哌嗪基[口恶]唑烷酮类衍生物的合成及其体外抗菌活性研究

以S-环氧氯丙烷和3,4-二氟硝基苯为原料,设计并合成了12个哌嗪取代[口恶]唑烷酮类化合物,其结构均经高分辨1HNMR和MS确认。以利奈唑胺为参照物,对合成的化合物进行了金黄色葡萄球菌、链球菌和大肠杆菌的体外抗菌实验,结果表明,合成的化合物有一定抗菌活性,但活性均明显低于利奈唑胺。     

橙皮中橙皮苷的微波法提取工艺研究

采用微波法探讨橙皮中提取物的抗氧化效果,通过正交实验对提取橙皮苷的工艺条件进行优化。结果表明:固液比1∶20,80%的乙醇水溶液为溶剂、在微波火力80 W下提取时间60s时清除率最高。     

盐度入侵城市污水处理厂对淡水活性污泥的毒性抑制

盐度入侵城市污水处理厂改变了活性污泥的胞外渗透压环境,影响生物系统的生物活性和污染物降解能力。采用MUCT工艺处理真实生活污水,模拟了盐度入侵对系统处理效率的影响。并结合污染降解动力学和抑制动力学建立了盐度抑制模型,系统地评测了盐度对活性污泥功能性微生物的毒性抑制。结果表明,盐度入侵造成了功能性微生物的活性损失,干扰了正常的污水处理能力。毒性抑制显著地降低了好氧微生物的呼吸作用,以此作为毒性评估的依据会造成对抑制作用的高估。而以底物降解速率评估盐度毒性抑制可以很好地指示污水处理效率。盐度对有机物降解异养菌、硝化菌和反硝化菌抑制的IC₅₀值分别是20.64 g·L^-1、11.61 g·L^-1、10.88 g·L^-1。     

提取方法和溶剂对石榴皮中抑菌成分提取的影响

探讨了石榴皮中抑菌成分的提取方法.分别以水、40％乙醇、60％乙醇和丙酮作为溶剂,采用微波提取法、超声波提取法、加热回流提取法对石榴皮中抑菌成分进行提取;并考察提取物对大肠杆菌和金黄色葡萄球菌的抑菌作用.结果表明:以60％乙醇作为溶剂时,微波提取物和超声波提取物的抑菌活性比加热回流提取物高,且具有提取时间短、效率高等特...     

H_4SiW_（12）O_（40）/TiO_2-ZrO_2的制备及光催化降解甲基橙的研究

采用浸渍法制备了H4SiW12O40/TiO2-ZrO2光催化剂,以光催化降解染料废水甲基橙为探针反应,探讨了催化剂投加量、溶液pH值对光催化降解效果的影响以及催化剂的重复使用性。结果表明,H4SiW12O40/TiO2-ZrO2催化剂具有更优越的光催化性能,当催化剂的用量为1.8 g/L,甲基橙溶液初始浓度为10 mg/L,pH=4时,反应4 h后甲基橙的降解率可达90%以上。     

毕赤酵母产重组木聚糖酶发酵条件的优化及其酶学性质

目的优化毕赤酵母工程菌GS115/xyn11A产重组木聚糖酶的发酵条件,并检测其酶学性质。方法采用单因素试验和L(934)正交试验考察摇瓶发酵条件下培养基起始pH值、诱导剂甲醇添加量、诱导温度及诱导时间对产酶活性的影响;并分析重组木聚糖酶的酶学性质。结果影响重组毕赤酵母产酶的因素重要性依次为:培养基起始pH值>诱导时间>诱导温度>甲醇添加量,重组酵母产酶最佳条件为:起始pH值7.5,甲醇添加量1.5%,32℃诱导96 h,在此条件下进行诱导表达重组木聚糖酶的酶活性可达228.35 IU/ml;酶的最适反应温度为50℃,最适反应pH值为5.5,在低于40℃和pH 4.5～7.5的范围内较稳定。结论优化了毕赤酵母产重组木聚糖酶的发酵条件,为木聚糖酶的工业化生产及应用提供了依据。     

3-甲基-5-苯基-2-(3-氟苯基)吗啉盐酸盐合成及其抗实验性抑郁活性

1-(3-氟苯)-2-溴-1-丙酮在非质子极性溶剂中经胺化、环合反应,最后酸化,得到3-甲基-5-苯基-2-(3-氟基苯基)吗啉盐酸盐,总收率为70.6%。目标化合物结构经IR、1H NMR、MS测试技术确证。参照Porsolt法,使用小鼠强迫游泳药理实验模型,对所合成的化合物进行抗实验性抑郁药理活性研究。结果显示,此化合物具有良好的抗抑郁活性,值得进一步研究。     

丹皮酚合成过程中抑菌活性的变化研究

研究了在丹皮酚的合成过程中,原料间苯二酚、中间产物2,4-二羟基苯乙酮及主产物丹皮酚对11种植物病原真菌的抑菌活性,并通过抑菌活性的变化来推测影响抑菌活性的主要官能团.结果表明:0.5g·L-1的2,4-二羟基苯乙酮对11种真菌的抑菌率大于或等于同浓度丹皮酚的抑菌率,两者均远远大于同浓度间苯二酚的抑菌率.由此可推测,酚类分子中乙酰基的引入对抑菌活性起到了非常重要的作用,而酚羟基的甲基化的作用却并不显著.该结论对寻求具有更高抑菌活性的酚类衍生物有着非常重要的意义.     

Study on the use of NADH fluorescence measurements for monitoring wastewater treatment systems

Fluorescence measurement of intracellular nicotinamide adenine dinucleotide (NADH) provides information about the physiological response of microbes towards changing conditions in their environment and has been suggested to be useful for the control of wastewater treatment plants. In this study, the practical usefulness of such measurements was evaluated from batch experiments with a commercially available NADH sensor in a bench scale reactor. The sensor was linear in the NADH concentration, robust, almost maintenance free, and hardly sensitive to floc size distribution. Measured fluorescence intensity proved to depend strongly on the concentration of active heterotrophic biomass. The NADH level was supposed to be dependent on the ratio of electron donor/electron acceptor availability inside the cells; however, neither acetate nor ammonium addition was reflected by the measurement signal.A jump wise NADH signal change was observed at complete oxygen or nitrate depletion as also reflected by bends in the redox curve. In the near zero concentration ranges of oxygen and nitrate (0.1-0.5mg/l) the signal changes only slightly in the opposite direction to the redox trend.     

Biofilm in the sediment phase of a sanitary gravity sewer

Microbial activity of the sediment phase in a 1.5-km-long concrete sewer section with a cement pipe in a 540-mm diameter was investigated in this paper. SEM examinations and elementary composition analyses of the sediment samples have identified the presence of a biofilm layer at the sediment surface. Bacterial counting results with a DNA-staining technique have revealed that the amount of bacteria in this layer was 2.1 x 10(11)cellg(-1) dry wt, which is close to that of activated sludge. ATP content in the sewer biofilm was found relatively high, demonstrating that the sewer biofilm is active. Throughout the entire 1.5-km sewer section, the biofilm activity was maintained at almost the same level. Lab-scale sediment oxygen uptake flux (SOUF) tests showed that the shear flow velocity above the sediment phase linearly increases the SOUF, which of the potential value was determined to be 32gO(2)m(-2) day(-1) at an estimated shear flow velocity of 0.055ms(-1) at 25 degrees C in the sewer line, provided that the mean flow velocity was 1.5ms(-1), and the mean water depth was 220mm. Such a high SOUF value further endorsed the existence of the active sewer biofilm.