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Updated: Jan 12, 2026

Formulations for Freeze-drying of Bacteria and Their Influence on Cell Survival
Published on: August 3, 2013
Polysaccharides in cryopreservation: multidimensional systematic review of extremophilic traits and the role of
B M Guerreiro1, J C Lima2, J C Silva3
1UCIBIO - Applied Molecular Biosciences Unit, Department of Chemistry, School of Science and Technology, NOVA University Lisbon, Caparica, Portugal; Associate Laboratory i4HB - Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, Caparica, Portugal.
Abstract:
Cryopreservation of biological matter has accumulated apex biomedical interest for its potential in elongating the shelf-life of biological matter in a state of suspended animation. In Nature, extremophilic microorganisms have an outstanding ability of surviving in habitats where extreme cold, heat, salinity and acidity defy the established boundaries for life. Through Darwinian selective adaptation, they have developed biochemical defense strategies to counteract lethal stimuli. Here, we have compiled an extremophilic EPS structure-function relationship database (XPOL-DB) which aggregates reports on 145 extremophilic and mesophilic EPS, for a total of 128 biochemical and establishes the psychrophilic chemical profile for cold adaptation. Overall, psychrophilic EPS are highly-branched, polyanionic, elongated structures of increased flexibility and molecular weight (16 - 300 MDa), with predominant expression of polar monomers (GalNAc, GalA, GlcNAc, GlcA) - compared to the linear, rigid, neutral thermophilic EPS. The significant EPS similarity between psychrophiles and halophiles suggests ice growth and extreme salinity are rooted in a shared mechanism of physical membrane destabilization, for which similar chemical traits can dualistically imbue freeze tolerance and salt tolerance. Psychrophiles are exciting testbeds for the mapping of how extreme cold selects for cryobiological EPS adaptation; and can fuel reverse engineering efforts to design optimal bio-based, non-cytotoxic cryoprotectant polysaccharides.
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