Use of side streams from algae and cyanobacteria production as a culture medium for Basidiomycota for the production of natural aroma components and mycelia
A research project of the Justus Liebig University Giessen, Institute for Food Chemistry and Biotechnology
Mushrooms, their mycelia and microalgae are promising foods of the future and can help to ensure a sustainable food supply for people. For example, they can be used as a raw material in the production of meat and fish alternatives. They can also generate natural components for the flavoring or coloring of food.
When cultivating fungi or microalgae, particular attention should be paid to making the processes sustainable and resource-efficient so that they can be used sensibly and successfully in the long term. Circular or "zero waste" processes in particular offer clear advantages, as the by-products are recycled and efficiency is therefore particularly high. Based on this goal, the research project investigated whether side streams from microalgae production can be used as a source of nutrients in the cultivation of fungi from the phylum Basidiomycota. It was also evaluated whether growth on these marine sources leads to the generation of valuable flavors.
Microalgae and cyanobacteria as a comprehensive source of nutrients
First, an emersed screening of 33 fungal species was carried out, in which growth was measured over three weeks on agar plates containing culture media with various microalgae and cyanobacteria. The results showed that some fungi grew well on these media, while others were less successful. The sensory evaluation also revealed that some mushroom species produced savory and fishy flavors, especially when cyanobacteria were added to the medium.
Three mushrooms that showed good growth and interesting aromas were then selected to be grown in submerged cultures. The aroma profiles of the submerged cultures showed sweet, fruity and smoky odor impressions, whereby the odor intensities generally remained low.
In summary, this bachelor thesis demonstrated that microalgae and cyanobacteria are generally suitable as components of culture media for the cultivation of Basidiomycota in both emersed and submerged cultures. With regard to savory and meat- and fish-like aromas, it was found that these were perceived in certain species, albeit to a lesser extent.
Further analyses could now investigate, for example, whether the use of extracted marine biomass can also be used and whether the growth conditions can be further optimized in terms of yield and aroma production.
Justus Liebig University Giessen, Institute for Food Chemistry and Biotechnology
Project manager: Dr. Martin Gand