OUTDOORS BATCH CULTIVATION OF MARINE MICROALGAE Nannochloropsis sp USING PARALLEL GLASS TUBULAR PHOTOBIOREACTOR

Abstrak

ABSTRACT
Microalgae Nannochloropsis sp is autotrophic organism that can utilize atmospheric CO2 and sunlight
for growth via photosynthesis. It is potential sources for biodiesel due to its high lipid content. For
mass production, two basic designs of photo-bioreactor are available, i.e. open and enclosed systems.
Study was conducted to investigate the growth performance of Nannochloropsis sp in outdoor batch
culture system using Parallel Enclosed Glass-Tubular Photo-bioreactor (PBR) for 18 days with
modified f/2 medium. Nutrient N-P was calculated based on the empiric structure of microalgae cell
(C1O0.48H1.83N0.11P0.01) with target of biomass yield was 1gL-1. Temperature, pH, Optical Density (OD),
Dry Cell Weight (DCW), population, lipid content, and fatty acid were observed. Data showed that
temperature fluctuated between 22oC and 35oC, pH was stable at 7.0-7.5, OD increased from 0.134 to
0.878, DCW increased 39 times higher than its initial value. At the 18th day, the cell diameter varied
in range of 1-9 μm, cell weight increased 5.3 times (3.5 to 18.4 pg.cell-1), and lipid content is 35.71%.
Fatty acid was composed by saturated fatty acids (92.39%) that covered of lauric (20.30%), myristic
(12.69%), palmitic (50.05%), and stearic (9.35%) that was suitable for biodiesel. Unsaturated fatty acid
was performed by oleic acid (3.49%).
Key words: CO2 mitigation, biodiesel, Nannochloropsis sp, photo bioreactor