Biomass of Euglena gracilis Produced in Mineral Medium Supplemented with Craft Brewery Residue

Abstract

Industrial waste from craft breweries can be used to grow microorganisms due to its high nutrient content. Reusing waste and reducing its improper disposal are great economic and environmental strategies. Thus, the objective was to cultivate Euglena sp. in benchtop 1-L photobioreactors using different concentrations of NPK-enriched (0.5-6.0 g L − 1 ) mineral medium with and without the supplementation with a mixture of brewing residues (BR-Mix) with increase of scale (30 L) and BR-Mix supplementation (30% v:v). Carbohydrates, lipids, proteins, fatty acids, and antioxidant potential) were analyzed. The BR-Mix-supplemented medium (0.5 g L − 1 NPK) yielded 15.3 ± 1.4% lipids, 35.1 ± 0.1% proteins, 9.07 ± 0.001% carbohydrates, and 61.3% polyunsaturated totty acids. The antioxidant potential was 170.9 ± 26.3 µmol eq g − 1 of Trolox. Supplementing with 25% BR-Mix resulted in a different biomass composition compared to control (without supplementation): increasing the content of carbohydrates (38.5%), paramylon (91%), and lipids (17.38%), and reducing proteins (26,6%) and antioxidant potential (41,8 µmol eq g − 1 ). Statement of noveltyThe clean industrial residues collected from craft breweries present an opportunity for cultivating microorganisms, in special Euglena sp., an interesting microalgal biomass. This potential not only addresses waste management issues but also contributes to economic and environmental sustainability by reducing improper disposal. We examined the in uence of the brewery waste mixture on enhancing the Euglena sp. growth potential. The subsequent phase of our study involved scaling up the process to a 30 L photobioreactor. Throughout our investigation, we analyzed parameters such as carbohydrates, lipids, proteins, and antioxidant potential under these conditions with a mineral medium and brewery waste.