Upcycling of Whey Permeate through Yeast- and Mold-Driven Fermentations under Anoxic and Oxic Conditions

Abstract

Dairy manufacturing generates whey by-products, many of them considered waste; others, such as whey permeate, a powder high in lactose and minerals from deproteinated whey, have unrealized potential. This study identified yeast species capable of utilizing lactose from whey permeate to produce ethanol or organic acids, and identified fungal species that reduced the acidity of whey by-products. Reconstituted whey permeate was fermented anaerobically or aerobically for 34 days, using species from Cornell University’s Food Safety Lab, Alcaine Research Group, and Omega Labs. Yeast species: Kluyveromyces marxianus, Kluyveromyces lactis, Dekkera anomala, Brettanomyces claussenii, Brettanomyces bruxellensis; mold species: Mucor genevensis and Aureobasidium pullulans. Density, pH, cell concentrations, organic acids, ethanol, and sugar profiles were monitored. Under anoxic conditions, K. marxianus exhibited the greatest lactose utilization and ethanol production (day 20: lactose non-detectable; 4.52% ± 0.02 ethanol). Under oxic conditions, D. anomala produced the most acetic acid (day 34: 9.18 ± 3.38 g/L), and A. pullulans utilized the most lactic acid, increasing the fermentate’s pH (day 34: 0.26 ± 0.21 g/L, pH: 7.91 ± 0.51). This study demonstrates that fermentation of whey could produce value-added alcoholic or organic acid beverages, or increase the pH of acidic by-products, yielding new products and increasing sustainability.

Recent advances in whey processing and valorisation: Technological and environmental perspectives

“…Some examples of these beverages produced by aerobic fermentations include kombucha or kefir which are high in organic acids (acetic and lactic acids). In a recent study, Marcus et al (2021) reported that it was possible to produce new value-added and sustainable organic acid or alcoholic beverages and also to increase the pH of acidic by-products using reconstituted whey permeate using yeast species (Kluyveromyces marxianus, Kluyveromyces lactis, Dekkera anomala, Brettanomyces claussenii, Brettanomyces bruxellensis) and mould species (Mucor genevensis and Aureobasidium pullulans).…”

Determinants of Implementation of the Circular Economy in the Food Processing Sector on the Example of the Dairy Industry

“…Literature on the subject indicates numerous ways of using dairy waste to produce various value-added products. They can be used for the production of functional drinks (Lawton et al, 2021), bioplastics (Tripathi et al, 2021), biochemicals (Asunis et al, 2019), biocatalysts (Bhusari et al, 2021), unicellular proteins (Gour et al, 2017), organic acids (Marcus et al, 2021;Qin et al, 2021), microbial fuel cells (Ahmad et al, 2019), biodiesel (Kavitha et al, 2019), bioenergy (Asunis et al, 2020), ethanol (Zheng et al, 2022, biofuel (Choudhary et al, 2021), biohydrogen (Ayil-Gutiérrez et al, 2021), organic fertilizer (Alharbi et al, 2021).…”

Aerobic Cultivation of Mucor Species Enables the Deacidification of Yogurt Acid Whey and the Production of Fungal Oil

“…Mucor is a fungal genus commonly regarded as a food contaminant. Marcus et al [17] observed that Mucor genevensis slightly increased the pH of whey permeate when it was cultivated in aerobic conditions. This finding provided a promising strategy to deacidify YAW by utilizing the metabolism of M. genevensis, leading to a potential treatment for YAW prior to disposal or other processing methods [17].…”

“…Marcus et al [17] observed that Mucor genevensis slightly increased the pH of whey permeate when it was cultivated in aerobic conditions. This finding provided a promising strategy to deacidify YAW by utilizing the metabolism of M. genevensis, leading to a potential treatment for YAW prior to disposal or other processing methods [17]. Chan et al [18] explored the use of Mucor circinelloides in lactose-hydrolyzed cheese whey permeate to produce a biomass containing more than 20% w/w lipid.…”