Recycling of food waste as nutrients in Chlorella vulgaris cultivation

Heterotrophic cultivation of Chlorella vulgaris was investigated in food waste hydrolysate. The highest exponential growth rate in terms of biomass of 0.8 day−1 was obtained in a hydrolysate consisting of 17.9 g L−1 glucose, 0.1 g L−1 free amino nitrogen, 0.3 g L−1 phosphate and 4.8 mg L−1 nitrate, while the growth rate was reduced in higher concentrated hydrolysates. C. vulgaris utilized the nutrients recovered from food waste for the formation of biomass and 0.9 g biomass was produced per gram glucose consumed. The microalgal biomass produced in nutrient sufficient batch cultures consisted of around 400 mg g−1 carbohydrates, 200 mg g−1 proteins and 200 mg g−1 lipids. The conversion of nutrients derived from food waste and the balanced biomass composition make C. vulgaris a promising strain for the recycling of food waste in food, feed and fuel productions.