Efficient lactobionic acid production from whey by Pseudomonas taetrolens under pH-shift conditions

► Production of lactobionic acid from whey by Pseudomonas taetrolens. ► Enhancement in terms of bioconversion yield was achieved by varying inoculum size. ► Bioconversion efficiency was highly depended on inoculum age. ► A pH-shift cultivation strategy has enabled complete lactose bioconversion. ► Growth phase was featured by broth alkalinization and decrease in dissolved oxygen.