Molecular characterization of exopolysaccharide from Periweissella beninensis LMG 25373T and technological properties in plant-based food production

Periweissella beninensis LMG 25373T, belonging to the recently established Periweissella genus, exhibits unique motility and high adhesion capabilities, indicating significant probiotic potential, including resilience under simulated gastrointestinal conditions. This study demonstrates for the first time that P. beninensis LMG 25373<^>T produces a dextran-type exopolysaccharide (EPS) with a distinctive high degree of branching (approximately 71 % of alpha-(1-* 6)-linkages and 29 % alpha-(1-* 3)-linkages). Growth performance, acidification, and proteolytic activity were investigated in various plant-based substrates (lentil, chickpea, and rice flours water soluble extracts and semi-liquid mixtures), in comparison with the well-characterized lactic acid bacteria strains Leuconostoc pseudomesenteroides DSM 20193 (EPS-producing) and Lacticaseibacillus rhamnosus GG (probiotic). The strain displayed effective pro-technological properties, especially in gelatinized and non-gelatinized legume-based substrates, achieving EPS synthesis levels of up to 1.3 g/100 g and 2.7 +/- 0.2 g/100 g, respectively. When used as a starter for a plant-based yogurt-type ("gurt") prototype, compared to the control, P. beninensis LMG 25373T produced a substantial increase in viscosity which remained stable during refrigerated storage, confirming the role of its unique structure pattern as a hydrocolloid. Furthermore, the strain demonstrated high viability throughout storage, an essential trait for probiotic food applications.