Department of Agricultural and Biological Engineering, Pennsylvania State University, University Park, PA, 16802, USA.
Department of Food Engineering, Middle East Technical University, 06800, Ankara, Turkey.
Appl Microbiol Biotechnol. 2020 Jul;104(14):6115-6128. doi: 10.1007/s00253-020-10682-0. Epub 2020 May 21.
Distillers' dried grain with solubles (DDGS) is a byproduct of bioethanol fermentation, which uses the dry milling technology for starch-rich grains such as corn, wheat, and barley. The current interest in bioethanol is increasing due to the need for renewable liquid fuels specifically in the transportation sector. Since DDGS is rich in crude protein, fat, fiber, vitamins, and minerals, it is currently used as aquaculture, livestock, and poultry feeds. In recent years, DDGS has been used as feedstock in the production of value-added products via microbial fermentation. Numerous studies reported the production organic acids, methane, biohydrogen, and hydrolytic enzymes using DDGS. While DDGS contains remarkable amounts of macronutrients, pre-treatment of DDGS is required for release of the fermentable sugars. The pre-treatment methods such as chemical, physical, and biological origin are either solely used or combined to obtain maximal yields for different applications. Therefore, this review summarizes some of the most prominent pre-treatment processes generating high fermentable sugar yields for the productions of value-added products in the last 5 years. A special focus has been given to the effect of the variability of DDGS on the final product. Integration of hydrolytic enzyme production with the traditional bioethanol production facilities has been discussed for further improvement of bioethanol, methane, and biohydrogen using DDGS as fermentation feedstock.Key points• Distillers' dried grain with solubles (DDGS) has high nutritional value, but the nutritional profile is variable.• DDGS can be used for microbial fermentation feedstock to produce value-added products.• A review of the microbial products using DDGS is given for the last 5 years.• DDGS has the potential to replace expensive feedstocks of value-added products.
酒糟及其可溶物（DDGS）是生物乙醇发酵的副产品，该技术采用干法对富含淀粉的谷物（如玉米、小麦和大麦）进行加工。由于对可再生液体燃料的需求，特别是在交通运输领域，生物乙醇的应用日益广泛。由于 DDGS 富含粗蛋白、脂肪、纤维、维生素和矿物质，因此目前被用作水产养殖、家畜和家禽的饲料。近年来，DDGS 已被用于通过微生物发酵生产增值产品的原料。许多研究报告称，利用 DDGS 生产有机酸、甲烷、生物氢和水解酶。虽然 DDGS 含有大量的宏量营养素，但需要对 DDGS 进行预处理才能释放出可发酵的糖。预处理方法有化学法、物理法和生物法等，这些方法单独使用或结合使用，以获得不同应用的最大产量。因此，本综述总结了过去 5 年来一些最显著的预处理方法，这些方法可产生高产量的可发酵糖，用于生产增值产品。特别关注了 DDGS 的可变性对最终产品的影响。还讨论了将水解酶生产与传统生物乙醇生产设施相结合，以利用 DDGS 作为发酵原料进一步提高生物乙醇、甲烷和生物氢的产量。关键点• 酒糟及其可溶物（DDGS）具有很高的营养价值，但营养成分具有可变性。• DDGS 可用于微生物发酵原料生产增值产品。• 综述了过去 5 年来利用 DDGS 生产微生物产品的情况。• DDGS 有可能替代高附加值产品的昂贵原料。
