Utilization of food waste-derived volatile fatty acids for production of edible Rhizopus oligosporus fungal biomass

• Published in: Bioresource technology Vol. 310; p. 123444
• Main Authors: Wainaina, Steven, Kisworini, Afrilia Dwi, Fanani, Marizal, Wikandari, Rachma, Millati, Ria, Niklasson, Claes, Taherzadeh, Mohammad J.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2020
• Subjects: Anaerobic digestion; Anaerobiosis; Biomass; Bioreactors; Edible filamentous fungal biomass; Fatty Acids, Volatile; Fed-batch cultivation; Food; Food waste; Refuse Disposal; Resource Recovery; Resursåtervinning; Rhizopus; Rhizopus oligosporus; Volatile fatty acids; Food waste; Rhizopus oligosporus; Fed-batch cultivation; Volatile fatty acids; Edible filamentous fungal biomass; Anaerobic digestion
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2020.123444

[Display omitted] •Rhizopus oligosporus was grown solely on food waste-derived VFAs.•Four-fold biomass increase observed in fed-batch compared to batch cultivation.•Of the consumed carboxylates, acetic acid was the most preferred.•Maximum biomass yield of 0.21 ± 0.01 g dry biomass/g VFAs COD eq. consumed obtained.•Highest protein content in the biomass reached 39.28 ± 1.54%. Rhizopus oligosporus is an edible filamentous fungus that can contribute to meet the growing demand for single-cell protein. Volatile fatty acids (VFAs) are favorable potential substrates for producing R. oligosporus biomass due to their capacity to be synthesized from a wide range of low-value organic solid wastes via anaerobic digestion. The goal of this work was to cultivate R. oligosporus using food waste-derived VFAs as the sole carbon source. To maintain the requisite low substrate concentrations, the fed-batch cultivation technique was applied. This resulted in a four-fold improvement in biomass production relative to standard batch cultivation. Maximum biomass yield of 0.21 ± 0.01 g dry biomass/g VFAs COD eq. consumed, containing 39.28 ± 1.54% crude protein, was obtained. In the bubble-column bioreactors, the complete uptake of acetic acid was observed, while the consumptions of caproic and butyric acids reached up to 97.64% and 26.13%, respectively.