Effects Of Saccharomyces Cerevisiae Glucose Tolerance Factor On Glucose Metabolism Of Adipocytes

Yeast Glucose Tolerance Factor (GTF) is a Cr binding polypeptide, consisted ofglycine, aspartic acid, glutamic acid and cysteine, Cr3+being its essential active center.GTF can cooperate with insulin stimulates glucose metabolism. In this experiment,Saccharomyces cerevisiae YSI-3.7yeast strain which fermentation property stably,have high biomass and high organic chromium content was selected as the originalstrain. YSI-3.7was cultured by fermentation and extracted by ammonia, then studiedthe influence on glucose metabolism in insulin-resistance adipocytes.The main resultsof this paper are as follows:Based on lab scale experiments,15L and50L fermentation was studied to testthe organic chromium content. Results showed that after50L fermentation the strainorganic chromium content was1234μg/g, total chromium content was1502μg/g andthe ratio of organic chromium was82%, the biomass was0.96g/100mL dry cell and6.00g/100mL wet cell. Its fermentation property was stable in fermentationexperiments and compared with the commercially available chromium its organicchromium content was2-5times. The strain has better production performance.Organic chromium was extracted by ammonia in high-chromium yeast cells.SuperdexTM75and Sephadex G25gel filtration chromatography was adopted topurify the extractive and five A254peaks were obtained, chromium peak was coincidewith the second A254peak. Then chromium peak was collected for further purificationby reverse phase high-performance liquid chromatography (RP-HPLC) and three A254peaks were obtained, chromium peak was coincide with the first A254peak. Chromiumpeak was collected for RP-HPLC again and one A254peak was obtained, chromiumpeak was coincide with it absolutely. The research showed that through multi-stepcolumn chromatography liquid phase pure GTF was received.3T3-L1adipocytes were selected as the research objects, insulin-resistant modelwas established by induction of10-7mmol/L insulin for48h. Purified GTF and othersources of chromium were added to the culture medium to study the effect of glucosemetabolism on insulin-resistant cells (chromium content reflected the amount of GTF).The results indicated when together with insulin, glucose consumption showed a dosedependent effect of GTF. When chromium concentration was1μg/mL, rosiglitazone,GTF, chromium picolinate and chromium trichloride can increase glucose consumption3.1times,2.5times,1.7times and1.2times. GTF can improve glucosemetabolism in insulin-resistant3T3-L1adipocytes and the effect was significantlyhigher than other chromium.GTF is a accessible、 easily absorbable and highly efficient source ofchromium.GTF which extracted by Saccharomyces cerevisiae YSI-3.7cooperativewith insulin can significantly furtherance cell glucose metabolism. Therefore, it canbe used as adjuvant treatment of diabetes or health food. This experiment provided thebasis research for the application of GTF.