Development and Physical Characterization of α-Glucan Nanoparticles

Abstract

α-Glucans that were enzymatically synthesized from sucrose using glucansucrase cloned from Leuconostoc mesenteroides NRRL B-1118 were found to have a glass transition temperature of approximately 80 °C. Using high-pressure homogenization (~70 MPa), the α-glucans were converted into nanoparticles of ~120 nm in diameter with a surface potential of ~−3 mV. Fluorescence measurements using 1,6-diphenyl-1,3,5-hexatriene (DPH) indicate that the α-glucan nanoparticles have a hydrophobic core that remains intact from 10 to 85 °C. α-Glucan nanoparticles were found to be stable for over 220 days and able to form at three pH levels. Accelerated exposure measurements demonstrated that the α-glucan nanoparticles can endure exposure to elevated temperatures up to 60 °C for 6 h intervals.

Comparative study of physicochemical properties of dextran and reuteran synthesised by two glucansucrases that are highly similar in amino acid sequence

“…(2019), the endothermic peaks of the commercial dextran 500 and the water‐soluble alternan from Leuconostoc citreum ABK‐1 were determined at 78.1 °C and 78.5 °C, respectively. However, the mutan produced by L. mesenteroides NRRL B‐1118 showed an endothermic peak at a lower temperature of 70 °C (Evans et al ., 2020). The differences in the thermal behaviours of various α‐glucans may be related to their linkage compositions, structural organisation, and molecular configuration.…”

“…The alternan (composed of 58% (α1→6) and 42% (α1→3) linkages) produced by Lactobacillus reuteri SK24.002 was described as agglutinated granules with a web‐like structure (Miao et al ., 2015c; Song et al ., 2016). The water‐insoluble mutan (composed of 50% (α1→3) and 50% (α1→6) linkages) from Leuconostoc mesenteroides NRRL B‐1118 had a fibrous network microstructure similar to that of GtfO reuteran (Côté & Skory, 2012; Evans et al ., 2020). These phenomena suggest that the significant surface morphological differences of various α‐glucan polysaccharides may be attributed to the subtle differences in their linkage compositions, size distributions, and branching degrees.…”

Leuconostoc mesenteroides and Liquorilactobacillus mali strains, isolated from Algerian food products, are producers of the postbiotic compounds dextran, oligosaccharides and mannitol

“…mesenteroides and L. mali Algerian strains with high purity. The monomeric composition and IR spectra of purified EPS showed that they were glucans (Evans et al 2020 ; Synytsya and Novak 2014 ) with α-configurations (Münkel et al 2020 ). The additional analysis of methylation confirmed that the EPS produced by the six LAB were dextrans.…”