Biodiesel prospective of five diatom strains using growth parameters and fatty acid profiles

Biomass productivity, lipid content, lipid productivity and fatty acid methyl ester (FAME) profiles of three pelagic and two benthic diatom strains (Chaetoceros calcitrans, Thalassiosira sp., Skeletonema sp., Navicula sp., Nitzschia sp.) were evaluated to identify potent strains for biodiesel production. Navicula sp. and Thalassiosira sp. were found to be higher biomass producing strains, whereas Nitzschia sp. showed lower biomass productivity. Lipid content was higher for Thalassiosira sp. and lower for Skeletonema sp. Navicula sp. was found to be the most suitable biodiesel feedstock in terms of saturated (65.59%) and monounsaturated (27.92%) fatty acids. Cluster analysis of the strains based on growth parameters and FAME profiles revealed close resemblance between Chaetoceros calcitrans and Skeletonema sp. and also between Thalassiosira sp. and Navicula sp. But Nitzschia sp. was secerned from the other strains. Principal Component Analysis (PCA) provided a confirmation that lipid content alone cannot be a reliable criterion for evaluating suitable feedstock. Multi-Criteria Decision Analysis (MCDA) based on Analytic Hierarchy Process (AHP) was successively utilized for strain selection, which identified Navicula sp. as the ideal biodiesel feedstock, followed by Thalassiosira sp. The study also found that Nitzschia sp. is inferior as a viable biodiesel feedstock.