Physicochemical and structural characterisation of a branched dextran type exopolysaccharide (EPS) from Weissella confusa S6 isolated from fermented sausage (Sucuk)

Fatma Beyza Özpınar, Hümeyra İspirli, Selma Kayacan, Kader Korkmaz, Sevda Dere, Osman Sagdic, Zuhal Alkay, Yunus Emre Tunçil, Mutamed Ayyash, Enes Dertli

    Research output: Contribution to journalArticlepeer-review

    Abstract

    Exopolysaccharide (EPS) producing Lactic Acid Bacteria (LAB) species can be presented in distinct environments. In this study, Turkish fermented sausage (sucuk) was tested for the presence of EPS producer LAB strains and slimy-mucoid colonies were selected for further tests. Among the isolates, Weissella confusa strain S6 was identified and tested for the physicochemical characterisation of its EPS. This strain was found to produce 0.74 g L−1 of EPS in modified BHI medium conditions. Structural characterisation of EPS S6 by 1H and 13C NMR demonstrated that EPS S6 was a highly branched dextran type glucan formed by mainly (1 → 2)-linked α-D-glucose units together with low levels of (1 → 3)-linked α-D-glucose units as branching points. This structure was further confirmed by methylation analysis detected by GC–MS. An average molecular weight of 8 × 106 Da was detected for dextran S6. The FTIR analysis supported the dextran structure and revealed the presence of distinct functional groups within dextran S6 structure. A strong thermal profile was observed for dextran S6 detected by DSC and TGA analysis and dextran S6 revealed a degradation temperature of 289 °C. In terms of physical status, dextran S6 showed amorphous nature detected by XRD analysis. SEM analysis of dextran S6 demonstrated its rough, compact and porous morphology whereas AFM analysis of dextran S6 detected in its water solution showed the irregularity with no clear cross-link within the dextran chains. These technological features of dextran S6 suggests its potential to be used for in situ or ex situ application during meat fermentations.

    Original languageEnglish
    Article number130507
    JournalInternational Journal of Biological Macromolecules
    Volume264
    DOIs
    Publication statusPublished - Apr 2024

    Keywords

    • Dextran
    • Exopolysaccharides (EPS)
    • Fermented sausage
    • Physicochemical characterisation
    • Weissella confusa

    ASJC Scopus subject areas

    • Structural Biology
    • Biochemistry
    • Molecular Biology

    Fingerprint

    Dive into the research topics of 'Physicochemical and structural characterisation of a branched dextran type exopolysaccharide (EPS) from Weissella confusa S6 isolated from fermented sausage (Sucuk)'. Together they form a unique fingerprint.

    Cite this