灵芝菌丝体多糖的超滤提取及其抗氧化活性的研究

考察了超滤浓缩醇沉法提取发酵灵芝菌丝体多糖,与减压浓缩法相比,多糖含量、多糖得率均高于后者,所得多糖的品质得到提高,减轻了后续多糖纯化的负担。灵芝菌丝体粗多糖对羟自由基.OH(HFR)有较好的清除能力,在一定范围内清除率与多糖浓度呈正相关,超滤浓缩醇沉法提取灵芝菌丝多糖的.OH清除率高于减压浓缩醇沉法。     

灵芝茵丝体多糖的超滤提取及其抗氧化活性的研究

考察了超滤浓缩醇沉法提取发酵灵芝茵丝体多糖,与减压浓缩法相比,多糖含量、多糖得率均高于后者,所得多糖的品质得到提高,减轻了后续多糖纯化的负担.灵芝菌丝体粗多糖对羟自由基·OH(HFR)有较好的清除能力,在一定范围内清除率与多糖浓度呈正相关,超滤浓缩醇沉法提取灵芝茵丝多糖的·OH清除率高于减压浓缩醇沉法.     

超滤膜分离香菇多糖的研究

以本地劣质香菇为原料,利用超滤膜装置对浸提的香菇多糖进行分离。同时对超滤过程的阻力及传质特性进行分析,并建立超滤过程的修正凝胶极化模型。经过实验获得香菇多糖提取率5.7%,多糖质量分数89.2%,说明利用超滤方法分离浓缩香菇多糖是有效的工艺手段。     

猕猴桃果水溶性多糖的超滤膜分离研究

以猕猴桃果为原料,利用超滤膜装置对浸提的猕猴桃果多糖进行分离。同时对超滤过程的阻力及传质特性进行分析,并建立超滤过程的修正凝胶极化模型。经过实验获得猕猴桃果多糖提取率5.7%,多糖质量分数89.2%,表明利用超滤方法分离浓缩猕猴桃果多糖是有效的工艺手段。     

超滤法纯化C群脑膜炎球菌荚膜多糖降解物的工艺优化

目的优化超滤法纯化C群脑膜炎球菌荚膜多糖降解物的工艺。方法以截留分子量为300 000的超滤膜对C群脑膜炎球菌荚膜多糖降解物进行超滤分离,以膜通量和多糖回收率为评价指标,优化方法中的超滤膜材质(300 k Da的聚醚砜膜和再生纤维素复合膜)、透析次数(1~6次)、超滤缓冲液(0.15 mol/L Na Cl、0.5 mol/L Na Cl、50 mmol/L的PBS和H2O)、多糖初始溶解浓度(0.25、0.5和1 mg/m L)和超滤方式(浓缩补液超滤和恒体积超滤)。采用最佳条件对C群脑膜炎球菌荚膜多糖降解物进行检测。结果 C群脑膜炎球菌荚膜多糖降解物的最佳超滤条件为:以再生纤维素复合膜为超滤膜,0.15 mol/L Na Cl为超滤缓冲液,透析次数为5次,多糖初始溶解浓度为1.0 mg/m L,超滤方式为浓缩超滤。该方法可有效去除C群脑膜炎球菌荚膜多糖降解物中较大分子量的多糖组分,多糖回收率在80%以上,且可在一定程度上降低多糖水解物的内毒素含量。结论成功优化了超滤法纯化C群脑膜炎球菌荚膜多糖降解物的工艺,显著提高了工作效率。     

膜分离技术提取米糠脂多糖的研究

米糠是富含植物脂多糖的植物资源。本文就米糠脂多糖制备过程中 ,采用超滤和纳滤进行了分离浓缩米糠脂多糖提取液的尝试。结果表明 ,超滤后米糠脂多糖提取液中蛋白和多糖杂质含量分别降低 85 .5 %和 89.6 %。采用不加水循环纳滤的方式 ,浓缩倍数可达 8倍 ,同时米糠脂多糖浓缩液中的 87.4%的无机盐可除去。     

超滤提取黄芪多糖的工艺研究

采用超滤法测定了黄芪多糖的分子量分布;以截留分子量为200 kDa1、0 kDa的超滤膜对黄芪多糖进行超滤分离,考察了压力、温度、流速、初始料液浓度等对超滤提取的影响,确定最佳超滤提取条件为:初始料液浓度20 g.L-1、压力0.35 MPa、温度30℃、进料流速0.467 L.s-1,此条件下多糖含量由36.0%提高到86.8%。有效实现了黄芪多糖提取液中活性多糖与大分子蛋白多酚等物质的分离。     

用超滤过程浓缩纯化羊栖菜粗多糖浸提液

将超滤技术应用于羊栖菜粗多糖浸提液的浓缩纯化,结果表明,灰分脱除率达到92．3％,蛋白质的脱除率达到79．85％,脱盐率大于98．9％,脱色率达到91％,多糖的截留率为90．96％,多糖制品的纯度达到86．4％。     

羊栖菜多糖的提取及其在化妆品中的应用

羊栖菜作为一种重要的海洋生物资源,含有丰富的营养成分,从羊栖菜中提取的水溶性多糖具有抗肿瘤、降血脂、降血糖、免疫调节等功效。采用水提、H_2O_2脱色、超滤浓缩等方法提取羊栖菜多糖并提出其相关化妆品的配方设计与制备方法。最后得到羊栖菜多糖提取液中的粗多糖质量浓度为3.67mg/mL,提取率为1.49%;羊栖菜多糖精华液、润肤水、润肤乳的感官评价和理化指标均达到化妆品行业标准的要求。     

苏云金芽孢杆菌发酵液后处理工艺研究进展

介绍了苏云金芽孢杆菌发酵液后处理工艺研究进展.超滤法和沉淀法可以实现苏云金芽孢杆菌发酵液的浓缩,喷雾干燥法、碱溶-超滤法、膜过滤技术可以回收发酵液杀虫活性成分.     

SMP形成与降解机制分析及其对MBR膜过滤的影响

以膜生物反应器(membrane bioreactor,MBR)中活性污泥为研究对象,考察了溶解性微生物代谢产物(soluble microbial product,SMP)的形成及降解机制,并探讨了SMP对膜过滤的影响。实验结果表明,在基质存在时反应器内的SMP主要以基质利用相关型产物(utilization associated products,UAP)为主;当基质耗尽后,生物生长相关型产物(biomass associated product,BAP)浓度增加;内源呼吸过程中BAP的产出主要来源于松散胞外聚合物(loosely bound EPS,LB)的水解;通过傅里叶变换红外光谱(FTIR)检测表明,UAP主要由多聚糖和蛋白质组成,而BAP主要是多聚糖和腐殖酸;与UAP相比,膜对BAP截留效果较好,最佳的水力停留时间(hydraulic retention time,HRT)时MBR出水同时包含UAP及BAP,BAP浓度与膜过滤阻力呈显著正相关。     

天然有机物对国产纳滤膜的污染及清洗效果研究

为考察水体中天然有机物(NOM)对纳滤膜性能产生的影响,以腐殖酸(HA)、牛血清蛋白(BSA)和海藻酸钠(SA)分别模拟水中常见NOM,腐殖质、蛋白质和多糖,对国产NF-1812纳滤膜进行单组分及其混合物定性定量有机污染及清洗实验。结果表明,有机污染造成膜通量下降,膜污染程度为SA>HA>BSA;NOM截留率可稳定在99.2%~99.6%;膜污染阻力主要为浓差极化阻力,其次是凝胶层阻力和内部污染阻力,有机污染液综合黏度和综合含量越大,浓差极化阻力的比例越高;对多组分有机污染膜进行错流速度9 cm/s的物理水力清洗和pH=10.0的质量分数分别为0.1%的NaOH+0.025%Na-SDS化学药剂清洗,膜通量、NOM截留率、苦咸水截留率、SEM成像均恢复至原膜状态,纳滤膜清洗效果良好,适用于中国西北苦咸水地区。     

介孔分子硅剂改善茶浓缩膜结构特性应用研究

为有效提高功能性茶浓缩反渗透膜的回收效率和抗污性能,探究了3种介孔分子硅材料(MCM-41、SBA-15和MCFs)对浓缩膜面聚酰胺层聚合形成过程的结构影响。结果表明,添加质量分数0.02%经磺化预处理的MCM-41于间苯二胺水相可接枝酰氯基团,形成的聚酰胺结构层峰谷粗糙跨度仅为220 nm且交联紧致,膜抗拉伸强度增加37.8%;SBA-15和MCFs相膜面峰谷跨度达500~780 nm,横向褶皱和团聚,结构存在孔道塌陷;改性膜在3 h内对茶多酚、茶多糖、茶蛋白即可达到最大浓缩度,减少50%浓缩时间;MCM-41和SBA-15膜长时间运行的浓缩降率仅为2.8%~6.1%,48 h下降率比显示改性膜达标使用时长增加112.5%~137.5%,亲水性和抗污堵能力均大幅提升,可有效满足功能化茶浓缩精度。     

Nanofiltration for the Recovery of Low Molecular Weight Polysaccharides and Polyphenols from Winery Effluents

A wide range of nanofiltration membranes are investigated for the fractionation of a winery effluent and recovery of the polysaccharides of low molecular weight and of the polyphenols. Permeation experiments were carried out with three laboratory-made cellulose acetate membranes and two commercial membranes: NF270 membrane supplied by Filmtec Corp., Minneapolis, MN (USA) and ETNA01PP membrane supplied by Alfa Laval, Nakskov, Denmark. The five membranes were characterized by the rejection coefficients to a set of reference solutes and evaluated in terms of the rejection coefficients to polysaccharides, polyphenols, conductivity and total organic carbon. The rejection coefficients to polyphenols were overall lower than the ones to polysaccharides, meaning that the polyphenols permeate preferentially through all the membranes. Among these membranes, the NF270 membrane displayed the highest rejection coefficients for all parameters evaluated, with rejections in the order of 93.8% and 99% for polyphenols and polysaccharides, respectively. On the other hand, the ETNA01PP membrane presented the lowest rejection coefficients: around 27% to polyphenols and 72% to polysaccharides.     

Fouling of reverse osmosis membranes by hydrophilic organic matter: implications for water reuse

Effluent organic matter (EfOM) is suspected as a major cause of fouling of reverse osmosis (RO) membranes in advanced wastewater reclamation. Among the main constituents in EfOM, polysaccharides are the most ubiquitous. The influence of solution chemistry and hydrodynamics on RO membrane fouling with alginate — a model for polysaccharides in secondary wastewater effluent — was systematically investigated. Results of fouling runs with alginate demonstrate that RO membrane fouling increases with decreasing pH, increasing ionic strength, and addition of calcium ions. At fixed solution ionic strength and pH, the presence of divalent calcium ions, at concentrations typical of those found in secondary wastewater effluent, had a dramatic effect on membrane fouling. However, for similar concentrations of divalent magnesium ions, fouling was negligible. The severe fouling in the presence of calcium is attributed to the formation of a thick, dense alginate gel layer on the membrane surface via calcium-alginate complexation and crosslinking (bridging) of alginate macromolecules by calcium. In addition to solution chemistry, hydrodynamic operating conditions — initial permeate flux and crossflow velocity — were also shown to influence RO membrane fouling with alginate.     

Antioxidative Dietary Compounds Modulate Gene Expression Associated with Apoptosis,DNA Repair,Inhibition of Cell Proliferation and Migration

Many dietary compounds are known to have health benefits owing to their antioxidative and anti-inflammatory properties. To determine the molecular mechanism of these food-derived compounds, we analyzed their effect on various genes related to cell apoptosis, DNA damage and repair, oxidation and inflammation using in vitro cell culture assays. This review further tests the hypothesis proposed previously that downstream products of COX-2 (cyclooxygenase-2) called electrophilic oxo-derivatives induce antioxidant responsive elements (ARE), which leads to cell proliferation under antioxidative conditions. Our findings support this hypothesis and show that cell proliferation was inhibited when COX-2 was down-regulated by polyphenols and polysaccharides. Flattened macrophage morphology was also observed following the induction of cytokine production by polysaccharides extracted from viili, a traditional Nordic fermented dairy product. Coix lacryma-jobi (coix) polysaccharides were found to reduce mitochondrial membrane potential and induce caspase-3- and 9-mediated apoptosis. In contrast, polyphenols from blueberries were involved in the ultraviolet-activated p53/Gadd45/MDM2 DNA repair system by restoring the cell membrane potential. Inhibition of hypoxia-inducible factor-1 by saponin extracts of ginsenoside (Ginsen) and Gynostemma and inhibition of S100A4 by coix polysaccharides inhibited cancer cell migration and invasion. These observations suggest that antioxidants and changes in cell membrane potential are the major driving forces that transfer signals through the cell membrane into the cytosol and nucleus, triggering gene expression, changes in cell proliferation and the induction of apoptosis or DNA repair.     

序批式膜生物反应器处理生活污水的特性

研究了中试规模序批式膜生物反应器处理生活污水的特性.发现其对COD_Cr、NH₃-N及TN的去除效果可分别达到95.0%、96.3%及38.0%;过膜阻力增加率为1.032 kPa•m^-1.TN去除率偏低的主要原因在于缺少搅拌装置,在静置阶段时,污泥大部分沉积在反应器底部（系统运行期间30 min沉降比均低于40%）,从而使反硝化细菌不能充分与水溶液中的NO_x-N接触.采用空间排阻液相色谱法对混合液及膜污染物进行分子量分布测定,发现大量大分子物质在反应器内、膜面及膜孔内积累,相对分子质量大于10⁴的有机物分别占64.0%、38.0%.经过物理及化学清洗,膜通量恢复了73.4%,多糖含量为清洗前的30.4%,说明多糖是造成不可逆污染的主要物质.     

Effect of polysaccharides on the hydration of cement paste at early ages

This work deals with the relative efficiency of polysaccharides and their influence on cement hydration. Several parameters such as the structure, concentration, average molecular weight, and soluble fraction value of polysaccharides were examined. Cement hydration was monitored by isothermal calorimetry, thermogravimetry (TGA), and Fourier transform infrared (FTIR) spectroscopy. Results clearly show that retardation increases with higher polysaccharide-to-cement weight ratio (P/C). Low-molecular-weight starch showed enhanced retarding effect on the hydration of cement. The retardation effect of polysaccharides is also dependent on the composition of cement.