Development and screening of a sustainable algae fermentation medium

The aim was to investigate the effect of wet oxidation (WO) on anaerobic digested (AD) cow manure and evaluate it as a phototrophic and mixotrophic growth medium for microalgal growth (Chlorella saccharophila). The wet oxidation successfully removed the malodor from the manure, and degraded phenols completely resulting in a clear medium that made phototrophic growth possible. The WO manure supported microalgal growth, and could completely replace defined growth medium with lower toxicity than non-treated manure. At concentrations above 7% WO manure phototrophic growth was heavily inhibited. Heterotrophic growth was inhibited at concentrations above 15% WO manure

Perspectives: WO manure can be used as the only nutrient source, but separation techniques, feeding strategy and addition of other waste streams should be investigated to balance biomass composition and minimise growth inhibition