Fermentation of lactose to bio-ethanol by yeasts as part of integrated solution...

• Author(s): Guimarães, Pedro M. R. ; Teixeira, J. A. ; Domingues, Lucília
• Date: 2010
• Persistent ID: http://hdl.handle.net/1822/10543
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Lactose fermentation; Cheese whey; Bio-ethanol; Yeast; Kluyveromyces; Recombinant S. cerevisiae
• Document Type: Article
• Language: English

Description

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.