Quantitative Analysis of Lactobionic Acid in Bioreactor Cultures and Selected Biological Activities

The aim of this study was to quantitatively analyse lactobionic acid obtained from bioreactor cultures using whey as a liquid medium with bacteria of the <i>Pseudomonas taetrolens</i> species. The most important culture parameters affecting the production of the acid are indicated and evaluated. The highest lactobionic acid yield was 37.42 g/L, selecting the appropriate strain (<i>Pseudomonas taetrolens</i> 4') and environmental conditions (2% lactose concentration in the bioreactor). The amount of lactose and lactobionic acid was determined by high-performance liquid chromatography. Microorganism analysis was also carried out using a flow cytometer with imaging to study the metabolic activity of microorganisms during lactobionic acid production. In addition, during the study, Bifidobacteria were microencapsulated with lactobionic acid and their survival was evaluated in an in vitro model of the gastrointestinal tract, checking the prebiotic properties of the acid. The highest number of viable cells in the microcapsules after digestion was obtained using the <i>Bifidobacterium bifidum</i> strain DSM 20082. The antagonistic activity of lactobionic acid was also analysed.