Fatty acid Compositions of two Microalgae Species used in Mariculture in Bahrain: A New Source of Microalgae for Aquaculture

Abstract

The microalgal Chlorella sp. and Isochrysis galbana strains that have been used by the National Mariculture Centre in Bahrain to rear aquatic animals since the 1980s were investigated for fatty acid compositions. The results of the strain identification have confirmed the identity of the strain Isochrysis galbana and corrected the identity of the strain Chlorella sp. to Picochlorum sp. The fatty acids profile has shown that polyunsaturated fatty acids (PUFAs) were the major forms of fatty acids in both species. The most abundant PUFAs were C18:4n3, and 18:2n-6 in Picochlorum sp., and C18:4n3, C22:5n3, and C18:3n6 in Isochrysis galbana. Omega 3 fatty acids (38.56±1.76%) were higher in Isochrysis galbana in comparison with Picochlorum sp. (16.89±3.63%); whereas omega 6 fatty acids were higher in Picochlorum sp. (36.53±1.91%) than in Isochrysis galbana (22.30±0.86%).The sum of EPA and DHA was 8.26±0.50% and 6.56±0.47% in Isochrysis galbana and Picochlorum sp. respectively. The n-6/n-3 fatty acids ratio was 0.58 for Isochrysis galbana and 2.16 for Picochlorum sp. Our results suggest that both strains can be considered as a good food source for commercial production in aquaculture and that the mixing of both species will provide a balanced nutrition for animal growth in aquaculture.