Growth and lipid levels of Tetraselmis tetrahele and Nannochloropsis sp. cultured under commercial fertilizers

Abstract

Microalgae are aquatic photosynthetic organisms that contain high amounts of lipid and are potential sources of biofuels as well as feed additives for aquaculture. This study analyzed the growth and algal lipid content of two microalgae species (Tetraselmis tetrahele and Nannochloropsis sp.) using commercial fertilizers and nutrient enrichment. The samples were cultured for 5 days in 1 L dextrose bottles fertilized using Tongkang Marine Research Laboratory (TMRL) enrichment media, inorganic fertilizers such as 14-14-14, and a combination of 14-14-14 and 21-0-0. The relative growth rate of two algae were measured by computing the k value while the lipid components were extracted using the Bligh and Dyer Method, and the lipid content of each sample was determined using the gravimetric method. The use of 14-14-14 fertilizer produced the highest growth rates (k=1.810) and lipid composition (14.789%) for T. tetrahele. By contrast, Nannochloropsis sp., grew well under TMRL enrichment media (k=9.708), and the use of 14-14-14 fertilizer resulted to high lipid content (5.000%).