Sustainable algae processing by real-time analysis of its products

Algae bioprocessing is widely seen as a sustainable strategy aligned with UN Development Goals, COP23 and many other world forums on climate change and sustainability. Algae are biocatalysts, biomass raw materials and microbial
factories commercially exploited to produce biooil, food and health care molecules, like omega 3, to cite a few. EPA and DHA are essential omega 3 fatty acids being part of a multimillion pounds nutritional industry. Currently, most omega 3 are extracted from oily fish. However, fish farming is seen as unsustainable and thus manufacturers are turning to microalgae for omega 3 production from light and nutrients. Microalgae bioprocessing is relatively easy but still has drawbacks like manual monitoring, variability of omega 3 content between batches and more. Successful production of desirable amounts and quality of omega 3 is only assessed at the end of experiments or trials, after a great deal of time, cost and effort. Thus, at industrial scale, real-time automatic monitoring of omega 3 production inside microalgae along time is desirable, and it would propel algae bioprocessing into a new XXI century biotechnology. Recent studies provide hopes on how to overcome such limitation. However, approaches to select real-time monitoring strategies for industrial omega 3 production in microalgae remains far from clear. In this work, clarity is provided through a scouting technicoeconomic assessment, with emphasis on EPA. Several analytical techniques used in real-time monitoring of microalgae metabolites and similar fatty cells were compared. For instance, Fourier-transform infrared spectroscopy, nuclear magnetic resonance, cell cytometry, mass spectrometry, differential scanning calorimetry and fluorescence
spectroscopy. Seven analytical techniques have been compared with Raman spectroscopy chosen as the most viable option to monitor omega-3 production in micro-algae. This preliminary information could one day enable 1) the selection of the most appropriate strategy for real-time monitoring of industrial omega 3 production in microalgae, 2) pioneering studies on automatic control, digitalization of microalgae bioprocessing, 3) process integration and 4) sustainable manufacturing of omega 3 with a more environmentally friendly alternative to fish-derived omega 3 in a circular bioeconomy with net zero carbon emissions.