磁场对固定化紫色非硫光合细菌脱氢酶影响的研究

研究磁场作用对固定化紫色非硫光合细菌（ＰＳＢ）脱氢酶活力的影响，选出可产生最佳磁生物效应的磁场值，并证明磁场作用一定累积效应，实验结果表明在最佳磁场作用下，最适温度为３０－４０℃，最适ｐＨ值为８，脱氢酶活力可提高３０％左右，有良好热稳定性和ｐＨ稳定性。在４℃冰箱保存４５至２１０ｄ，磁场对脱氢酶活力影响基本稳定，可保持提高２０％。磁场对菌液中加某些金属离子（Ｆｅ＾２＋、Ｍｎ＾２＋、Ｚｎ＾２＋）ｂｎ     

戊二醛对紫色非硫光合细菌脱氢酶活力的影响

探讨微生物细胞对戊二醛毒性的耐受能力及应用条件的适宜范围,可为废水处理中固定化细胞的应用提供实验基础和理论依据。以紫色非硫光合细菌（PSB）为例,直接用戊二醛作用于细胞,在不同pH值、温度、戊二醛浓度、反应时间等条件下研究戊二醛对PSB脱氢酶活力的影响。结果表明：戊二醛对PSB脱氢酶活力影响的主要限制因素为戊二醛浓度和反应时间。当戊二醛浓度为0.5～1.0％,反应时间为1～2h时,PSB脱氢酶活力回收可达83％以上;PSB细胞经戊二醛处理后,热稳定性增强,pH稳定性无明显变化;并比较出热带假丝酵母菌和PSB对戊二醛的毒性耐受能力大于大肠埃希氏杆菌和芽孢杆菌yol。     

IC反应器处理啤酒废水的效能及其微生物群落动态分析

在35℃下连续运行内循环厌氧反应器(IC),通过不断提高进水容积负荷,研究不同运行负荷下反应器处理模拟啤酒废水的运行情况,并探讨微生物的种群结构与其活性变化之间的相互关系.IC反应器效能分析表明其最大进水容积负荷(以COD计)可达20 kg.(m3.d)-1,COD去除率为85%以上,最大比产甲烷活性(以VSS计)可达210 mL.(g.d)-1;污泥脱氢酶活性与细菌DGGE图谱表明反应器中脱氢酶活性的变化趋势与细菌DGGE条带总光强度的变化趋势一致,DGGE图谱中细菌条带的总光密度值可作为厌氧体系中生物量的一个参考指标;辅酶F420与古细菌DGGE分析表明,污泥中辅酶F420含量与甲烷鬃菌属(Methanosaeta sp.)的相对丰度有一定的相互联系,在低负荷条件下甲烷八叠球菌属(Methanosarcina mazei)优势地位比较显著,随着负荷的提高,甲烷鬃菌属(Methanosaeta sp.)优势地位逐渐显著,且辅酶F420含量随之升高,当最大负荷为20kg.(m3.d)-1时,辅酶F420的含量(以VSS计)达到0.16μmol.g-1,而此时甲烷鬃菌属(Methanosaeta sp.)占据尤为明显的优势地位;聚类分析(UPGAMA)和Shannon指数也表明在不同反应负荷下,微生物的群落结构变化明显.     

Effects of Cd2+ and Pb2+ on the substrate biofilms in the integrated vertical-flow constructed wetland

The effects of single Cd~(2+)and Pb~(2+),and combined Cd~(2+)and Pb~(2+)on dehydrogenase activity and polysaccharide content of the substrate biofilms in the integrated vertical-flow constructed wetland(IVCW)were studied.Dehydrogenase activities decreased linearly with the increasing concentrations of Cd~(2+)and Pb~(2+)at different times(6,24,72,and 120 h).The activities at both 6 and 24 h were significantly higher than that at 72 and 120 h in the case of single and combined treatments.The single Cd~(2+)...     

啶酰菌胺在斑马鱼体内的富集特性及其对SDH和复合物Ⅱ活性的抑制

为进一步探索啶酰菌胺对水生生物的毒性,选择斑马鱼为供试生物,采用半静态法,研究了啶酰菌胺在斑马鱼体内的富集与消除规律及对其肝脏和鳃的毒性作用。结果表明,斑马鱼暴露于0.08、0.32 mg·L~(-1)中,14 d后均达到富集平衡,28 d生物富集系数(BCF_(28 d))分别为35.50和36.72。在0.16、0.32 mg·L~(-1)浓度下,斑马鱼的比肝重(HSI)和比鳃重(BSI)均明显高于对照组,而肝脏和鳃中琥珀酸脱氢酶(SDH)和线粒体呼吸链复合物II活性均明显低于对照组,浓度低于0.08 mg·L~(-1)时,对斑马鱼无明显影响。由此可知,啶酰菌胺对斑马鱼为中等富集性,并对其肝脏和鳃有一定毒性作用。     

SBR法处理还原段DSD酸废水脱氢酶活性的研究

对SBR法处理还原段DSD酸生产废水处理中污泥活性进行了分析。脱氢酶活性能及时准确地反映污泥活性变化,预知水质波动。在整个代谢过程中,总脱氢酶活性(Dt)和基质脱氢酶活性(Ds)变化规律相似;当了解体系大体情况时,Dt可代替Ds反映污泥活性变化。Dt与可降解COD浓度之间较好的服从莫诺关系式,Dt具有生化反应速率的意义。研究表明,在温度为30℃,葡萄糖投加量为250mg/L,有机负荷为0.6kg(/kg·d),pH值为7的条件下,脱氢酶活性最高。     

In vivo and in vitro metabolism of tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), by the freshwater planarian, Dugesia japonica

Cigarette smoke is a risk factor for human health, and many studies were conducted to investigate its adverse effects on humans and other mammals. However, since large amounts of cigarette products are produced and consumed, it is possible that tobacco chemicals can end up in aquatic environments through several routes, thus influencing aquatic organisms. In this study, the presence of tobacco-specific nitrosamine (TSNA), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), in aquatic environment was demonstrated. Since toxic effects on and distribution patterns of tobacco chemicals in aquatic organisms were rarely studied, after results of an acute toxicity pretest were obtained, experiment was conducted to investigate the bioaccumulation pattern of NNK and distribution patterns of its metabolites, mainly 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), in NNK-treated freshwater planarians, Dugesia japonica. Results from in vivo and in vitro studies showed that NNK was readily converted to NNAL through the carbonyl reduction in bodies of NNK-treated planarians. Tissue concentrations of both chemicals increased in time- and dose-dependent manners. Furthermore, we examined the end products of NNK/NNAL α-hydroxylation in NNK-treated planarians, but only 1-(3-pyridyl)-1,4-butanediol was detected, suggesting that NNK metabolism in planarians partially differs from that in mammalian systems. This is the first report on NNK metabolism in an aquatic organism and can be used as a foundation for developing freshwater planarians as a new in vivo model for the study of NNK toxicology in the future.     

餐厨垃圾与剩余污泥混合消化产沼气协同效应

在(35±0.2)℃温度下,以餐厨垃圾和剩余污泥为原料,设置餐厨垃圾和剩余污泥混合比例(VS)分别为1∶0、2∶1、1∶1、1∶2和0∶1,研究其单独消化与混合消化的系统性能、产甲烷潜力及脱氢酶活性和F420浓度变化。结果表明,混合消化提高了系统稳定性,与餐厨垃圾单独消化相比,添加剩余污泥能调节pH、氨氮浓度和VFA浓度,缩短产气周期;与剩余污泥单独消化相比,添加餐厨垃圾能显著提高沼气产量。混合比例为1∶1组混合消化产甲烷潜力最佳,消化作用的协同效应最为明显,沼气和甲烷产量分别达358.2 mL/g VS和224.1 mL/g VS,较餐厨垃圾和污泥单独消化估计值分别提高了23.09%和36.80%。1∶1混合消化组脱氢酶活性最高达437.33 TFμg/(mL·h),比餐厨垃圾和剩余污泥单独消化分别提高93.60%和40.69%,辅酶F420浓度最高为1.718μmol/L,分别提高17.3%和100.7%。     

二氧化硫对大鼠肺泡细胞和肺泡灌洗液的生化效应

研究了二氧化硫(SO2)对大鼠支气管肺泡灌洗细胞和肺泡灌洗液(BALF)的生化指标的影响。结果表明，吸入SO2后大鼠BALF中肺泡巨噬细胞数量增加、但比例减少，中性粒细胞和淋巴细胞数量和比例均增加，并存在剂量一效应关系；熏气后BALF的pH下降、蛋白质含量和肺通透指数升高，BALF中酸性磷酸酶、碱性磷酸酶和乳酸脱氢酶活性升高，脂质过氧化水平提高：这些细胞和生物化学指标的改变从不同的方面反映了SO2可引起大鼠肺组织和肺泡细胞的结构和功能的损伤。     

不同负荷下生物膜脱落与载体生物膜生物特性的相互影响

为探究不同负荷下生物膜的脱落特性,对试验过程中生物膜脱落量及载体上生物膜生物特性进行了研究.结果表明:生物膜脱落量随运行时间延长而增大;有机负荷对生物膜脱落量的影响不同,负荷高脱落量大.紧密结合胞外聚合物(TB-EPS)是生物膜胞外聚合物(EPS)的主要组成部分,生物膜EPS量随负荷的增大而增大;EPS中多糖含量越高,生物膜脱落量越小.系统中pH值逐渐下降并抑制生物膜活性,生物膜脱落量随着脱氢酶活性的下降而增加,载体上生物膜脱氢酶活性也会随着生物膜脱落量的增加而下降.生物膜脱落过程中,生物膜微型动物多度、物种数减少,物种多样性水平随着运行时间延长而降低;有机负荷较高,生物膜微型动物多样性较高,物种稳定性指数WS较高而多样性稳定性指数WH较低,但其生物膜脱落量大.因子分析揭示了不同负荷下生物膜脱落与生物膜特性的相互关系,与生物膜脱落紧密相关的因子依次为生物膜组成与活性因子、生物因子、负荷因子等.生物膜脱落与载体上附着生物膜相互作用、相互影响.