Unraveling the Molecular Mechanisms of Trehalose-Mediated Protection and Stabilization of Escherichia coli Lipid Membrane during Desiccation

Trehalose,a disaccharide renowned for its ability to stabilizebiomolecular architectures under strenuous conditions, finds extensiveuse in the cryopreservation of probiotics. A profound comprehensionof its molecular-level interactions is of great significance. It isnotable that current research in the realm of lipid-sugar interactionsprimarily employs single-component lipid bilayers, which are far frombeing representative of real cell membranes. Our investigation, however,utilizes molecular dynamics simulations to delve into the specificsof a realistic Escherichia coli membranethat encompasses a diverse array of lipid types, comprising fourteendistinct species, subject to varying hydration levels. The resultsof our study showcase that the reduction of hydration levels induceslipid ordering and the formation of gel phases, yet trehalose, byforming hydrogen bonds with lipid headgroups, serves to uphold fluidityand supplant the role of water. Moreover, our findings evince thataugmented trehalose concentrations lead to a slowdown in lipid motionand contribute to the maintenance of fluidity by way of endowing aviscous matrix. It is noteworthy that our conclusions lend supportto the notion that water replacement and vitrification, despite theirseemingly disparate nature, need not be considered mutually exclusivein a real bacterial membrane.