Cadmium uptake by a phytoplankton species in the presence of different inhibitors&

The uptake of cadmium by the Haptophyceae Hymenomonas elongata was studied as regards the energetic processes and Ca‐transport. For this purpose, experiments were carried out in the presence of an uncoupler of the phosphorylation : CCCP and of an inhibitor of calcium channels and also of Ca²⁺‐ATPase : verapamil. To reduce the number of assays, a factorial experimental design was used, in which all variables:— concentration of Cd in the medium—incubation time and—the presence of the inhibitor, are at two levels. In the absence of inhibitor, Cd uptake was found to vary as a function of metal concentration in the medium and of incubation time. CCCP significantly increased Cd uptake by H. elongata at sufficient incubation time. Therefore Cd uptake seemed linked to an energy‐dependent process, involving an ATPase. Verapamil immediately increased Cd uptake, implying an interaction between Cd and Ca.     

厌氧氨氧化颗粒污泥的长期保藏及快速活性恢复

在4℃且无基质的条件下,将厌氧氨氧化颗粒污泥保藏230 d之后进行活性恢复,探究添加葡萄糖和丙酸钠两种有机碳源对于快速活性恢复的影响.经过230 d的长期保藏,厌氧氨氧化菌活性为0.013 g·（g·d）^-1,仅为保藏前的6.02%,且平均粒径为135.05 μm,骤降至原来的38.23%,污泥解体、颜色发黑.在活性恢复阶段,R2和R3反应器分别添加葡萄糖和丙酸钠作为有机碳源,恢复结果显示,经过15 d的恢复,R1、R2和R3反应器的PN含量分别达到了126.30、188.86和168.82 mg·g^-1,厌氧氨氧化菌活性均有所提升,分别达到了0.145、0.185和0.126 g·（g·d）^-1,其中,添加葡萄糖作为有机碳源的R2反应器厌氧氨氧化菌活性最高,恢复到了保藏前的85.65%,且总氮去除率达到81.61%.第20d时,R1、R2和R3反应器中厌氧氨氧化颗粒污泥的粒径分别为289.81、359.66和314.37 μm,表明厌氧氨氧化颗粒污泥的长期保藏不是无法克服的难题,且在恢复阶段添加葡萄糖不仅可以有效提高EPS含量,促进颗粒生长和黏附,而且丰富了厌氧氨氧化的反应途径,使其在恢复阶段与其他细菌的底物竞争中占据优势,更快地恢复活性.     

湖泊沉积物中微生物群落对天然有机质输入的响应

全球气候变化和蓝藻水华暴发造成湖泊生源、陆源天然有机质（NOM）输入显著增加,以太湖藻型湖湾为例,考察沉积物中微生物群落的活性、组成及功能对不同浓度藻源有机质（POM）和陆源腐殖酸（HA）的响应特征.三维荧光分析显示POM化学多样性较高,包含易降解的类蛋白（50%）和难降解的类腐殖质组分（50%）,而类腐殖质占HA荧光组分的97%.两个月的微宇宙实验表明,对于同种NOM,沉积物中微生物矿化作用随NOM浓度升高而增强;但POM组中有机碳去除量显著高于同等浓度的HA组.胞外聚合物分析显示NOM输入有利于微生物分泌蛋白质和多糖,提高了微生物群落的聚集度和稳定性;酶活分析表明POM对脲酶、脱氢酶等有机物代谢酶的激发效应强于HA,形成了代谢更活跃的微生物群落.同时,NOM输入（尤其是POM）提高了微生物群落的物种多样性,增加了Proteobacteria和Bacteroidetes等参与有机物分解的菌群丰度,上调了与代谢相关的KEGG功能基因丰度.以上结果表明湖泊沉积物中微生物群落的活性和功能与NOM的来源和浓度有关.     

吸收协同高级氧化工艺处理低浓度含氰废气实验研究

以乙腈作为含氰废气的典型组分,考察吸收协同不同高级氧化体系下低浓度乙腈的去除效率以及产物分配情况.研究结果表明：UV/PS和VUV/PS体系均能有效吸收并降解乙腈,在60 min内其脱除效率近100%,且矿化率近80%或以上.主要原因是吸收液中的过硫酸盐（PS）可以在紫外光的激发下产生大量的HO^·和SO₄^·-,这些自由基可以促进乙腈和中间产物的氧化.同时实验还观察到乙腈中的氮元素主要被转化为NO₃^-和NH₄⁺,这说明乙腈的直接氧化和水解反应同时进行.NO₃^-的累积会竞争消耗反应体系中的自由基,这是其稳定性实验中乙腈矿化率下降的主要原因.此外,干扰离子Cl^-也会由于自由基的捕获作用抑制乙腈的降解.最后,根据产物的分析结果,提出了包含氧化与水解路径的乙腈总体降解反应途径.     

基于斑马鱼毒理基因组学的化学品测试技术研究进展

大量缺乏毒性信息的化学品最终进入环境水体,对人类及生态生物产生潜在的危害与风险。提高化学品生物毒性测试与评估技术的通量和效率,是实现毒害化学物质环境与生态健康风险防控的关键。作为一种可以实现高通量测试的脊椎动物模型,斑马鱼胚胎测试在化学品的毒性评估中应用广泛。随着组学技术的发展,毒理基因组学可有效提取毒害化学品致毒过程中干扰生物学通路的信息。这些机制信息可用于对单物质或复合污染物生物毒性的筛选和预测。本文综述了不同斑马鱼胚胎测试技术在化学品毒性筛选评估管理与水环境复合污染毒性监测中的发展和应用,详细介绍了一种新型斑马鱼胚胎简化转录组学技术的方法流程和优势,并探讨了综合斑马鱼胚胎毒性测试、行为分析和组学等不同测试技术在化学品毒性测试、环境监测与评价中的应用前景。     

Seasonal variations of transport pathways and potential sources of PM2.5 in Chengdu,China (2012–2013)

PM_2.5 in Chengdu showed clear seasonal and diurnal variation. 5, 5, 5 and 3 mean clusters are generated in spring, summer, autumn, and winter. Short-distance air masses are important pathways in Chengdu. Emissions within the Sichuan Basin contribute significantly to PM_2.5 pollution. Long-range transport from Southern Xinjiang is a dust invasion path to Chengdu. Seasonal pattern of transport pathways and potential sources of PM_2.5 in Chengdu during 2012–2013 were investigated based on hourly PM_2.5 data, backward trajectories, clustering analysis, potential source contribution function (PSCF), and concentration-weighted trajectory (CWT) method. The annual hourly mean PM_2.5 concentration in Chengdu was 97.4 mg·m^–3. 5, 5, 5 and 3 mean clusters were generated in four seasons, respectively. Short-distance air masses, which travelled within the Sichuan Basin with no specific source direction and relatively high PM_2.5 loadings (>80 mg·m^–3) appeared as important pathways in all seasons. These short pathways indicated that emissions from both local and surrounding regions of Chengdu contributed significantly to PM_2.5 pollution. The cities in southern Chengdu were major potential sources with PSCF>0.6 and CWT>90 mg·m^–3. The northeastern pathway prevailed throughout the year with higher frequency in autumn and winter and lower frequency in spring and summer. In spring, long-range transport from southern Xinjiang was a representative dust invasion path to Chengdu, and the CWT values along the path were 30-60 mg·m^–3. Long-range transport was also observed in autumn from southeastern Xinjiang along a northwesterly pathway, and in winter from the Tibetan Plateau along a westerly pathway. In summer, the potential source regions of Chengdu were smaller than those in other seasons, and no long-range transport pathway was observed. Results of PSCF and CWT indicated that regions in Qinghai and Tibet contributed to PM_2.5 pollution in Chengdu as well, and their CWT values increased to above 30 mg·m^-3 in winter.     

杆状病毒在昆虫宿主内的感染途径及其复制

昆虫病毒的发现始于１６世纪,但直到本世纪５０年代,伴随着电子显微镜的发明,昆虫病毒学的研究才得到飞速发展．近年来,昆虫病毒学的研究已引起人们的高度重视,主要是因为：１．杆状病毒可做为载体,以表达外源基因;２．做为杀虫剂,可有效地控制农业病虫害的发生,...     

应用EGSB反应器处理五氯苯酚废水

对EGSB反应器处理五氯苯酚(PCP)废水的运行条件以及PCP的降解途径作了研究.结果表明,在进水PCP浓度为95mg/L,COD浓度为5000mg/L时,出水回流比为90,水力停留时间(HRT)为16h的条件下,出水PCP和COD浓度达到排放要求(PCP<0.1mg/L,COD<100mg/L),反应器PCP容积负荷142.5g/(m³·d),有机容积负荷为COD7.5kg/(m³·d).PCP在EGSB反应器中主要脱氯产物是2,3,4,5-TeCP,2,3,5-TCP以及2,3,4,6-TeCP,表明PCP主要通过邻位脱氯产生2,3,4,5-TeCP,再脱氯产生2,3,5-TCP,部分PCP首先间位脱氯产生2,3,4,6-TeCP.     

宁夏黄土丘陵区农田土壤细菌海拔分布特征

研究农田土壤微生物多样性、结构与功能的海拔分布特征及其影响因子,对保护农田生态系统生物多样性具有重要意义.利用高通量测序技术对宁夏黄土丘陵区农田土壤细菌多样性、群落结构和代谢功能沿海拔分布特征及其对土壤理化性质的响应进行分析.结果表明:①土壤细菌Alpha多样性指数与海拔呈显著负相关,沿海拔呈现先降低再略升高的变化趋势.②变形菌（Proteobacteria）、放线菌（Actinobacteria）和酸杆菌（Acidobacteria）等7个菌门为优势菌群,其中5个菌群在海拔间具有极显著性差异.③二级分类水平上包括膜运输、碳水化合物代谢和氨基酸代谢等36个细菌代谢功能,其中22个在不同海拔间具有显著性差异,12个具有极显著性差异.④Pearson相关分析表明,土壤含水量、容重、pH和碳氮比对细菌Alpha多样性影响最为显著,总有机碳、全氮和全磷等土壤养分对细菌Beta多样性具有显著影响.⑤Mantel分析表明,门水平细菌群落结构受土壤含水量、总有机碳和碳氮比影响,细菌代谢功能与土壤pH、总有机碳、全氮、全磷和碳氮比均有显著相关性.方差分解分析显示土壤含水量对群落结构解释度最高,pH对代谢功能解释度最高.由此可知,土壤含水量和pH是影响宁夏黄土丘陵区农田土壤细菌多样性、群落组成和代谢功能的主要土壤因子.     

睾丸酮丛毛单胞菌对喹啉的微生物降解途径的研究

从油制气废水的活性污泥中分离得到一株可以在好氧条件下利用喹啉作为唯一碳源和能源的睾丸酮丛毛单胞菌 (Co mamonastestosteroni,编号为Q10 ) .浓度为 2 5 0mg L的喹啉可被该菌完全降解 ,TOC去除率为 70 % .实验结果表明喹啉首先降解为 1H— 2 氧喹啉 ,然后继续转化为 6 羟基— 1H— 2 氧喹啉、5 ,6 二羟基— 1H— 2 氧喹啉和 5 羟基— 6 (2 羧基乙烯基 )—1H— 2 吡啶酮 ,由此提出该菌降解喹啉的一种可能途径 .样品中还发现少量的 8 羟基— 1H— 2 氧喹啉 ,表明菌Q10 对喹啉的降解可能是通过以一种途径为主的多种途径进行的 .