A framework for accelerated phototrophic bioprocess development: integration of parallelized microscale cultivation, laboratory automation and Kriging-assisted experimental design.
BACKGROUND
Even though microalgae-derived biodiesel has regained interest within the last decade, industrial production is still challenging for economic reasons. Besides reactor design, as well as value chain and strain engineering, laborious and slow early-stage parameter optimization represents a major drawback.


RESULTS
The present study introduces a framework for the accelerated development of phototrophic bioprocesses. A state-of-the-art micro-photobioreactor supported by a liquid-handling robot for automated medium preparation and product quantification was used. To take full advantage of the technology's experimental capacity, Kriging-assisted experimental design was integrated to enable highly efficient execution of screening applications. The resulting platform was used for medium optimization of a lipid production process usingChlorella vulgaristoward maximum volumetric productivity. Within only four experimental rounds, lipid production was increased approximately threefold to 212 ± 11 mg L-1d-1. Besides nitrogen availability as a key parameter, magnesium, calcium and various trace elements were shown to be of crucial importance. Here, synergistic multi-parameter interactions as revealed by the experimental design introduced significant further optimization potential.


CONCLUSIONS
The integration of parallelized microscale cultivation, laboratory automation and Kriging-assisted experimental design proved to be a fruitful tool for the accelerated development of phototrophic bioprocesses. By means of the proposed technology, the targeted optimization task was conducted in a very timely and material-efficient manner.
Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences, IBG-1: Biotechnology, Wilhelm-Johnen-Straße, 52428 Jülich, Germany.
Holger
H
Morschett
Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences, IBG-1: Biotechnology, Wilhelm-Johnen-Straße, 52428 Jülich, Germany.
Lars
L
Freier
Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences, IBG-1: Biotechnology, Wilhelm-Johnen-Straße, 52428 Jülich, Germany.
Jannis
J
Rohde
Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences, IBG-1: Biotechnology, Wilhelm-Johnen-Straße, 52428 Jülich, Germany.
Wolfgang
W
Wiechert
Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences, IBG-1: Biotechnology, Wilhelm-Johnen-Straße, 52428 Jülich, Germany.
Eric
E
von Lieres
Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences, IBG-1: Biotechnology, Wilhelm-Johnen-Straße, 52428 Jülich, Germany.|Institute of Biotechnology, RWTH Aachen University, Aachen, Germany.
Marco
M
Oldiges
Biodiesel; Chlorella vulgaris; Design of experiments; Kriging; Lipid production