LIPID ACCUMULATION OF SKLETONEMA COSTATUM UNDER SILICA, NITROGEN AND AERATION STRESSTutik Nurhidayati, Aini Ika Rahmawati, Endang Purwanti Setyaningsih,Kristanti Indah Purwani, Edwin Setyawan and Nurul Jadid
Micro algae are photosynthetic microorganisms that could potentially be a source of raw material for bio diesel because it contains triglycerides. Skeletonema costatum was a micro algae that produces lipids up to 7.42%.Nutrients granted for micro algae growth. Aeration created water circulation so that cells obtained nutrients in the medium cultivation. The purpose of this study was to determine the effect of aeration and nutrient stress (N and Si) on growth and lipid content of S. costatum microalgae. Method starting from preliminarytest of S. costatum culture with different fertilizer concentration and 0 hour, 24 hours, and 48 hours aeration.Cell density calculations used to figure growth curves out. Biomass measurement obtained from 8 liter culture result. Factorial randomized design followed by ANOVA test. Lipid accumulation analyzed using fluorescence microscope. N1Si1, N2Si1, and N3Si1 were the treatment that produced high cell density.Growth of N1Si1 in 24-hours aeration was the highest cell density among the three aeration treatments.Yellow luminescence was present in the treatment of N2Si2 (KNO3 37.5 g/L and Na2SiO3 15 g/L) with 48hour of aeration, N2Si3 (KNO3 37.5 and Na2SiO3 0 g/L) and N3Si3 (KNO3 0 g/L and Na2SiO3 0 g/L) with 24 Hours Aeration.