The challenge of scaling up photobioreactors: Modeling and approaches in small scale. Issue 7 (13th May 2016)

• Record Type: Journal Article
• Authors: Socher, Maria Lisa; Löser, Christian; Schott, Carolin; Bley, Thomas; Steingroewer, Juliane
• Is Part Of: Engineering in life sciences. Volume 16:Issue 7(2016)
• Page Start: 598
• Page End: 609
• Publication Date: 2016-05-13
• Subjects: Arthrospira platensis -- Flat‐panel bioreactor -- Modeling -- Photobiotechnology -- Respiration Activity Monitoring System (RAMOS); Bioengineering -- Periodicals; 660.605
• DOI: 10.1002/elsc.201500134
• Languages: English
• ISSNs: 1618-0240

Abstract

Abstract : Commercial large‐scale application of photobiotechnology calls for acceptable rates and high cell densities. The latter results in self‐shading and a temporally declining growth rate, making the process inefficient. Upscaling phototrophic processes requires knowledge of the reaction kinetics with special attention on the μ ‐ I relation. Model‐based calculations for studying the effect of self‐shading on growth were performed for three μ ( I ) concepts. The nonrealistic μ ( I 0 ) concept results in exponential growth without limit, the widely used μ ( I ( x ) ) ¯ concept exhibits a growth behavior that significantly deviates from real processes, but the sophisticated μ ( I ( x ) ) ¯ concept describes real processes best. A Respiration Activity Monitoring System (RAMOS) with CultiLux unit was tested regarding its applicability for exploring the μ ‐ I dependency of Arthrospira platensis . The results were not satisfactory because of self‐shading due to a high cell density (which was essential for yielding detectable oxygen‐evolution signals). An innovative cultivation system in which self‐shading does not interfere with phototrophic growth was required. A flat‐panel system was constructed (designed by CFD, short light path of 1 cm, uniform planar light supply by LED and OLED units), allowing continuous cultivation of phototrophic microbes at varied light intensities.