Biofilm growth of Chlorella sorokiniana in a rotating biological contactor based photobioreactor. Issue 12 (5th August 2014)

• Record Type: Journal Article
• Authors: Blanken, W.; Janssen, M.; Cuaresma, M.; Libor, Z.; Bhaiji, T.; Wijffels, R. H.
• Is Part Of: Biotechnology and bioengineering. Volume 111:Issue 12(2014:Dec.)
• Page Start: 2436
• Page End: 2445
• Publication Date: 2014-08-05
• Subjects: Biotechnology -- Periodicals; Bioengineering -- Periodicals; 660.6
• DOI: 10.1002/bit.25301
• Languages: English
• ISSNs: 0006-3592

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>ABSTRACT</title> <sec id="bit25301-sec-0001" sec-type="section"> <p>Microalgae biofilms could be used as a production platform for microalgae biomass. In this study, a photobioreactor design based on a rotating biological contactor (RBC) was used as a production platform for microalgae biomass cultivated in biofilm. In the photobioreactor, referred to as Algadisk, microalgae grow in biofilm on vertical rotating disks partially submerged in a growth medium. The objective is to evaluate the potential of the Algadisk photobioreactor with respect to the effects of disk roughness, disk rotation speed and CO<sub>2</sub> concentration. These objectives where evaluated in relationship to productivity, photosynthetic efficiency, and long‐term cultivation stability in a lab‐scale Algadisk system. Although the lab‐scale Algadisk system is used, operation parameters evaluated are relevant for scale‐up. <italic>Chlorella Sorokiniana</italic> was used as model microalgae. In the lab‐scale Algadisk reactor, productivity of 20.1 ± 0.7 g per m<sup>2</sup> disk surface per day and a biomass yield on light of 0.9 ± 0.04 g dry weight biomass per mol photons were obtained. Different disk rotation speeds did demonstrate minimal effects on biofilm growth and on the diffusion of substrate into the biofilm. CO<sub>2</sub> limitation, however, drastically reduced productivity to 2–4 g per m<sup>2</sup> disk surface per day. Productivity could be maintained over a period of 21 weeks without re‐inoculation of the Algadisk. Productivity decreased under extreme conditions such as pH 9–10, temperature above 40°C, and with low CO<sub>2</sub> concentrations. Maximal productivity, however, was promptly recovered when optimal cultivation conditions were reinstated. These results exhibit an apparent opportunity to employ the Algadisk photobioreactor at large scale for microalgae biomass production if diffusion does not limit the CO<sub>2</sub> supply. Biotechnol. Bioeng. 2014;111: 2436–2445. © 2014 Wiley Periodicals, Inc.</p> </sec> </abstract>