Partial characterization and immunostimulatory activity of exopolysaccharides from Lactobacillus rhamnosus KF5.
Lactobacillus rhamnosus KF5, a strain newly isolated from the faeces of a healthy human volunteer, has been shown to produce the exopolysaccharides (EPS) in skim milk. Two EPS fractions were separated from the fermented skim milk by removing proteins, ethanol precipitation, anion-exchange and gel permeation chromatography. Fraction S1, with a low average molecular weight of 1.36 × 10(4)Da, was composed of glucose, arabinose, glucosamine, galactosamine and galactose in an approximate molar ratio of 2.03:1.29:1.25:0.72:0.61. Such monosaccharide composition of the exopolysaccharide by lactic acid bacteria has not been reported so far, and S1 is likely to be an unusual type of microbial EPS. Whilst Fraction S2, with a high average molecular weight of 1.23 × 10(6)Da, contained rhamnose, glucose and galactose in a molar ratio of approximately 1.73:1.47:1.00. Both of EPS fractions could significantly stimulate splenocyte proliferation in vitro, indicating two EPS fractions had the potential immunomodulatory activity.
School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; State Key Laboratory of Dairy Biotechnology, Technology Center of Bright Dairy & Food Co. Ltd., Shanghai 200436, China.
Li
L
Shao
State Key Laboratory of Dairy Biotechnology, Technology Center of Bright Dairy & Food Co. Ltd., Shanghai 200436, China.
Zhengjun
Z
Wu
School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Hao
H
Zhang
School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Wei
W
Chen
School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China. Electronic address: ailianzhong@hotmail.com.
Lianzhong
L
Ai
School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; State Key Laboratory of Dairy Biotechnology, Technology Center of Bright Dairy & Food Co. Ltd., Shanghai 200436, China. Electronic address: awy7677@hotmail.com.
Benheng
B
Guo
D000276:Adjuvants, Immunologic / Q000737:chemistry* / Q000494:pharmacology*; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D052201:Lacticaseibacillus rhamnosus / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D009005:Monosaccharides / Q000032:analysis; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000494:pharmacology*; D013154:Spleen / Q000276:immunology
D000276:Adjuvants, Immunologic; D009005:Monosaccharides; D011135:Polysaccharides, Bacterial
Exopolysaccharide; Immunostimulatory activity; Isolation; Lactobacillus rhamnosus