Repeated fed-batch cultivation of Thermosynechococcus elongatus BP-1 in flat-panel airlift photobioreactors with static mixers for improved light utilization: Influence of nitrate, carbon supply and photobioreactor design

Abstract Microalgae mass cultivation is limited by light availability due to effects of absorption and reflection. These effects can only partially be coped with by increasing the photon-flux density. Further inhibitive effects, especially during outdoor cultivations, are described by photoinhibition and photosaturation. Therefore, moving the cells towards the light source and away from it in a distinct mode by convective mass transfer is the method of choice to cope with these inhibitive effects. Hereby, the utilization of culture-flow directing installations, e.g. static mixers, within photobioreactors can be of great benefit. The thermophilic model organism Thermosynechococcus elongatus BP-1 was cultivated in flat-panel airlift photobioreactors with and without static mixers in order to show their positive influence on growth kinetics. Optimal nitrate and carbon concentrations were 2000 mg L − 1 NO 3 − , 0.04 g L − 1 Na 2 CO 3 combined with 6.3% v/v CO 2 . It was shown that photobioreactors with static mixers increase volumetric productivity by a factor of 3.4 and final biomass concentration by a factor of 2.0. A maximum productivity of 2.9 g DW  L − 1  d − 1 was demonstrated, to the knowledge of the authors the highest to be reported for the cyanobacterium T. elongatus BP-1.

[1]  Poonam Singh,et al.  Trends and novel strategies for enhancing lipid accumulation and quality in microalgae , 2016 .

[2]  U. Schmid-Staiger,et al.  A novel airlift photobioreactor with baffles for improved light utilization through the flashing light effect. , 2001, Journal of biotechnology.

[3]  Colin P.D. Birch,et al.  A New Generalized Logistic Sigmoid Growth Equation Compared with the Richards Growth Equation , 1999 .

[4]  Thomas Hirth,et al.  Optimization of outdoor cultivation in flat panel airlift reactors for lipid production by Chlorella vulgaris , 2013, Biotechnology and bioengineering.

[5]  Teresa M. Mata,et al.  Microalgae for biodiesel production and other applications: A review , 2010 .

[6]  José M. Baptista,et al.  Light requirements in microalgal photobioreactors: an overview of biophotonic aspects , 2010, Applied Microbiology and Biotechnology.

[7]  John G. Day,et al.  Overcoming biological constraints to enable the exploitation of microalgae for biofuels. , 2012, Bioresource technology.

[8]  P. King,et al.  Site Saturation Mutagenesis Demonstrates a Central Role for Cysteine 298 as Proton Donor to the Catalytic Site in CaHydA [FeFe]-Hydrogenase , 2012, PloS one.

[9]  M. Madigan,et al.  Brock Biology of Microorganisms , 1996 .

[10]  Carlos Vílchez,et al.  Horizontal or vertical photobioreactors? How to improve microalgae photosynthetic efficiency. , 2011, Bioresource technology.

[11]  Y. Chisti.  Biodiesel from microalgae. , 2007, Biotechnology advances.

[12]  R W Krauss,et al.  The Effects of Light Intensity on the Growth Rates of Green Algae. , 1958, Plant physiology.

[13]  T. Yamaoka,et al.  Photosynthetic activities of a thermophilic blue-green alga , 1978 .

[14]  Basar Uyar,et al.  Passive temperature control of an outdoor photobioreactor by phase change materials , 2015 .

[15]  I. Ross,et al.  Automated nutrient screening system enables high-throughput optimisation of microalgae production conditions , 2015, Biotechnology for Biofuels.

[16]  Choul-Gyun Lee,et al.  Calculation of light penetration depth in photobioreactors , 1999 .

[17]  E. Sforza,et al.  Adjusted Light and Dark Cycles Can Optimize Photosynthetic Efficiency in Algae Growing in Photobioreactors , 2012, PloS one.

[18]  Extremophiles and Biotechnology , 2009 .

[19]  M. Gorwa-Grauslund,et al.  Adaptation of Scheffersomyces stipitis to hardwood spent sulfite liquor by evolutionary engineering , 2015, Biotechnology for Biofuels.

[20]  M. Ikeuchi,et al.  Complete genome structure of the thermophilic cyanobacterium Thermosynechococcus elongatus BP-1. , 2002, DNA research : an international journal for rapid publication of reports on genes and genomes.

[21]  P. Campbell,et al.  THE INFLUENCE OF pH ON ALGAL CELL MEMBRANE PERMEABILITY AND ITS IMPLICATIONS FOR THE UPTAKE OF LIPOPHILIC METAL COMPLEXES 1 , 2012, Journal of phycology.

[22]  Jun Liang,et al.  Characterization of a novel thermophilic cyanobacterial strain from Taian hot springs in Taiwan for high CO2 mitigation and C-phycocyanin extraction , 2013 .

[23]  R. Sander.  Compilation of Henry's law constants (version 4.0) for water as solvent , 2015 .

[24]  P. Wangikar,et al.  Extremophilic micro-algae and their potential contribution in biotechnology. , 2015, Bioresource technology.

[25]  A. Vonshak,et al.  Photoadaptation, photoinhibition and productivity in the blue‐green alga, Spirulina platensis grown outdoors , 1992 .

[26]  H. Chu,et al.  Effects of dissolved inorganic carbon and nutrient levels on carbon fixation and properties of Thermosynechococcus sp. in a continuous system. , 2012, Chemosphere.

[27]  E. Torres,et al.  Production and analysis of secondary carotenoids in green algae , 2000, Journal of Applied Phycology.

[28]  G Charles Dismukes,et al.  Aquatic phototrophs: efficient alternatives to land-based crops for biofuels. , 2008, Current opinion in biotechnology.

[29]  H. Chu,et al.  Effects of light availability on the biomass production, CO2 fixation, and bioethanol production potential of Thermosynechococcus CL-1. , 2013, Bioresource technology.

[30]  Ulrike Schmid-Staiger,et al.  Optimization of eicosapentaenoic acid production byPhaeodactylum tricornutumin the flat panel airlift (FPA) reactor , 2004, Journal of Applied Phycology.