title: Structural studies of the cell wall polysaccharides from three strains of Lactobacillus helveticus with different autolytic properties: DPC4571, BROI, and LH1.
abstract: Lactobacillus helveticus is traditionally used in dairy industry as a starter or an adjunct culture for manufacture of cheese and some types of fermented milk. Its autolysis releases intracellular enzymes which is a prerequisite for optimum cheese maturation, and is known to be strain dependent. Autolysis is caused by an enzymatic hydrolysis of the cell wall peptidoglycan (PG) by endogenous peptidoglycan hydrolases (PGHs) or autolysins. Origins of differences in autolytic properties of different strains are not fully elucidated. Regulation of autolysis possibly depends on the structure of the cell wall components other than PG, particularly polysaccharides. In the present work, we screened six L. helveticus strains with different autolytic properties: DPC4571, BROI and LH1. We established, for the first time, that cell walls (CWs) of these strains contained polysaccharides, different from their CW teichoic acids. Cell wall polysaccharides of three strains were purified, and their chemical structures were established by 2D NMR spectroscopy and methylation analysis. The structures of their repeating units are presented.
authors.affiliation: National Research Council, Ottawa, Canada.
authors.forename: Evgeny
authors.initials: E
authors.lastname: Vinogradov
authors.forename: Florence
authors.initials: F
authors.lastname: Valence
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Maes
authors.forename: Iva
authors.initials: I
authors.lastname: Jebava
authors.forename: Victoria
authors.initials: V
authors.lastname: Chuat
authors.forename: Sylvie
authors.initials: S
authors.lastname: Lortal
authors.forename: Thierry
authors.initials: T
authors.lastname: Grard
authors.forename: Yann
authors.initials: Y
authors.lastname: Guerardel
authors.forename: Irina
authors.initials: I
authors.lastname: Sadovskaya
mesh_terms: D001329:Autolysis / Q000378:metabolism; D002236:Carbohydrate Conformation; D002473:Cell Wall / Q000737:chemistry* / Q000378:metabolism; D052198:Lactobacillus helveticus / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008954:Models, Biological; D011134:Polysaccharides / Q000032:analysis* / Q000378:metabolism
chemical_list: D011134:Polysaccharides
keywords: Autolytic properties; Cell-wall polysaccharide; Lactobacillus helveticus; Structure