Physico-chemical characterization of a new heteropolysaccharide produced by a native isolate of heterofermentative Lactobacillus sp. CFR-2182.
A heterofermentative Lactobacillus sp. CFR-2182 was isolated from dahi samples and it was found to produce 8.0 and 20.5 g/L heteropolysaccharide (HePS) in EPS medium (a simplified synthetic medium) and modified MRS broth, respectively, after 72 h at 30 degrees C. The total carbohydrate, reducing sugar and moisture contents of the purified HePS were 74, 10.6 and 2 g, respectively, per 100 g on dry weight basis. The HePS produced in EPS medium had glucose and mannose in 17:1 ratio. The HePS was non-gelling and non-film forming type. It was completely soluble in water and 1 N sodium hydroxide solution. Gel permeation chromatography and HPLC analysis indicated considerable heterogeneity of the HePS, having three fractions with molecular weights ranging from 3.3 x 10(4) to 1.32 x 10(6) Da. The enzymatic hydrolysis of the HePS with pullulanase and alpha-amylase [with alpha(1-->4) linkage] indicated the presence of alpha(1-->6) and traces of alpha(1-->4) linkages, respectively. NMR analysis of the EPS revealed unique chemical shifts.
Vijayendra
S V N
SV
Food Microbiology Department, Central Food Technological Research Institute, Mysore, India. svnvijayendra@yahoo.com
Palanivel
G
G
Mahadevamma
S
S
Tharanathan
R N
RN
D003470:Culture Media; D005285:Fermentation; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007778:Lactobacillus / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000302:isolation & purification
D003470:Culture Media; D011135:Polysaccharides, Bacterial