Biotechnological Applications of Sourdough Lactic Acid Bacteria: A Source for Vitamins Fortification and Exopolysaccharides Improvement

Sourdough fermentation relies on complex microbial ecosystems composed of lactic acid bacteria (LAB) and yeasts. As in other matrices, the fermentative microbiota deeply influences sensory, nutritional, functional, and hygienic quality. In particular, lactic acid bacteria are also an important starting point for developing specific food biotechnological applications. This chapter focuses on the potential exploitation of selected LAB to bio-produce, in situ, B-group vitamins, exopolysaccharides such as dextrans, and prebiotics, with positive modulation of global sourdough features. Concerning these molecular classes, the presented overview encompasses the importance of LAB biodiversity, the study of the genetic basis for the production of LAB metabolites, and the design of biotechnological strategies, reporting selected case studies from the scientific literature. Bread making has been reported as a representative production, but the proposed applications are transferable to other sourdough-based and, more generally, plant-based fermented foods and beverages. The possibility to bio-produce the molecules of interest directly in the matrix is well in line with the needs of sustainable development in food systems.