(83c) Biochemical Engineering Characterisation of a Shaken Micro-Photobioreactor Platform for High-Throughput Development of Microalgae Cultivation Processes

Micro-scale technologies for early prediction of key bioprocess parameters and scale-up have previously been applied to biopharmaceutical production and production of human cells for therapy. However, their application to sustainable, bio-renewable energy bioprocess development is only now being considered. Here we describe a shaken micro photo-bioreactor platform that provides the required biochemical engineering conditions suitable for optimisation of microalgae cultivation conditions. Cells are cultured in up to 24 parallel wells with working volumes in the range of 3-4 mL. Illumination was provided via a shaking platform equipped with high powered LEDs with adjustable light intensity and the ability to simulate day-night cycles.

Characterization of a biochemical engineering environment in the shaken photoincubator shows 70 % relative humidity as appropriate conditions for evaporation and condensation control. Light intensity variation across the platforms was in the range of ± 20 µmol.m^-2s^-1., with CO₂ gas transfer rate found to be approximately 33.66 ± 3.0 h^-1 in the photo-incubator.

However, impact of the engineering conditions (160µmol.m^-2s^-1 and 300 rpm shaking speed) showed biomass concentration of 5.87g.L^-1 for Chlorella sorokiniana with high fatty methyl esters acid required for bioenergy production. In the absence of light, microbial fermentation using, E. coli (hydrocarbon producing) was found to be 3.29g/L dry cell weight over cultivation time. In general, the results match with reported literature data.

Adoption of the new micro-scale shaken photobioeactor platform will enable rapid and parallel evaluation of multiple strains of microalgae for their green fuel production capabilities. Along with studies for optimisation of culture conditions this will help reduce bioprocess development costs and timescales.