The influence aeration and light intensity could have on biomass production and protein biosynthesis in a Spirulina sp. isolated from an oil-polluted brackish water marsh is examined. Biomass, proximal composition and amino acid composition obtained from aerated cultures of the organism were compared with non-aerated cultures after a 35 days incubation period. Cultures of the organism were also grown in ordinary sunlight, and artificial light intensities of ca.7.5 and 15 mEm-2 S -1. Results showed that both aeration and exposing the cultures of the organism to artificial illumination improved biomass production and protein biosynthesis in the Spirulina sp. compared to sunlight illuminated and non aerated cultures. These results would be useful in optimizing growth conditions for maximum biomass and protein yields from the organism.