Development of a bioreactor for benthic diatoms


Background and motivation
The cultivation of microalgae is a rather young technology and has so far been carried out especially to obtain food bases for aquaculture (e.g. fish and mussels). Due to their high protein and lipid content as well as their high concentrations of vitamins and polyunsaturated fatty acids, some microalgae are also used as high-quality food supplements or as starting material for pharmaceutical products. So far, however, both the studies and the cultivation have mainly referred to algae living in suspension and are therefore mainly carried out in suspension cultures.
Benthic diatoms living in tidal flats are subject to extremely high variability in their living conditions: They experience extreme fluctuations in temperatures, salinities, nutrient availability and radiation intensities due to the tides and the associated temporary drying out of the tidal flats. Therefore, these microalgae must protect themselves against this high variability by forming special substances. Although these constituents are still little studied, there are indications that they have great potential as source substances for sustainable economic use, including pharmaceutical products and food supplements.


Objectives and approach
The BIOBED (BIOreactor for BEnthic Diatoms) project, which has been running since October 2020, is currently in the exploratory phase.  The goals of the project are, on the one hand, the evaluation of benthic diatoms with regard to their ingredients and cultivation conditions and, on the other hand, the technical planning of a photo-bioreactor facility in which benthic diatoms can also be cultivated on a larger scale.