Growth characteristics of three benthic dinoflagellates in mass culture and their antioxidant properties

Abstract

Background and Objective: Benthic dinoflagellates are potentially useful for many biomedical and toxicological applications. Amphidinium carterae (JHWAC), Prorocentrum rhathymum (JHWPMX1) and Symbiodinium sp. (JHLSD1) isolated from Jeju island, Korea were cultured in a photobioreactor to evaluate the growth performances in two culture media (IMK and f/2) with three different concentrations (1X, ½X and ¼X) and to determine their proximate chemical compositions and potential antioxidant effect. Methodology: Growth was examined based on cell counts and biomass was determined as dry weight. The antioxidant effect was monitored using Electron Spin Resonance (ESR) spectroscopy in terms of radical scavenging activity. Results: Amphidinium carterae (JHWAC) showed significantly higher cell density (68.91×103 cells mL−1), growth rate (0.473 division day−1) and biomass (0.226 g L−1 dry weight) production in the 1X f/2 medium, whereas P. rhathymum (JHWPMX1) and Symbiodinium sp. (JHLSD1) showed best performances in the 1X f/2 and 1X IMK media, respectively. This reveals that the 1X f/2 medium can maximize the cell density and biomass of A. carterae (JHWAC) and P. rhathymum (JHWPMX1), whereas the 1X IMK medium does the same for Symbiodinium sp. (JHLSD1) in mass culture in a photobioreactor. Among the proximate chemical compositions of cultured strains, A. carterae (JHWAC) showed significantly higher crude carbohydrates (25%), proteins (21.5%) and lipids (6.3%). Conclusion: Among the methanol extracts of cultured dinoflagellates, A. carterae (JHWAC) showed the highest alkyl, DPPH and hydroxyl radical scavenging activities at IC50 values of 0.68±0.44, 1.40±0.54 and 1.67±0.38 mg mL−1, respectively.