An assessment of biopotential of three cyanobacterial isolates from Antarctic for carotenoid production

Specific growth rates and carotenoid contents of three Antarctic and tropical strains of cyanobacteria viz. Anabaena sp., Phormidium sp. and Nostoc sp. were compared in batch and mass cultures to assess bio-potential of Antarctic strains for cost-effective carotenoid production. Antarctic strains though exhibited slightly lower specific growth rates, but contained higher carotenoid contents (per unit dry wt.), than tropical strains. Modification of normal composition of BG-11 culture medium, by altering nitrogen and carbon sources resulted in 25-38% increase in carotenoid content in both types of strains. Mass-culture in indoor and semi-outdoor bio-reactors resulted in 39-113% higher carotenoid content in Antarctic strains, compared to their respective tropical strains. The observations suggest that Antarctic cyanobacteria may have potential as superior strains for maximizing the yield of carotenoids.