Premium
Isolation and physical characterization of an exocellular polysaccharide
Author(s) -
Tuinier R.,
Zoon P.,
Olieman C.,
Cohen Stuart M. A.,
Fleer G. J.,
de Kruif C. G.
Publication year - 1999
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/(sici)1097-0282(199901)49:1<1::aid-bip1>3.0.co;2-b
Subject(s) - radius of gyration , molar mass , chemistry , size exclusion chromatography , hydrodynamic radius , multiangle light scattering , formic acid , chromatography , gel permeation chromatography , dynamic light scattering , analytical chemistry (journal) , polysaccharide , aqueous solution , sedimentation coefficient , nitric acid , polymer , scattering , light scattering , organic chemistry , chemical engineering , copolymer , physics , nanoparticle , optics , enzyme , engineering
The physical properties of a polysaccharide produced by the lactic acid bacterium Lactococcus lactis subsp. cremoris strain NIZO B40 were investigated. Separation of the polysaccharide from most low molar mass compounds in the culture broth was performed by filtration processes. Residual proteins and peptides were removed by washing with a mixture of formic acid, ethanol, and water. Gel permeation chromatography (GPC) was used to size fractionate the polysaccharide. Fractions were analyzed by multiangle static light scattering in aqueous 0.10 M NaNO 3 solutions from which a number‐ ( M n ) and weight‐averaged ( M w ) molar mass of (1.47 ± 0.06) · 10 3 and (1.62 ± 0.07) · 10 3 kg/mol, respectively, were calculated so that M w / M n ≈ 1.13. The number‐averaged radius of gyration was found to be 86 ± 2 nm. From dynamic light scattering an apparent z‐averaged diffusion coefficient was obtained. Upon correcting for the contributions from intramolecular modes by extrapolating to zero wave vector a hydrodynamic radius of 86 ± 4 nm was calculated. Theoretical models for random coil polymers show that this z‐averaged hydrodynamic radius is consistent with the z‐averaged radius of gyration, 97 ± 3 nm, as found with GPC. © 1999 John Wiley & Sons, Inc. Biopoly 49: 1–9, 1999