Abstract:在有氧条件下,利用Q Sepharose Fast Flow离子交换层析和Blue Sepharose CL 6B亲和层析提纯克雷伯杆菌胞内甘油脱氢酶.酶的纯化倍数和回收率分别为 32.61 倍和 5.83%.通过SDS PAGE电泳测得该酶亚基的相对分子质量约为 34 000.该酶最适表观反应温度和最适反应pH值分别为60 ℃和11.在30 ℃以下及pH值10~12时,该酶具有良好的稳定性.在45 ℃和pH值11条件下,该酶以甘油和NAD 为底物的米氏常数Km分别为 0.75 mmol/L和 0.12 mmol/L.甘油脱氢酶对甘油的生理反应活性最大,对其它醇类如 1,2 丙二醇、乙二醇也有氧化能力.NH4 和Na 对酶有显著激活作用.巯基保护剂可明显地提高酶的活力.

Abstract:构建含有 B.subtilis 24 核黄素操纵子的整合型核黄素质粒 pRB40、pRB61 和 pRB63,研究了核黄素操纵子分别在B.subtilis 24R7染色体的 rib、amyE和thrC 位点整合对核黄素合成的影响.结果表明,核黄素操纵子通过单交换重组方式整合在上述位点可使核黄素合成量增加14%~19%,而通过双交换重组方式整合在 amyE 或 thrC 位点可使核黄素合成量增加 40% ~44%.增强核黄素操纵子在B.subtilis 24R7染色体上的稳定性可以提高核黄素的合成量.

Abstract:The effect of glucose feed on the fermentation of Bacillus thuringiensis BMB005 were investigated by feeding glucose at the exponential and stationary growth phases, respectively. In flasks, better effects were obtained by feeding glucose at the exponent

Abstract:Using the light microscope analytical method, the degradative process of tapioca starch with non-crystallized granule state by microorganisms was investigated in details. Beginning at the blowing out poles of starch granules, starch granules were graduall

Abstract:采用活性聚丙烯酰胺凝胶电泳和均质提取法相结合,从枯草芽孢杆菌(Bacillus subtilis)固体培养基发酵产物中分离得到了两种木聚糖酶. 薄层色谱和高压液相色谱分析结果进一步表明它们具有内切木聚糖酶的活力,分别定义为xyl Ⅰ和 xyl Ⅱ.两种酶具有相同的最适反应温度(50℃)和最适pH值(7.0).另外,还研究了内切木聚糖酶 xyl Ⅱ对小麦麸皮不溶性膳食纤维的作用.纸色谱分析结果表明,酶解产物中含有阿魏酰低聚糖.

Abstract:Ceramide are widely distributed lipid molecules in eukaryotic cells, and it becomes important in cosmetic industry in recent years. To study the possibility of producing ceramide from yeast, the ceramide content in yeast Yarrowia lipolitica was detected u

Abstract:采用有效容积为150 L的膨胀颗粒污泥床(EGSB)反应器和 400 L的一体式膜生物反应器(MBR)新型组合系统处理生活污水,首先通过模拟废水实验确定反应器的水力停留时间(HRT),在此基础上进行组合系统处理生活污水的中试研究,考察EGSB MBR组合系统处理生活污水的技术可行性. 结果表明,在温度 30 ℃、EGSB 水力停留时间为 0 8 h、混合液悬浮固体量(MLSS)在28 5 g/L,MBR的HRT为 2 h、MLSS 为 10 g/L、DO为 2 mg/L时,系统运行稳定,COD和NH3—N去除率分别为95%以上和90%以上,色度去除率大于 90%,悬浮固体(SS)和浊度几乎可以完全去除,出水水质优于城市污水再生利用———城市杂用水水质标准,同时组合系统污泥产量低,可大大减少污泥处理处置费用,是一项高效、节能的新型城市污水资源化技术.

Abstract:为提高魔芋葡甘聚糖性能,扩大其应用范围,用六偏磷酸钠与魔芋葡甘聚糖进行酯化反应. 采用红外光谱测得其产物的结构表征,并研究了其性能.结果表明:酯化改性的最佳条件为:m(六偏磷酸钠)∶m(葡甘聚糖)=1∶8,温度 55 ℃,pH值 2,时间 1.5 h.在此条件下,产物的粘度、溶胶稳定性、冻融稳定性、透明度均有改善,产物适用于冷冻食品等行业.

Abstract:The aim of this paper is to produce the active component from beef placenta and to determine its activity of stimulating fibroblast proliferation. The activity stimulating fibroblast proliferation in vitro was verified for the sample with molecular weigh

Abstract:以两个不同相对分子质量的燕麦β 葡聚糖为实验原料,配制成不同质量分数的溶液,对其流变学特性进行研究.结果表明:质量分数 0 2%~3%的燕麦β 葡聚糖溶液随着剪切速率增大而呈现剪切变稀,表现非牛顿流体行为,相对分子质量对流变性产生一定的影响.质量分数 3%的β 葡聚糖溶液可以形成触变环.动态测量结果表明,燕麦β 葡聚糖具有粘弹性和弱的凝胶特性,一定条件下可以形成凝胶. DSC测定结果显示,质量分数5%的燕麦β 葡聚糖凝胶的溶解温度为75 ℃.

Abstract:Strawberries were treated with a combination drying of vacuum freeze and hot-air(FAD) in this work. Energy consumption and physicochemical properties of different drying methods were compared with single hot-air drying and vacuum freeze drying. Favorate c

Abstract:采用硫酸、乙醇等提取,Sephadex G 50 及 RP HPLC技术纯化,从苦瓜中分离出苦瓜多肽 P,又称植物胰岛素,该技术优于过去的薄层层析纯化方法.皮下注射该多肽可降低正常小鼠和四氧嘧啶模型小鼠的血糖,口服无效.经胃蛋白酶、胰蛋白酶水解后,该肽降糖活性丧失.

Abstract:应用生物信息学方法分析了木聚糖酶初级序列中20种氨基酸同其最适温度之间的关系,发现在F/10家族中有正相关作用的氨基酸是W,负相关作用的是 A,D,H,S;理论上最高最适温度是119 8 ℃在G/11家族中有正相关作用的氨基酸是L,D,P,Y,负相关作用的是 H;理论上最高最适温度为105 6 ℃.惊奇地发现在不同家族中 D起不同的作用,这只能从它们各自不同的蛋白质空间结构上进行解释.从初级序列基础上证明了木聚糖酶的不同蛋白质家族有不同的热稳定性机制.

Abstract:采用Flavourzyme与Protamex复合蛋白酶对牛肉进行水解,并以水解度为指标,采用响应面分析对其酶解条件进行优化,建立了一个水解模型,其最优化条件为:底物质量浓度 4. 8g/dL,反应起始pH值7.0,水解温度52.5℃,水解时间9 h,在此条件下达到最大水解度50.65%.并对不同水解度水解产物的游离氨基酸含量进行了分析.

Abstract:利用溶剂萃取、薄层层析对大叶紫薇提取物中三萜化合物进行分离,通过 DSC,UV, IR和HPLC/MS对分离产物中具有降血糖的成分 3 进行结构分析,结果表明:以氯仿∶丙酮为展开剂,可在硅胶板中将大叶紫薇中三萜化合物有效分离。对分离出的成分 3,DSC测定其熔点为 283~287 ℃,焓值为43 727 J/g;UV最大吸收波长为 206 nm; MS测定其相对分子质量为 457; IR光谱符合乌苏果烷型结构.经分析,具有降血糖的成分3即为熊果酸.

Abstract:Traditional simultaneous distillation extraction (SDE) and solid-phase micro extraction (SPME) techniques were compared for their effectiveness in the extraction of volatile flavor compounds from the Chinese traditional Jinhua ham. 143 Jinhua ham volatil

Abstract:对Clostridium butyricum Z 10的生长特性研究表明,其最适生长温度为36 ℃,最低和最高生长温度分别为16 ℃和44 ℃;最适起始生长pH值为7.2,最低和最高起始生长 pH值分别为4 6和10 6;最高耐胆酸盐质量浓度为4 g/dL,起始氧化还原电位为-21 mV;丁酸梭状芽孢杆菌对青霉素不敏感,主要代谢产物为丁酸和乙酸.通过对生长因子、氮源的选择性研究,得出采用酵母膏做为生长因子,胰蛋白胨作为氮源有较好的效果.优化培养基试验得出当胰蛋白胨质量浓度为22 g/L,葡萄糖质量浓度为 10 g/L,盐酸半胱氨酸质量浓度为 0 5 g/L时,总菌体浓度可达到3 6×108个/mL.

Abstract:用环氧氯丙烷和海藻酸钠反应制得交联海藻酸钠,红外图谱、粘度和热稳定性质的改变证实了交联反应的发生.用正交试验法得到优化合成条件:温度 50 ℃,反应时间 3 5 h,环氧氯丙烷用量为绝干海藻酸钠质量的5 0%,pH值为10.通过交联作用,质量分数1%的海藻酸钠溶液粘度从560 mPa·s上升到 680 mPa·s. 以 1 5 ℃/min从 20 ℃升温到 70 ℃,交联产物粘度下降了95 mPa·s,而海藻酸钠下降了280 mPa·s.

Abstract:So far few works have been conducted to predict polyproline type II(PPII) secondary structure with machine learning approaches.On the base of preprocessing protein sequences, this paper predicts PPII secondary structure with BP type's neural network model

Abstract:采用氮蓝四唑(NBT)光化还原法、抗坏血酸—Cu2 —H2O2体系法和亚油酸体系法,对从野生灵芝中提取的有效活性物质,进行清除超氧自由基O2-·、羟基自由基·OH和脂过氧自由基ROO·的效果进行测定.结果表明,采用体积分数85%的丙酮,液固体积质量比为 15 mL∶1 g,超声20 min是灵芝有效成分提取的最佳工艺条件.灵芝提取物对自由基有较强的清除作用,在 3 种不同品种的灵芝提取物中,白灵芝的清除效果最佳,紫灵芝次之,而赤灵芝最差.

Abstract:The level of amino acid production with mutant strains requires accurate and feasible measurement, The method of simple paper chromatography was studied systematically in this paper, to measure the content of L-Isoleucine in broth. The results could b

Abstract:Using drosophila survival model, old-age rat model, croton oil induced mouse ear oedema model and mice model, the physiological functions of lycopene including anti-aging, anti-oxidation, anti-inflammation, and anti-coagulation were investigated. Results

Abstract:In this paper, the composition of aminal acids, classifications and extracting technology of Acria cinerea protein were studied. The continent of Acria cinerea protein was 56.84%, the essential aminal acids was 24.9% and of high utilization value, it was

Abstract:High hydrostatic pressure processing is a nonthermal preservation used in food industry. Combining high hydrostatic pressure with other food preserving techniques such as heat, pH, antimicrobials, modified atmosphere packaging, carbon dioxide, pulsed elec