Biotechnology for the Valorization of Dairy Industry By-Products: the Case of the Lactobionic Acid

Biotechnology production of LactoBionic Acid (LBA) from Ricotta Cheese Whey (RCW) was investigated in order to valorize dairy industry promising by-product. Fermentations in 3L-StirredTankReactors, in batch conditions, allowed to reach production yields of 34.25 ± 2.86 g / L and 30.18 ± 0.3 g / L for LBA for two strains of Pseudomonas taetrolens (LMG2336 and DSM21104 respectively) with conversion yields around 85%, after 48 hours. Furthermore fed-batch configurations have allowed to reach values of about 60 g / L of ALB, providing interesting perspectives for the development of a continuous process. It was also evaluated the possibility to use matrices obtained following procedures of ultrafiltration and nanofiltration of the RCW, aimed at the separation of proteins and bioactive peptides, obtaining similar results, but promising in view of the setup of a concept point of integrated biorefinery for the development of the dairy industry by-products. Finally a preliminary approach to the downstream recovery and purifies LBA produced by the fermentation process, using ceramic membranes (suitable for food applications) in different pH conditions has allowed us to achieve a 32% recovery at pH 9. Even this, it is very promising in view of a continuous process of production and purification of LBA in order to cut cost