Effects of geometrical configurations of photobioreactors on the growth of marine benthic diatom Cylindrotheca closterium / Fotobiyoreaktörlerin geometrik konfigürasyonlarının sucul bentik diatom Cylindrotheca closterium üremesi üzerine etkisi

Abstract

Abstract Objective: For algal biotechnology, the primary barrier is the developing of cost effective photobioreactor operating in a high-efficiency. In this study, the effects of three different types of photobioreactors (bag, flat plate and bubble column) on the growth and sugar production of the diatom Cylindrotheca closterium were simultaneously investigated for 7 days of batch cultivation period. Methods: The photobioreactors were incubated at 21±2°C under the light intensity of 50 μmol photons m-2s-1 with a 12: 12 h light: dark cycle photoperiod at the air flow rate of 2 L min-1 for 7 days of batch productions. The turbidity (optical density), chlorophyll-a, exopolysaccharide (EPS) content and reducing sugar concentration were measured. Results: The maximum specific growth rate of 0.29 day−1, which corresponded to the doubling time of 2.40 day, was obtained in the bag photobioreactor cultivation of C. closterium. It was found that the polyethylene bag photobioreactors are suitable for the production of diatoms as a closed photobioreactor. Conclusion: The key is not only the selection of geometrical configuration of photobioreactor, but also the determination of the light penetration path for cost effective photobioreactor design operating in high efficiency related to the algal productions.