Analysis of the lipid content of micro algae species used in Philippine aquaculture for their potential in biodiesel production

Abstract

This study looked into the proximate lipid content of four micro algal species (<i>Chaetoceros calcitrans, Tetraselmis tetrahele, Nannochloropsis sp., and Chlorella sp<i/>) and one macrophyte <i>(Chaetomorpha sp.)<i/> commonly used in Philippine aquaculture. Prior to the proximate analysis using the method described by Bligh and Dyer (1959), the four micro algal species were cultured for five days in 1 L vessels fertilized with TMRL enrichment media. Proximate gravimetric analysis showed that the average lipid content of <i>Tetraselmis tetrahele<i/> at 24.11% was significantly higher <i>(p < 0.01)<i/> when compared to all the algal species tested. Comparing the mean lipid content of all micro algal species against that of the macrophyte also revealed a significantly higher <i>(p < 0.01)<i/> lipid content at 17.40%. Growth rates for all the micro algal species over the culture period was also measured, with the highest growth rate exhibited by <i>T. tetrahele<i/> at 1.15 divisions per day. Projected estimates for micro algal production yields of oil from a 1-hectare pond at 0.5 m depth were also calculated from the lipid analysis data, a showing that the highest yield of oil (7.29 tons) can be attained by culturing <i>T. tetrahele<i\>. This number was higher than estimated reports for oil production from an area of 1 hectare dedicated to either jatropha (1.7 tons) or coconuts (5.0 tons). This makes the culture of micro algal species a potential option for producing feedstock for biodiesel production.