三孢布拉霉菌发酵生产β-胡萝卜素的代谢调控

[目的]研究三孢布拉霉菌发酵生产β-胡萝卜素的代谢调控途径,为通过优化发酵培养条件来提高β-胡萝卜素的产量提供依据和参考。[方法]采用紫外分光光度计测定β-胡萝卜素的含量,优化正负菌孢子接入种子培养基的接种比例,通过对三孢布拉霉菌发酵生产β-胡萝卜素的代谢调控分析,确定最佳补液时间,优化培养温度和接种比例来提高β-胡萝卜素的产量。[结果]最佳孢子接种比例为正菌∶负菌=10∶1,最佳补液时间为52 h,最佳培养温度为27℃,最佳种子液接种比例为8%。[结论]通过对菌体生长代谢的分析优化了培养条件,并将β-胡萝卜素的产量从1.45 g/L提高到2.26 g/L,产量提高了55.9%,取得了较好的效果,为β-胡萝卜素的工业化生产奠定了基础。     

鸡TGF-β2基因启动子区多态性分析

为了研究鸡TGF-β2基因启动子区的SNP及其对启动子功能元件的影响,采用PCR-SSCP方法对16个鸡种的TGF-β2启动子区的554~824 bp(即3号染色体的19 433 476~19 433 746 bp)进行基因分型,经测序,共检测到3个有效的SNPs位点,分别是679位点的C/G,699位点的G/A,774位点的T/C。其中大骨鸡和太湖鸡在3个位点均检测到SNP存在,AA鸡在3个位点都没有发现SNPs。分别利用生物信息学软件JASPAR和MethPrimer预测TGF-β2基因启动子区转录因子结合位点和CpG岛,发现SNP位点可改变转录因子结合位点且位于CpG岛上,表明TGF-β2启动子区SNPs可能通过不同方式影响基因表达调控。     

18β-甘草次酸吡啶酰胺衍生物体外抗肿瘤活性研究

本试验研究18β-甘草次酸吡啶酰胺衍生物6c、10c、11c对HeLa、SMMC-7721、SGC-7901细胞增殖的影响。利用MTT法检测18β-甘草次酸吡啶酰胺衍生物6c、10c、11c对HeLa、SMMC-7721、SGC-7901细胞的抑制率;利用Hoechst-33258细胞凋亡染色试剂盒检测细胞凋亡情况;用Annexin V-FITC/PI双染法检测细胞凋亡率;蛋白质免疫印迹法检测相关蛋白表达水平;通过检测Caspases-3的活性进一步说明用药组诱导细胞凋亡的情况。结果表明,18β-甘草次酸吡啶酰胺衍生物6c、10c、11c对HeLa、SMMC-7721、SGC-7901细胞增殖均有抑制作用及促凋亡作用,且呈浓度依赖性,经t检验均有统计学意义(P<0.05)。18β-甘草次酸吡啶酰胺衍生物6c、10c、11c可诱导HeLa、SMMC-7721、SGC-7901细胞凋亡。     

中国大豆蛋白亚基构成分析与缺失部分亚基的特异大豆品种的筛选

大豆蛋白亚基组成的不同直接影响大豆蛋白的加工特性与营养特性。本研究利用SDS-PAGE电泳分析大豆蛋白质组成并提出了便捷的样品预处理方法。对1 624个中国大豆栽培品种的分析结果表明,构成大豆蛋白的主要亚基均有一定变异,同时,结合Western Blot分析,首次在中国大豆栽培品种中发现了β-伴大豆球蛋白的β-亚基缺失的大豆品种,为大豆蛋白质的品质改良育种和加工理论研究提供了重要的材料。     

甘氨酸-β-环糊精对蒽的增溶、解吸行为研究

为改善β-环糊精的水溶性,将β-环糊精和甘氨酸在碱性条件下用环氧氯丙烷连接起来,得到水溶性极好的甘氨酸-β-环糊精,研究了甘氨酸-β-环糊精对蒽的增溶、解吸行为,考察了pH值、甘氨酸-β-环糊精初始浓度、温度、不同环糊精类型对蒽解吸的影响。结果表明:甘氨酸-β-环糊精对蒽的增溶效果增强显著,其50 g/L时对蒽的增溶倍数可以达到20多倍,甘氨酸-β-环糊精对蒽的解吸随pH值的升高而降低,升高温度和甘氨酸-β-环糊精初始浓度有利于蒽的解吸,甘氨酸-β-环糊精对蒽的解吸要好于α-环糊精和β-环糊精,甘氨酸-β-环糊精对蒽污染土壤的解吸符合准二级动力学模式。该静态解吸研究可以为蒽污染土壤的修复提供基础信息。     

灵芝细胞中异源表达透明颤菌血红蛋白基因提高胞外多糖的产量

在灵芝(Ganoderma lingzhi)中异源表达透明颤菌血红蛋白(Vitreoscilla hemoglobin,VHb)基因,采用一氧化碳差异波谱分析的方法检测转基因菌株的生物活性,并对野生型菌株和工程菌株进行发酵,通过荧光定量PCR对灵芝多糖生物合成途径上的葡萄糖磷酸变位酶(α-phosphoglucomutase,PGM)、尿苷二磷酸葡萄糖焦磷酸化酶(uridinediphosphate glucose pyrophosphorylase,UGP)和β-1,3-葡聚糖合酶(β-1,3-glucan synthase,GLS)3个基因的转录水平进行分析。研究表明:透明颤菌血红蛋白基因(Vitreoscilla hemoglobin gene,vgb)在灵芝中能够成功表达,并且具有生物活性;工程菌株中胞外多糖的最高产量达0.83g/L,比野生型菌株提高了88.6%;与野生型菌株相比,工程菌株中多糖生物合成途径上PGM、UGP和GLS基因的相对表达量分别是1.52、1.55和3.85。异源表达透明颤菌血红蛋白基因是提高灵芝胞外多糖产量的一种有效方法。     

The agronomic performance and nutritional content of oat and barley varieties grown in a northern maritime environment depends on variety and growing conditions

Warmer temperatures and increasing interest in high provenance food and drink products are creating new opportunities for cereal growing in northern Europe. Nevertheless, cultivation of oats and barley in these areas for malting and milling remains a challenge, primarily because of the weather, and there are few reports of their nutritional content from this region. In this study, trials in Orkney compared agronomic characteristics and nutritional content of recommended UK oat and barley varieties with Scandinavian varieties over three years. For a subset of varieties, nutritional content was compared with samples cultivated in more southerly sites. For Orkney, barley was considered a more suitable crop than oats because varieties matured earlier. In both crops, Scandinavian varieties matured earlier than UK varieties and some produced comparable yields. The range of values for macronutrients and minerals in oats and barley in Orkney were similar to those reported previously for other locations, but there were some significant differences attributable to variety and year. Compared with grain samples from more southerly locations, oats in Orkney had a significantly lower β-glucan and higher sodium content. The lower β-glucan may have resulted from higher rainfall and lower temperatures during the months of grain filling and maturation.     

响应面法优化沙拉沙星/β-环糊精包合物制备工艺与稳定性评价

为制备沙拉沙星/β-环糊精包合物微囊,解决沙拉沙星原药溶解度低,理化性质不稳定的问题.通过响应面法优化沙拉沙星/β-环糊精包合物的制备工艺,采用液相色谱法对沙拉沙星/β-环糊精包合物进行载药量及溶解度测定,以干燥失重试验和影响因素试验对沙拉沙星/β-环糊精包合物的含水量与稳定性进行评价.结果显示,优化后的包合工艺参数为...     

Research progress of organic solute transporter α/β in bile acid metabolism

The organic solute transporter α/β （OSTα/β） is a recently discovered transporter that controls bile acid secretion into portal blood stream in the basal lateral membrane of intestinal epithelial cells. OSTα/β is a compound composed of 2 subunits, OSTα and OSTβ. Only when the 2 subunits are expressed at the same time, they exist stably and function properly. It is responsible for the transmembrane transport of organic solutes such as bile acids in a way of easy diffusion. OSTα/β is regulated by bile acid receptor, also named as farnesoid X receptor （FXR）. Studies showed that the bile acid synthesis in OSTα deficient mice is decreased, while the bile acid content in the urine is increased. It is worth mentioning that the single gene mutation leads to OSTβ deficiency in the patients with clinical symptoms such as chronic diarrhea and cholestatic liver disease. This paper reviews the structure, function and role of OSTα/β in enterohepatic circulation and the diseases caused by loss of OSTα/β.     

红笛鲷血清性类固醇激素周年变化的初步研究

应用放射免疫分析法测定红笛鲷雌、雄鱼血清性类固醇激素雌二醇、睾酮和孕酮的周年变化水平。结果表明,雌、雄鱼血清雌二醇、孕酮的变化趋势相似,3～10月雌二醇水平较低,11月以后不断升高,至次年2月雌鱼达到1257．46±447．20pg／mL,雄鱼达到1179．14±322．50pg／mL;4、5月孕酮水平较高,雌鱼在5月达到高峰118．49＋18．45ng／mL,雄鱼4月达到高峰109．98±60．97ng／mL,之后一直在比较低水平波动;雄鱼睾酮水平有一定规律性,3～9月一直处于比较高水平,8月达到高峰0．27±0．24ng／mL,而雌鱼睾酮水平周年变化没有规律性,最高水平在6月,达到0．28±0．13ng／mL。