of both biodiesel and bioethanol from marine algae.