Bioprocess engineering of cell and tissue cultures for marine seaweeds

Seaweeds are a rich source of valuable compounds including food additives and biomedicinals. The bioprocess engineering of marine macroalgae or "seaweeds" for the production of these compounds is an emerging area of marine biotechnology. Bioprocess technology for marine macroalgae has three elements: cell and tissue culture development, photobioreactor design, and identification of strategies for eliciting secondary metabolite biosynthesis. In this paper, the first two elements are presented. Firstly, the development of phototrophic cell and tissue culture systems for representative species within brown, green, and red macroalgae is described. In vitro culture platforms include microscopic gametophytes, undifferentiated callus filaments, and "microplantlets" regenerated from callus. Secondly, the controlled cultivation of these phototrophic culture systems in stirred tank, bubble-column, airlift, and tubular photobioreactors is described. Limiting factors on biomass production in photobioreactors including light delivery, CO2 transfer, and macronutrient delivery are compared. Finally, a mathematical model that integrates light delivery, CO2 delivery, and macronutrient delivery into the material balance equations for biomass production in a perfusion bubble-column photobioreactor is presented, and model predictions are compared to biomass production data for microplantlet suspension cultures of the model red alga Agardhiella subulata. (C) 2004 Elsevier B.V. All rights reserved.