Production of carbonic anhydrase by marine and freshwater microalgae

Abstract

Microalgal biomass is a potentially attractive source of several bioproducts, such as carbonic anhydrase, the enzyme responsible for catalyzing the reversible hydration of CO2. This biomolecule has been studied for its application in enzymatic systems of CO2 capture and sequestration. Therefore, the aims of this study were to evaluate the production of carbonic anhydrase in the culture of marine and freshwater microalgae and to monitor the growth in terms of biomass and pH. The marine microalgae Dunaliella tertiolecta, Tetraselmis suecica, Phaeodactylum tricornutum, Isochrysis galbana and Nannochloropsis oculata, and the freshwater microalgae Chlorella vulgaris and Scenedesmus obliquus were cultured in Erlenmeyer flasks at 25 °C. The freshwater microalga that had the highest enzyme production was C. vulgaris: its maximum activity was 44.0 U/L. Among the marine microalgae, P. tricornutum stood out as the best producer, with a maximum activity of 19.9 U/L. In terms of specific activity, the highest values were obtained from D. tertiolecta (44.6 U/g) and P. tricornutum (24.5 U/g). These results show the potential of microalgae to produce the carbonic anhydrase enzyme. Microalgal biomass represents an attractive source of this biomolecule.