Exopolysaccharides production by Lactiplantibacillus plantarum strains isolated from industrial rye bread sourdoughs : [presentation]
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Kuupäev
2026
Kättesaadavus
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Estonian University of Life Sciences
Abstrakt
Exopolysaccharides (EPS) are high-molecular-weight polysaccharides synthesized by microorganisms, including lactic acid bacteria (LAB), and are recognized for their impact on both technological and functional attributes of fermented foods. EPS contribute to improved texture, viscosity, water retention, and emulsion stability, while reducing syneresis, and may also exert bioactive effects such as antioxidant, immunomodulatory, anti-cancer, and modulatory activities on gastrointestinal and lipid metabolism. Within LAB, Lactiplantibacillus plantarum is of particular interest owing to its ability to produce EPS with both technological and functional significance. In sourdoughs, preserving microbial diversity in traditional starters is crucial, as these ecosystems harbor unique LAB strains with functional traits that are increasingly lost to uniform commercial cultures. The aim of this study was to characterize the EPS-producing capacity of L. plantarum strains isolated from decades-old, continuously propagated rye sourdoughs and to compare them with a commercial reference strain, thereby assessing their potential as technologically and functionally valuable starter culture candidates. A total of ten strains from an Estonian industrial sourdough, along with one commercial strain, L. plantarum TAK59 (Nordwise Biotech OÜ, Estonia), were included. EPS production by the strains was evaluated after cultivation in MRS broth with 2% sucrose, followed by isolation and quantification using gravimetric and phenol–sulfuric acid assays. The EPS produced exhibited glucose-equivalent sugar contents ranging from 278.3 to 362.8 µg/mg and yields of 131.4–225.2 mg/L. The highest sugar content was observed in L. plantarum strain A44, whereas the greatest EPS yield was recorded for strain A37. The commercial strain TAK59 yielded the lowest EPS dry mass and productivity. No statistically significant differences were detected in sugar content or yield among individual strains or between genotypes (p > 0.05). Notably, differences were observed in the dry mass of lyophilized EPS. L. plantarum isolates A52 and A45, belonging to genotype G5, displayed significantly lower dry mass compared to other genotypes (p < 0.05), except for G6 (L. plantarum isolates A51 and A44), for which differences were not statistically significant. Similarly, no linear correlation was observed between sugar content and dry matter (R²=0.0177), suggesting that these two quantification methods are not directly comparable and likely capture different characteristics of the EPSs, such as purity, composition, or structural variability of the polysaccharides. In conclusion, all L. plantarum strains assessed in this study demonstrated substantial EPS-producing capacity. The results contribute to valorizing sourdough biodiversity and support the development of tailored starter cultures for enhancing bread quality and functional potential. The long-term propagation of these sourdoughs has likely driven strain-specific adaptations, making them valuable sources of technologically and functionally distinct EPS producers compared to commercial starters. Future research should focus on optimizing cultivation conditions (medium composition, pH, temperature, incubation time, nutrient availability) to maximize EPS yield and enable targeted applications in improving the texture, stability, and functionality of fermented foods.
Kirjeldus
Märksõnad
sourdough, lactic acid bacteria, exopolysaccharide, phenol-sulfuric acid method, presentations
Viide
Lutter, L., Pikkel, N., Ben Othman, S. & Andreson, H. (2026). Exopolysaccharides production by Lactiplantibacillus plantarum strains isolated from industrial rye bread sourdoughs : [presentation]. Estonian University of Life Sciences. http://hdl.handle.net/10492/10334