Thermorheological mapping and molecular insights into salt-dependent gel-like network formation in Mortierella alpina chitin-like exopolysaccharide solutions
- 1Universidad Catolica de Santa Maria
Abstract
Fungal chitin-like exopolysaccharides are promising fermentation-derived materials, however the molecular-level determinants of their salt- and temperature-dependent gel-like behavior remain poorly understood. Here, a previously characterized Mortierella alpina exopolysaccharide was re-examined by integrating oscillatory rheology with all-atom molecular dynamics simulations. Frequency sweeps across 5-15 mg mL-1, two ionic media (0.154 mol L-1 NaCl and 0.28 mol L-1 LiCl), and 10-60 C were used to map liquid-like, transitional, and elastic-dominated regimes. Increasing concentration strengthened network behavior, but the two salts followed distinct pathways: NaCl promoted a more coherent progression toward elastic dominance and more thermorheologically compatible relaxation behavior, whereas LiCl produced a high-dissipation intermediate regime and stronger temperature dependence. Simulations of a minimal multichain model comprising eight GlcNAc10 oligomers at approximately 15.8 mg mL-1 showed that NaCl favored larger, more compact assemblies despite weak and short-lived Na+-oxygen coordination. LiCl formed sharper, longer-lived first-shell contacts but maintained smaller and more expanded assemblies. Ion-mediated interchain bridges were sparse and transient. The combined results show that local cation binding strength does not directly predict collective network formation and support a dynamic physical-network mechanism governed by salt-specific coupling among hydration, ion exchange, chain packing, and reversible interchain association.
Related
- Dynamic Protein Adduct Formation by Methylmercury: Molecular Targets, Ligand Exchange, and Toxicological Consequences
- FRET-guided integrative modeling resolves Mg2+-dependent RNA tertiary-contact formation
- Substituting a conserved histidine alleviates difluoroacetate-dependent isoaspartate formation in a fluoroacetate dehalogenase
- N6-Methyladenosine RNA Modifications Influence the Stability of FUS-Dependent Biological Condensate Formation.
- Cultivar-Dependent Variation in Silicon Accumulation and Phytolith Formation Revealed by Comparative Proteomic Analysis in Rice
BibTeX
@misc{goyzuetamamani2026thermorheological,
title = {{Thermorheological mapping and molecular insights into salt-dependent gel-like network formation in Mortierella alpina chitin-like exopolysaccharide solutions}},
author = {L. D. Goyzueta-Mamani and H. L. Barazorda-Ccahuana and M. D. Noseda and R. Alves de Freitas and C. R. Soccol and J. C. de Carvalho},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.05.749623},
url = {https://www.biorxiv.org/content/10.64898/2026.09.05.749623v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Thermorheological mapping and molecular insights into salt-dependent gel-like network formation in Mortierella alpina chitin-like exopolysaccharide solutions
AU - L. D. Goyzueta-Mamani
AU - H. L. Barazorda-Ccahuana
AU - M. D. Noseda
AU - R. Alves de Freitas
AU - C. R. Soccol
AU - J. C. de Carvalho
PY - 2026
DA - 2026/09/05
PB - bioRxiv
DO - 10.64898/2026.09.05.749623
UR - https://www.biorxiv.org/content/10.64898/2026.09.05.749623v1
AB - Fungal chitin-like exopolysaccharides are promising fermentation-derived materials, however the molecular-level determinants of their salt- and temperature-dependent gel-like behavior remain poorly understood. Here, a previously characterized Mortierella alpina exopolysaccharide was re-examined by integrating oscillatory rheology with all-atom molecular dynamics simulations. Frequency sweeps across 5-15 mg mL-1, two ionic media (0.154 mol L-1 NaCl and 0.28 mol L-1 LiCl), and 10-60 C were used to map liquid-like, transitional, and elastic-dominated regimes. Increasing concentration strengthened network behavior, but the two salts followed distinct pathways: NaCl promoted a more coherent progression toward elastic dominance and more thermorheologically compatible relaxation behavior, whereas LiCl produced a high-dissipation intermediate regime and stronger temperature dependence. Simulations of a minimal multichain model comprising eight GlcNAc10 oligomers at approximately 15.8 mg mL-1 showed that NaCl favored larger, more compact assemblies despite weak and short-lived Na+-oxygen coordination. LiCl formed sharper, longer-lived first-shell contacts but maintained smaller and more expanded assemblies. Ion-mediated interchain bridges were sparse and transient. The combined results show that local cation binding strength does not directly predict collective network formation and support a dynamic physical-network mechanism governed by salt-specific coupling among hydration, ion exchange, chain packing, and reversible interchain association.
ER -