Department of Microbiology, Federal University of Viçosa, Viçosa, Brazil.
Agricultural Sciences Institute, Federal University of Minas Gerais, Montes Claros, Brazil.
Environ Technol. 2020 Oct;41(24):3210-3218. doi: 10.1080/09593330.2019.1604813. Epub 2019 Apr 14.
Cheese whey is a dairy industry by-product responsible for serious environmental problems. Its fermentation would allow reducing its environmental impact and producing, at the same time, high-value products, hence ensuring cleaner production. Batch fermentations of cheese whey permeate, either as such or 1.5-fold or twice-concentrated, by CBS2359 were performed in flasks with or without agitation to select the best conditions to produce simultaneously ethanol and biomass with high -galactosidase activity. In shake cultures, the highest ethanol concentration (15.0 g L), yield on consumed lactose (0.47 g g) and productivity (0.31 g L h), were obtained on cheese whey permeate as such, corresponding to 87.4% fermentation efficiency, but -galactosidase activity was disappointing (449.3-680.0 U g). In static cultures on twice-concentrated whey permeate, despite a decrease in fermentation efficiency and yield, ethanol production increased by 48% and -galactosidase activity by no less than 209-367%. Therefore, cheese whey should be considered an alternative feedstock rather than an undesirable dairy industry by-product.
乳清是乳制品工业的副产物，会造成严重的环境问题。发酵乳清可以减少其环境影响，并同时生产高价值的产品，从而确保清洁生产。使用 CBS2359 对乳清进行分批发酵，无论是未经浓缩的乳清还是 1.5 倍或 2 倍浓缩的乳清，在有搅拌或无搅拌的摇瓶中进行，以选择最佳条件来同时生产具有高β-半乳糖苷酶活性的乙醇和生物质。在摇瓶培养中，在未经浓缩的乳清中可获得最高的乙醇浓度（15.0 g/L）、消耗乳糖的产率（0.47 g/g）和生产率（0.31 g/L/h），对应的发酵效率为 87.4%，但β-半乳糖苷酶活性令人失望（449.3-680.0 U/g）。在两倍浓缩乳清的静态培养中，尽管发酵效率和产率下降，但乙醇产量增加了 48%，β-半乳糖苷酶活性增加了不少于 209-367%。因此，乳清应被视为一种替代原料，而不是乳制品工业的不良副产物。
