IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
Biotechnol Adv. 2010 May-Jun;28(3):375-84. doi: 10.1016/j.biotechadv.2010.02.002. Epub 2010 Feb 11.
Cheese whey, the main dairy by-product, is increasingly recognized as a source of many bioactive valuable compounds. Nevertheless, the most abundant component in whey is lactose (ca. 5% w/v), which represents a significant environmental problem. Due to the large lactose surplus generated, its conversion to bio-ethanol has long been considered as a possible solution for whey bioremediation. In this review, fermentation of lactose to ethanol is discussed, focusing on wild lactose-fermenting yeasts, particularly Kluyveromyces marxianus, and recombinant Saccharomyces cerevisiae strains. The early efforts in the screening and characterization of the fermentation properties of wild lactose-consuming yeasts are reviewed. Furthermore, emphasis is given on the latter advances in engineering S. cerevisiae strains for efficient whey-to-ethanol bioprocesses. Examples of industrial implementation are briefly discussed, illustrating the viability of whey-to-ethanol systems. Current developments on strain engineering together with the growing market for biofuels will likely boost the industrial interest in such processes.
乳清是主要的乳制品副产物，越来越被认为是许多具有生物活性的有价值化合物的来源。然而，乳清中含量最丰富的成分是乳糖（约 5% w/v），这是一个重大的环境问题。由于产生了大量的乳糖过剩，将其转化为生物乙醇长期以来被认为是乳清生物修复的一种可行方法。在本文综述中，讨论了将乳糖发酵为乙醇的问题，重点介绍了野生乳糖发酵酵母，特别是马克斯克鲁维酵母和重组酿酒酵母菌株。综述了早期筛选和鉴定野生乳糖消耗酵母发酵特性的工作。此外，还重点介绍了用于高效乳清到乙醇生物过程的工程酿酒酵母菌株的最新进展。简要讨论了工业实施的例子，说明了乳清到乙醇系统的可行性。随着生物燃料市场的不断增长，目前在菌株工程方面的发展可能会提高人们对这类工艺的工业兴趣。
