کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
7789825 1500641 2015 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Physicochemical characterization of exopolysaccharides produced by Lactobacillus rhamnosus on various carbon sources
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Physicochemical characterization of exopolysaccharides produced by Lactobacillus rhamnosus on various carbon sources
چکیده انگلیسی
The impact of five carbohydrate sources (glucose, maltose, galactose, sucrose, and lactose) on the chemical composition, structure, morphology, and physicochemical properties, as well as, viscosity of exopolysaccharides (EPSs) produced by Lactobacillus rhamnosus E/N was investigated. GLC-MS analysis and 2DNMR spectroscopy showed that the EPSs had the same primary structure independently of the carbon source used in the growth medium. The following EPS composition was elucidated: four rhamnose, two glucose, and one galactose residue with a pyruvate substituent. Molecular masses (Mw) were determined by gel permeation chromatography, which revealed differences in Mw distribution. EPS-Gal, EPS-Suc, and EPS-Lac showed heterogenic fractions of a high and low molecular weight, while EPS-Mal and EPS-Glc contained only a high-molecular-weight fraction. AFM microscopy revealed morphological differences in chain length, thickness, and branching. Differences in the Mw ratio and thickness of the polymer chain were correlated with high viscosity of EPS solutions. Our results indicate that a single bacterial strain, depending on the carbon source in the medium, can produce EPSs of different rheological properties.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Carbohydrate Polymers - Volume 117, 6 March 2015, Pages 501-509
نویسندگان
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