Lactose, a by-product of dairy processing, is the weak link of the modern dairy industry. All other outputs of dairy processing – cream, skim milk, cheese and protein concentrates – sell into markets that are consistently profitable. In contrast, the lactose by-product referred to as ultrafiltration (UF) permeate, is a low value commodity and in many cases lactose streams are disposed of in lagoons or land spread. The goal of this project is to deliver yeast with an engineered pathway that produce fumaric acid through the fermentation of the lactose. This project is using genomics to develop a technology that converts a low value intermediate dairy by-product that is in surplus into a high value product used in the food industry and industrial applications. This will reduce the environmental impact of lactose disposal. Agropur, the receptor on this project, is a Canadian dairy-processing cooperative owned by 3,024 dairy farmers across Canada and is well positioned to implement the resulting technology.