一种禽蛋壳膜高效分离新方法

一种机械辗压 酸处理联合高效分离蛋壳壳膜的新方法.利用禽蛋石灰壳脆性好、蛋壳膜韧性强的特点,在合适的水分下,通过机械碾压、水中筛选,初步分离壳膜;再经稀酸处理,分离黏附在粗级蛋壳膜上的少量石灰壳,实现壳膜完全分离.结果表明,相对于现有方法,机械碾压 酸处理联合分选法最大程度保留了石灰壳及蛋壳膜原有的结构、成分与性质,酸用量大大减少,蛋壳膜回收率大大提高,达 79.0%,膜中钙残存量小于 0.29%.石灰壳回收率达 93%.石灰壳中膜残存量小于0.48%.该法可望用于大规模分离蛋壳膜和处理石灰壳.     

降解柠檬苦素菌株的筛选鉴定及其发酵条件的优化

为解决柠檬苦素脱苦问题,筛选了可降解柠檬苦素的菌株并优化该菌株的产酶条件。从多年生橘园的土壤和发酵时期的醋醅中筛选并分离出8株可降解柠檬苦素的菌株,对较好降解柠檬苦素的C-1-5、C-1-2-2、JJ-3菌株进行形态学观察和分子生物学鉴定,在单因素实验的基础上,选JJ-3菌株进行响应面法优化的发酵工艺。筛选得到的8株菌中C-1-5、C-1-2-2、JJ-3菌株的柠檬苦素降解率分别为27%、36%、38%。鉴定C-1-5菌株为纤维菌属(Cellulomonas sp.),JJ-3菌株和C-1-2-2菌株为苍白杆菌属(Ochrobactrum sp.)。单因素优化后C-1-5、JJ-3、C-1-2-2菌株柠檬苦素降解率分别提高至65.90%、72.79%、74.66%。通过响应面试验,JJ-3菌株最佳发酵工艺条件是:pH3.5,温度30℃,氮源为硝酸铵,菌接种量3×10⁸ CFU/mL。在此工艺条件下,柠檬苦素降解率为78.90%。优化后的菌株具有较高的降解率,可为柠檬苦素酶的研究提供帮助。     

表面活性剂Tween-80对Acidithiobacillus ferrooxidans硫氧化和硫代谢相关蛋白质基因表达的影响(英文)

研究了表面活性剂 Tween-80 对 Acidithiobacillus ferrooxidans ATCC 23270 生长、硫氧化和硫代谢相关典型基因表达的影响。结果表明,当培养基中含有 10 2g/L Tween-80 时,A. ferrooxidans 的生长以及其对不溶性底物(S0和 CuFeS2)的代谢得到了促进。在该条件下,经过 24 d 的生物浸出,黄铜矿的铜离子浸出率比对照组(不含 Tween-80)高 16%。FT-IR 光谱分析表明,这可能是由于 Tween-80 的存在而导致胞外多聚物成分发生变化而引起的。用 RT-qPCR 来分析 17 个硫代谢相关基因在 Tween-80 存在时的表达差异。胞外蛋白质基因表达下调表明了Tween-80 对细菌硫吸附作用的影响。硫代谢相关酶基因表达水平的变化为硫代谢的研究提供了参考。     

Comparative study on biosorption of Pb(Ⅱ)and Cr(Ⅵ)by Synechococcus sp.

The comparative study on adsorptions of Pb(Ⅱ)and Cr(Ⅵ)ions by free cells and immobilized cells of Synechococcus sp. was performed,in which different aspects including Zeta potential of the cells,the influence of pH,temperature and initial concentration of metal ions,as well as adsorption kinetics and mechanism were referred.The lyophilized free cells have a surface isoelectric point at pH 3,and the correlative experiment indicates that there is an electrostatic adsorption feature of Cr(Ⅵ)and Pb(Ⅱ). The i...     

对新时期实验师资队伍结构与素质要求的思辨

建设高水平国际知名的研究型大学,需要高水平的实验师资队伍.目前,高等院校的实验师资队伍的结构和素质状况与办学目标相差甚远,令人担忧.本文对此进行了分析,同时提出了新时期实验师资队伍结构和素质要求的新模型及其实现的几点设想与建议.     

对新时期实验师资队伍结构与素质要求的思辨

建设高水平国际知名的研究型大学，需要高水平的实验师资队伍。目前，高等院校的实验师资队伍的结构和素质状况与办学目标相差甚远，令人担扰，本文对此进行了分析，同时提出了新时期实验师资队伍结构和素质要求的新模型及其实现的几点设想与建议。     

Production and characterization of alkaline extracellular lipase from newly isolated strain Aspergillus awamori HB-03

A strain HB-03 to produce alkaline extracellular lipase was isolated from oil-rich soil samples and identified as Aspergillus awamori.The growth conditions and nutritional factors for lipase production by strain HB-03 were optimized,and the maximum lipase production of (45.9±2.3) U/mL was obtained at 30 °C and pH 7.0 after 36 h using olive oil (1%) and sucrose (0.5%) as carbon sources and combination of peptone (2%),yeast extract (0.5%) and ammonium sulfate (0.1%) as nitrogen sources.The lipase was purified...     

嗜酸氧化亚铁硫杆菌对环状硫和线状硫的氧化利用差异(英文)

比较了Acidithiobacillus ferrooxidans对环状硫(α-S)和线状硫(μ-S)的利用差异。A.ferrooxidans在这2种单质硫中生长和硫氧化的结果表明该菌对μ-S的利用与α-S明显不同。尽管生长300 h后该菌在2种单质硫基质中达到相同的细胞浓度、相同的pH和硫酸根离子浓度,但在初始阶段细菌细胞在μ-S中生长时的细胞生长速率、pH下降速率和硫酸根增加速率比在α-S中生长时明显快。A.ferrooxidans对这2种硫的初始吸附行为研究表明该细菌对μ-S的平衡吸附量明显高于α-S。SEM、DRIFTS和XRD结果表明,A.ferrooxidans对这2种单质硫表面进行了不同的修饰。选取了11个与硫吸附活化和代谢相关基因通过RT-qPCR进行差异表达分析,结果显示A.ferrooxidans在μ-S中生长时,与疏水性底物转运蛋白和硫代谢相关蛋白表达量比在α-S中生长时明显上调,而吸附和活化相关蛋白表达下调,表明μ-S比α-S易于被A.ferrooxidans适应和活化。     

高碱脉石低品位铜镍复合矿的诱变细菌浸出

金川低品位铜镍复合矿为高碱脉石的氧化—硫化混和矿 ,矿区无土著浸矿细菌。采用经诱变改良的外源混合T .f浸矿菌和控制矿浆 pH(<4 ) ,有效地浸出了该复合矿中的镍和铜 ;控制矿浆pH在细菌生长最适的范围内 ,钙、镁实际耗酸分别只占其总含量的 2 2 %～32 % ;铜、镍在不同浸出阶段表现为相反的浸出行为 ,酸浸时铜优先被浸出 ,菌浸时镍优先被浸出 ;渣样分析表明硫化镍、硫化铜的浸出机制为间接作用。物相分析表明这些浸出行为与浸出对象的赋存状态有关。     

Fractionation and characterization of polysaccharides from cyanobacterium Spirulina （Arthrospira） maxima in nitrogen-limited batch culture

By a sequentially selective extraction procedure, polysaccharides (PS) from cyanobacterium Spirulina (Arthrospira) maxima that can be bio-functionally healthy components were fractionated in four parts including the culture medium (PSCM), the external layers of the cell (PSEL), the cell wall (PSCW) and storage granules (PSSG). The four fractionated parts of polysaccharides were characterized by gas-liquid chromatography (GLC) equipped with FID and fused-silica capillary column (15 m×0.53 mm i. d.). The contents of PSCM, PSEL, PSCW and PSSG were about 2.0%, 2.6%, 10.0% and 52.0% to cell dry matter, respectively. Glucose was almost the only monosaccharide in PSSG and PSCW and most predominant in PSEL, while in PSCM, xylose, rhamnose and glucose were the main ones. Two uronic acids represented by glucuronic acid and galacturoic acid, six neutral monosaccharides including fucose, rhamnose, xylose, mannose, galactose and glucose, and two possible unidentified sugars were found in PSEL and PSCM. These data are valuable for the selective productions of high-added value sugars from Spirulina. Foundation item: Scholarship for Ph. D at FPMs, Belgium Biography of the first author: NIE Zhen-yuan, Engineer in biomedicine, born in 1963, majoring in biotechnology and bioengineering.