文献类型：期刊文献

英文题名：Structural elucidation of the exopolysaccharide from Streptococcus thermophilus XJ53 and the effect of its molecular weight on immune activity

作者：Xia, Wei[1,2,3];Han, Jin;Zhu, Shiming[2];Wang, Yilin[2];Zhang, Wenqing[2];Wu, Zhengjun[1,4]

机构：[1]Bright Dairy & Food Co Ltd, Dairy Res Inst, State Key Lab Dairy Biotechnol, Shanghai Engn Res Ctr Dairy Biotechnol, Shanghai 200436, Peoples R China;[2]East China Univ Sci & Technol, Sch Chem & Mol Engn, Shanghai Key Lab Funct Mat Chem, Shanghai 200237, Peoples R China;[3]130 Meilong Rd, Shanghai 200237, Peoples R China;[4]1518 Jiangchang West Rd, Shanghai 200436, Peoples R China

年份：2023

卷号：230

外文期刊名：INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

收录：;EI(收录号：20242816663507);WOS:【SCI-EXPANDED(收录号:WOS:000962807000001)】；

基金：Acknowledgments This work was supported by the Open Project Program of State Key Laboratory of Dairy Biotechnology (No. SKLDB2021-004) .

语种：英文

外文关键词：Streptococcus thermophilus; Exopolysaccharide; Molecular weight

摘要：EPS53, a homogeneous exopolysaccharide (EPS) was isolated from Streptococcus thermophiles XJ53 fermented in skimmed milk via anion exchange column chromatography. The relative molecular weight of EPS53 was above 6.7 x 105 g/mol; its repeating structural unit of EPS53 consisted of fl-T-Galp, fl-1,3-Galf, a-1,3-Glcp and fl-1,3,6-Glcp residues in a molar ratio of 1:1:1:1, with fl-T-Galp attached to the O-6 position of fl-1,3,6-Glcp,identical to the EPS produced from S. thermophilus SFi39. EPS53-D, purified under similar conditions as EPS53 except for the deproteinization of trichloroacetic acid (TCA), had a lower molecular weight but the same repeating structural unit. The effects of EPS53 and EPS53-D on proliferation, phagocytosis and nitric oxide (NO) release of macro-phage RAW264.7 were compared. EPS53 exhibited stronger immune activity than EPS53-D, suggesting that the molecular weight might have an important effect on the activity of EPS molecules. Treatment with TCA might affect the activities of native EPSs produced by fermentation.