发展核分析方法研究富铬酵母中铬的化学种态和生物效应

Several kinds of nuclear analytical techniques, such as molecular neutron activation analysis (MAA) and synchrotron radiation X-ray absorption near-edge structure spectroscopy (XANES), combined with microbiological and biochemical methods, were applied to select a high-biomass chromium-rich yeast strain and optimize the cultivation conditions, thus, the preparation of chromium yeast was established. The distribution of Cr in subcellular structure, nucleic acid and protein in the chromium-rich yeast was determined. The experimental results indicate that 80.9% of total chromium are accumulated in the protoplast. During the process of cultivation, yeast cells are capable of accumulating large amounts of chromium and incorporating 84% into organic chromium, among which 67% exist in cytosol, and 1% in nuclei fraction. Chromium concentration in DNA is higher than that in RNA and protein. XANES spectra show that chromium valence states in chromium-rich yeast biomass are Cr(III). The experimental data indicate that brewer's yeast powder are capable of reducing Cr(VI) to Cr(III), which could potentially applied in environmental Cr(VI) contamination. The glucose-lowering effect of chromium-rich yeast on the experimental diabetic rats was studied. The levels of serum glucose, cholesterol (TC), glyceryl trioleate (TG), low density lipoprotein (LDL), insulin and C-peptide were significantly decreased, while the content of HDL was obviously increased. The results indicated that the chromium-rich yeast could improve glucose and lipid metabolism in diabetic rats.

发展核分析技术（分子活化分析、PSS、富集稳定性同位素示踪技术、扫描质子微秸耄┎⒔岷仙际酰芯扛踉诟桓踅湍钢械幕е痔霸谘窍赴榉帧⒑怂帷⒌鞍字实戎械姆植迹唤⒏呋钚愿踅湍讣捌渖锘钚晕镏实闹票讣际酰貌镅芯扛醯纳镄в陀胙宓鞍捉岷系幕疲沂靖踉谏锾迥诘淖饔没硖峁┛蒲б谰荨