ISSN:
1432-072X
Keywords:
Key words Biosynthesis of extracellular
;
polysaccharide
;
Lipid-linked intermediate
;
Lactococci
;
Polysaccharide
;
Undecaprenol
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Lactococcus lactis subspecies cremoris SBT 0495 produces the phosphopolysaccharide viilian, which consists of the repeating unit β-d-glucosyl-(1→4)-(α-l-rhamnosyl-(1→2))-(α-d-galactose-1-phosphoryl-(→3)-β-galactosyl-(1→4)-β-d-glucose. A lipid extract was prepared from cells in the late exponential phase of growth and was hydrolyzed by hydrochloric acid under mild conditions to split lipid-linked intermediates in the extract into lipid and sugar moieties. Both moieties were purified by chromatographic techniques and were characterized to identify intermediates of the viilian biosynthetic pathway. A polyisoprenoid isolated from the chloroform-soluble fraction of the hydrolyzed lipid extract was identified by mass spectrometry as undecaprenol. Saccharides isolated from the water-soluble fraction of the hydrolyzed lipid extract by anion-exchange chromatography, were characterized by glycosidic linkage analysis to discriminate sugar moieties of intermediates of viilian biosynthesis from compounds liberated from cell wall components. Some oligosaccharide analogues contain a glycerol residue, suggesting that these are fragments of glycosylglycerides and/or lipoteichoic acid. Three fragments were identified to be glucose, galactosyl-(1→4)-glucose, and rhamnosyl-(1→2)-galactosyl-(1→4)-glucose, which are in agreement with the structure of the repeating unit of viilian. These saccharides most likely represent the first three steps of the sequential assembly of the repeating unit of the undecaprenol assembly.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002030050720
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