Potato and dairy industry side streams as feedstock for fungal and plant cell cultures

Utilization of industrial side streams as nutrient source for cellular agriculture is a promising option to improve the sustainability of the production processes. The aim of the study was to evaluate usability of two liquid food industry side streams, potato cell fluid and acid whey, as nutrient source for production of food ingredients with plant cell cultures (arctic bramble ( Rubus arcticus L.) and tobacco BY-2 ( Nicotiana tabacum L.)) and filamentous fungi ( Paecilomyces variotii , Rhizopus oligosporus and Trichoderma reesei ). The side streams were found to contain various sugars and other potential nutrients suitable for the studied organisms. The side streams were used as a sole nutrient source (fungi) or as a replacement of selected nutrients in the growth media (fungi and plant cells) in flask scale cultivations. Acid whey was successfully used as a growth medium for filamentous fungi, but it inhibited plant cell growth presumably due to high organic acid content (14 g/l). Potato side stream was found suitable as a fungal and plant cell growth media supplement, and it was used together with glucose for filamentous fungi, or as a partial replacer of macronutrients for plant cells, in bioreactor cultivations yielding high fungal (up to 36 g/l dry weight) and good plant cell (9.5 g/l dry weight) biomass production. Analyses of the produced biomasses revealed good nutritional value in terms of amino acid (17–27 % of dry matter) and dietary fiber (23–30 % of dry matter) contents, giving good premises for utilization in human nutrition. • Food industry side stream have upcycling potential back to food production. • Fungal and plant cell biomasses were produced with side stream supplemented media. • Potato cell fluid contained valuable nutrients to be used for growth media. • Acid whey sustained fungal growth but inhibited plant cell growth. • Fungal and plant cell biomasses are high in essential amino acids and dietary fibre.