Dextrans of Weissella cibaria DSM14295: Microbial production, structure and functionality

Lactic acid bacteria of the genus Weissella contribute to spontaneous fermentation in, e.g., sourdough or sauerkraut, but are not registered as starter cultures because of their pending safety assessment. Some strains are able to produce high amounts of exopolysaccharides. This study aims to demonstrate the techno-functionality of five dextrans from W. cibaria DSM14295, produced under varying cultivation conditions, with respect to structural and macromolecular properties. A maximum of 23.1 g/L dextran was achieved by applying the cold shift temperature regime. The dextrans differed in molecular mass (9-22 & BULL;108 Da, determined by HPSEC-RI/ MALLS), intrinsic viscosity (52-73 mL/g), degree of branching (3.8-5.7 % at position O3, determined by methylation analysis) and their side chain length and architecture, determined by HPAEC-PAD after enzymatic hydrolysis. Stiffness of acid gels from milk spiked with these dextrans increased linearly with dextran concentration. Principal component analysis showed that dextrans produced in a semi-defined medium are primarily described by moisture sorption and branching properties, whereas dextrans produced in whey permeate were similar because of their functional and macromolecular properties. Overall, dextrans from W. cibaria DSM14295 have a high potential because of the high production yield and their functionality which can be tailored by the conditions during fermentation.

Automated summary

The study focuses on the techno-functionality of five dextrans from W. cibaria DSM14295, which were produced under different cultivation conditions. The dextrans differ in molecular mass, intrinsic viscosity, degree of branching, side chain length, and architecture. The stiffness of acid gels spiked with these dextrans increased linearly with dextran concentration. Dextrans from W. cibaria DSM14295 have a high potential due to their high production yield and ability to be tailored by fermentation conditions.