Biomass and Lipid Production of newly isolated tropical marine microalgae Nannochloropsis sp.UHO3 and Skeletonema sp.UHO29 in outdoor raceway ponds Indrayani Indrayani1*, Haslianti Haslianti2, Asmariani Asmariani3, Ardiansyah4
1Study Programme of Agricultural Technology Education, Faculty of Engineering, University Negeri Makassar, Parangtambung Campus, Makassar 90224, South Sulawesi, Indonesia-
2 Department of Fisheries Products Technology, Faculty of Fisheries and Marine Sciences, University of Halu Oleo, Kendari 93232, Southeast Sulawesi, Indonesia-
3 Fisheries Laboratory, Faculty of Fisheries and Marine Sciences, University of Halu Oleo, Kendari 93232, Southeast Sulawesi, Indonesia-
4 Aquaculture Department, Agricultural Polytechnic State of Pangkep, Makassar-ParePare Km. 83, South Sulawesi, Indonesia-
Abstract
The microalgae Nannochloropsis sp.UHO3 and Skeletonema sp.UHO29 are newly isolated marine microalgae from coastal areas in Kendari, Southeast Sulawesi Indonesia. Indoor studies of the microalgae showed potential as biodiesel feedstock due to their high growth rates and high biomass and lipid productivity. However, for commercial uses especially for biodiesel feedstock, the species should have the ability to perform well under real outdoor conditions. The aim of this study was to determine growth, biomass and lipid productivity of the Nannochloropsis sp. UHO3 and Skeletonema sp.UHO29 in outdoor raceway ponds. The species were cultured using 1m2 raceway ponds. The two species were cultured using sea water based media enriched with f / 2 nutrients for Skeletonema sp. and Walne media for Nannochloropsis sp. Cultures were initially operated in batch mode until it reached the stationary phase. After that the culture is operated in a semi-continuous mode by harvesting part of the culture then adding new media as much as the volume of culture that is harvested. Cultures were maintained for about 3 months. The results of this study showed that the two species of microalgae have the ability to grow well in outdoor raceway ponds. The specific growth rate of Nannochloropsis sp.UHO3 ranged from 0.105 to 0.447 d-1 while the specific growth rate of Skeletonema sp.UHO29 ranged from 0.127 to 0.457 d-1. Nannochloropsis sp.UHO3 and Skeletonema sp.UHO29 have high lipid content ranging from 15-44% AFDW and 14-53% AFDW, respectively. The biomass productivity of Nannochloropsis sp.UHO3 and Skeletonema sp.UHO29 range between 10-122 gm-2.d-1 and 13-107 gm-2.d-1 while the lipid productivity value for Nannochloropsis sp.UHO3 ranges from 4 to 31 gm-2.d-1 and Skeletonema sp.UHO29 range from 5 - 25 gm-2.d-1. The results of the analysis of acid composition showed that palmitic acid (C16: 0), stearic acid (C18: 0), oleic acid (C18: 1) and linoleic acid (C18: 2) were the main components of fatt
