Nutrient recovery from ethanol co-products by a novel mycoalgae biofilm: attached cultures of symbiotic fungi and algae

BACKGROUNDFungal and algae treatment of food-industry waste opens a new avenue for valorizing waste to valuable products through the production of desirable cell biomass. A novel mycoalgae biofilm (symbiotic growth of algae and fungi) was developed in ethanol co-products, the profuse remains from the ethanol distillation process. RESULTSThe mycoalgae biofilm flasks produced more biomass compared with pure fungal cultures under all the conditions tested. The total microbial biomass concentration in mycoalgae biofilm increased from 5.998 g L-1 at 4 d (98.81% fungal biomass and 1.19% algae biomass) to 9.358 g L-1 at 12 d (97.2% fungal biomass and 2.8% algae biomass) with a drop in attached residual solids from 6.304 g L-1 at 4 d to 3.349 g L-1 at 12 d in 10x condensed distillers solubles medium. The high nutrient concentration of P (818 mg L-1) and N (924 mg L-1) in the samples was recovered in the attached mycoalgae biomass at 55.7% and 74%, respectively, with a reduction in COD of up to 65.6%. CONCLUSIONThe results show that ethanol co-products support excellent mycoalgae biofilm growth. The nutrients in ethanol co-products can be efficiently recovered and recycled for agricultural applications and better nutrient management. (c) 2016 Society of Chemical Industry