啤酒酵母培养条件对ATP生产的影响 Ⅰ.供氧对酵母合成ATP活性的影响

结合酵母细胞酶促合成ＡＴＰ的活性测试，在５Ｌ发酵罐中培养啤酒酵母，考察了通气对菌体生长和细胞活性的影响。实验结果表明：通气量的变化，对菌体的生长速度和得率具有明显的调节作用；采用氧限制方法培养的啤酒酵母用于ＡＴＰ生产时得率可达到１００％。通气量６．０Ｌ／（Ｌ·ｈ）时培养的酵母细胞用于ＡＴＰ生产的效率比在通气量６０Ｌ／（Ｌ·ｈ）下培养的酵母细胞提高５０％以上。     

国产重组酵母乙型肝炎疫苗抗体反应观察

目的　观察多批次国产重组酵母乙肝疫苗不同免疫程序免疫儿童的抗体反应。方法　 1994～ 1999年 ,按 0 ,1,6月和 0 ,1,2月免疫程序 ,分别应用 10批和 3批国产酵母乙肝疫苗 ,免疫 12 10和 3 54名 6～ 12岁儿童 ,观察免后 1年抗体反应 ,并分别进行 2～ 5年的随访观察。结果　酵母乙肝疫苗的安全性好。按 2种免疫程序、应用 10批疫苗免疫的 17组儿童在完成全程免疫后 1个月 (T7)时 ,抗体阳转率均高于 90 % ,抗体滴度范围在 96 0 4～ 619 0 1U /L之间 ,0 ,1,6和 0 ,1,2组抗 -HBs阳转率均值分别为 97 3 4 %和 99 13 % ,无、低应答率为 2 66%和 0 87%。免后抗体阳转率下降速率慢 ,抗体滴度下降快 ,但均在首针免后 3～ 5年保持一个稳定水平。 0 ,1,6组抗体峰值几何均值(GMT)显著高于 0 ,1,2组 (3 0 5 2 7;115 0 5U/L ,P <0 0 1) ,但免后 3～ 4年的随访观察未发现 0 ,1,6组抗体持久性优于 0 ,1,2组 (P >0 0 5)。结论　国产酵母乙肝疫苗生产稳定 ,具有较好的安全性和免疫原性     

Linkage analysis and identification of deletion in Alagille syndrome gene

Alagille syndrome (AGS) is a genetic disease and the responsible gene has already been mapped at 20p12. To more accurately detect the region of the AGS gene on the linkage map of chromosome 20p, 14 yeast artificial chromosome (YAC) clones were screened to construct a YAC contig in the candidate region and 13 locus markers and 2 sequence-tagged sites (STS) were ordered. Combining all of the analyses, a 1.3 Mb critical region from D20S507 to D20S61 for the AGS gene was identified. As the human Jagged 1 gene (JAGI) lies just in this region and is responsible for the AGS disease, the genomic DNA in an AGS family without a visible deletion were analyzed by single-strand conformational polymorphism (SSCP) and direct DNA sequencing, and a 2-bp (CT) deletion mutation at exon 26 of the JAGI was identified.     

A rapid absorbance-based growth assay to screen the toxicity of oligomer Aβ_(42) and protect against cell death in yeast

Multiple lines of evidence show that soluble oligomer forms of amyloidβprotein(Aβ42)are the most neurotoxic species in the brain and correlates with the degree of neuronal loss and cognitive deficit in Alzheimer’s disease.Although many studies have used mammalian cells to investigate oligomer Aβ42 toxicity,the use of more simple eukaryotic cellular systems offers advantages for large-scale screening studies.We have previously established and validated budding yeast,Saccharomyces cerevisiae to be a simple and a robust model to study the toxicity of Aβ.Using colony counting based methods,oligomeric Aβ42 was shown to induce dose-dependent cell death in yeast.We have adapted this method for high throughput screening by developing an absorbance-based growth assay.We further validated the assay with treatments previously shown to protect oligomer Aβ42 induced cell death in mammalian and yeast cells.This assay offers a platform for studying underlying mechanisms of oligomer Aβ42 induced cell death using gene deletion/overexpression libraries and developing novel agents that alleviate Aβ42 induced cell death.     

Efficacy and tolerability of a nutraceutical combination of red yeast rice,guggulipid, and chromium picolinate evaluated in a randomized,placebo-controlled,double-blind study

Hypercholesterolemia is the major risk factor in the development of coronary heart disease. Coronary heart disease is a leading cause of morbidity and mortality in many countries worldwide. An increasing attention is now paid to nutraceuticals development for prevention and cure of dyslipidemia, especially for patients who do not wish to use chemical statins. The cholesterol lowering effect and the tolerability of NutraforChol®, a nutraceutical product containing red yeast rice extract, guggulipid extract and chromium picolinate, was evaluated on subjects who had total cholesterol level 200−239 mg/dL and LDL cholesterol level 100-159 mg/dL. In this study, a randomized, placebo-controlled, double-blind study which consisted of 4 weeks run-in period and 8 weeks treatment period was performed. Based on the study results, NutraforChol® effectively decreased total cholesterol (−15.9 %) and LDL level (-19.9 %) after two weeks consumption. The total cholesterol and LDL reduction were maintained during 8 weeks study period. At study termination (week 8), there was a significant difference between total cholesterol level of NutraforChol® treated group (173.5 ± 21.7 mg/dL) and placebo-treated group (204.5 ± 22.8 mg/dL) (p < 0.05). In addition, there was a significant difference between LDL level at week 8 in NutraforChol® group (115.5 ± 22.2 mg/dL) and placebo-treated group (145.1 ± 23.7 mg/dL) (p < 0.05). The tolerability of NutraforChol® was also evaluated. There were no significant changes (p > 0.05) on renal and liver function parameters between baseline and study termination. Thus, NutraforChol® may be considered as a complementary or alternative safe nutraceuticals for the treatment of mild dyslipidemic subjects.     

酵母流加发酵生产中乙醇浓度的在线测量

研制了乙醇浓度在线监测仪 ,并对其在酵母流加生产中的应用情况进行了考察 .结果表明 ,采用乙醇浓度反馈流加培养方式 ,细胞产率和发酵活力可分别达到 0 .4 1 6g/ g和 980～ 1 1 0 0mL ,显示出良好的应用前景 .     

发酵法生产高纯度低聚果糖

将筛选得到的酵母添加于固形物质量分数为 2 5 %的普通级低聚果糖 (FOS)溶液中 ,以消除产品中的副产物葡萄糖 ,提高FOS的含量 .研究了固形物质量分数、起始 pH值、酵母添加量对消除葡萄糖的影响 ,得到了不含葡萄糖且FOS质量分数达 82 .85 %的产品 .后者再经果糖转移酶作用 ,于 5 0℃、pH 5 .5下反应 10h ,FOS质量分数可提高至 85 .2 3% .     

Association Between Histoplasma Exposure and Stroke

Enhanced understanding of Histoplasma capsulatum as a potential inflammatory/infectious cause of stroke could have profound effects on public health. Reduced risk of a stroke through prevention (vaccine development and primary prevention) and altering the clinical course of a TIA (secondary prevention) could be achieved. Seroepidemiologic correlation is a key initial step in providing evidence that this yeast infection may be associated with increased risk for TIA or stroke. Further observations conducted in an in vitro examination of intracellular growth and replication of Histoplasma capsulatum in human umbilical vein endothelial cells (Clonetics Inc, San Diego, Calif) and aortic smooth-muscle cells (ATCC, Manassas, Va) should enlighten the vascular pathogenesis. The Mycotic Research Center is also conducting a large endarterectomy study, prospectively evaluating patients with stroke for seroepidemiologic evidence and in vitro evaluation of vascular endothelium genomic for Histoplasma capsulatum antibodies and antigen, respectively.     

Wilson病基因突变酵母分析系统的建立

【目的】建立一种能够对Wilson病(WD)基因突变进行分析的方法,为众多的WD基因突变进行致病性和致病程度的分析。【方法】本试验应用的酿酒酵母是YPH252,及其CCC2基因突变型ccc2酵母细胞。应用酶切方法构建了寡拷贝酵母表达质粒pMA92。将ATP7B亚克隆到酵母表达质粒pMA92上,进行ccc2酵母的转化和筛选,Westernblot分析转化后酵母ATP7B的表达情况,在铜、铁、色氨酸缺陷型的酵母SD培养基上培养转化的细胞,进行酵母生长曲线的分析,并进行Fet3p氧化酶活性的测定。【结果】在ccc2酵母细胞内表达人的ATP7B可以弥补ccc2的运铜功能,使ccc2酵母细胞在铜、铁及亮氨酸缺陷型培养基上生长良好。【结论】ccc2酵母细胞是研究ATP7B功能的一种良好的细胞模型,单拷贝ATP7B的表达就可以代偿ATP7B的功能缺陷,从而建立了可以对ATP7B进行分析的酵母分析系统。