(558a) Conversion of Cheese Whey to Lactobionic Acid

Lactobionic acid (LBA) is a versatile, high-value, low-volume chemical with numerous applications in the food, pharmaceutical, cosmetic, and chemical industries. Microbial production of LBA has the advantages of high selectivity and the ability to use cheese whey, a waste stream from the dairy industry, which is rich in lactose. However, microbial LBA production has not yet been developed as successfully as other organic acids, despite attempts being made to use wild type bacteria, fungi and yeast strains. There is no commercial implementation of microbial LBA production technologies due to the following factors: 1) The most robust strains are pathogenic, which prevents their industrial implementation. 2) The enzyme (cellobiose dehydrogenase or lactose dehydrogenase) which oxidizes lactose to LBA is produced only in the stationary phase. The highest level production of LBA was only achievable under resting cell conditions, which are not usually used in industrial fermentations. 3) The microorganism consumed LBA at the later stage of the fermentation. We report engineering a Neurospora crass strain for cellobionic acid production from cheese whey and solving the problems associated with LBA fermentation using metabolic engineering efforts