学术报告-GenomicandFluxomicAnalysisofCarbohydrateMetabolisminBifidobacteriumspp:HumanSymbioticBacteria.
发布时间 :2011-10-08  阅读次数 :2274

报告题目:Genomic and Fluxomic Analysis of Carbohydrate Metabolism in Bifidobacterium spp:  Human Symbiotic Bacteria.
报  告  人:Neil Philip John Price, PhD
National Center for Agricultural Utilization Research                    
U. S. Dept. of Agriculture, Agricultural Research Service    
1815 N. University St.  Peoria, IL  61604
报告时间:10月10日 上午10:00
报告地点:徐汇校区哲生馆112会议室
组织单位:生命科学技术学院分子微生物代谢实验室
上海交通大学生命科学技术学院

Abstract
Bifidobacteria are gram-positive microorganisms widely applied in fermented dairy products due to their health-promoting effects.  Bifidobacterium ssp. may also represent up to 91% of microbial gut population in the infant colon, but considerably less in adults.  Fructose-6 phosphate phosphoketolase (F6PPK) is a key enzyme of the so-called "bifid shunt", a unique Bifidobacterium ssp. metabolic pathway involved in direct cleavage of fructose-6-phosphate to erythrose-4-phosphate and acetyl phosphate.  Furthermore, bifidobacteria lack genes for glycolysis and gluconeogenesis pathways.  Results of isotopic labeling experiments with 13C-fructose confirm that the bifid shunt is the predominant pathway for the degradation of carbohydrates by Bifidobacterium ssp., by-passing glycolysis.  The fractional distribution of 13C into carbohydrate and fatty acid metabolites was analyzed by GC-EI-MS.  The acetate derived from sugars via the bifid shunt is both secreted and incorporated into the Bifidobacterium de novo fatty acids.  Moreover, several metabolic “chase” experiments have been undertaken using probiotic oligosaccharides, and human milk oligosaccharides, and differential pathways are reported for B. longum and B. infantis strains.  These finding are consistent with our genome sequencing of these strains, and suggest ways by which B. infantis has adapted to the environment of the infant human gut.