Cheese whey, produced from coagulation of milk during cheese manufacture, is a major environmental pollutant. The most abundant component in cheese whey is lactose, which is a potential resource for various value-added chemicals. Here, a two-step bioprocess using Saccharomyces cerevisiae and Gluconobacter oxydans to bioconvert cheese whey into ethanol and galactonic acid was first proposed. First, the lactose in cheese whey powder was pretreated with β-galactosidase to obtain glucose and galactose. Subsequently, the glucose was selectively fermented to ethanol by S. cerevisiae to enable G. oxydans-mediated biooxidation of galactose to galactonic acid. Finally, approximately 110 g ethanol, 320 g galactonate, and 150 g mixed protein (residual cheese whey protein and cell protein) was produced from 1 kg CWP. These results are suggestive of alternative methods for management of cheese whey, which may reduce its impact on the environment and result in production of value-added biochemicals.

奶酪制造过程中牛奶凝结产生的奶酪乳清是一种主要的环境污染物。奶酪乳清中最丰富的成分是乳糖，它是各种增值化学品的潜在资源。在此，首先提出了使用酿酒酵母和氧化葡糖杆菌将干酪乳清生物转化为乙醇和半乳糖酸的两步生物过程。首先，用β-半乳糖苷酶预处理干酪乳清粉中的乳糖，以获得葡萄糖和半乳糖。随后，通过酿酒酵母选择性地将葡萄糖发酵为乙醇，从而使氧化丹参菌成为可能。介导的半乳糖生物氧化为半乳糖酸。最后，从1千克CWP中生产出约110克乙醇，320克半乳糖酸酯和150克混合蛋白（残留的干酪乳清蛋白和细胞蛋白）。这些结果表明，可以采用其他方法来处理干酪乳清，这可以减少其对环境的影响并产生增值的生物化学物质。