Short-clustered maltodextrin provides cryoprotection by maintaining cell membrane homeostasis of yeast during frozen storage

Abstract

Cryoprotective polysaccharides have been extensively explored. We found that short-clustered maltodextrin (SCMD) effectively increased yeast viability. But the specific mechanism of SCMD affecting yeast is still not clear. Here, we detailedly analyze the effects of SCMD addition on cell membrane homeostasis. Firstly, the high-branched structure of SCMD was observed, and the microstructure of SCMD-protecting yeast was more integral. Analysis of membrane physicochemical property and glycerophospholipid metabolism demonstrated the fluidity of cell membrane of SCMD-protecting yeast was enhanced, as the relative abundances of glycerophospholipids with unsaturated acyl chains increased in comparison to Control yeast. Further, molecular dynamics simulations found that simplified SCMD could form more H-bonds with water molecules around lipid bilayers at 250 K to promote the mobility of lipid bilayers. Therefore, the hypothesis of “SCMD existence promotes the membrane fluidity under ice-crystal stress during frozen storage and helps maintain cell membrane homeostasis after thawing, increasing the thawed yeast viability” is proposed.