太湖梅梁湾有机污染物对纤细裸藻（Euglena gracilis）的遗传毒性效应

采用GC-MS方法分析了太湖梅梁湾水样的主要有机污染物成分和含量,共检测出15种目标化合物,表明该区域水体已经受到有机物污染;纤细裸藻(Euglena gracilis)在低浓度浓缩水样处理下(1倍组)生长无显著影响,叶绿素a、b含量和类胡萝卜素含量比对照组显著增加,而高浓度下(5倍和10倍组)生长明显受到抑制,叶绿素a和类胡萝卜素含量呈下降趋势;抗氧化酶系统中SOD和POD活性呈上升趋势,显示有机污染物胁迫可诱导抗氧化酶活性;彗星试验中,Olive尾矩和尾动量增加,纤细裸藻细胞DNA损伤程度随着太湖水样污染物浓度增加而加重,呈现出明显的剂量-效应关系,提示太湖梅梁湾水样具有潜在致突变性.结果表明,慧星试验和SOD活性试验结合使用在水环境中的遗传毒性监测方面具有较大的应用价值,适合作为水体有机污染监测的生物标志物.     

油田硫酸盐还原菌快速定量检测方法

现有油田废水中硫酸盐还原菌检测周期长、检测费用较高,本研究应用聚合酶链式反应(PCR)技术与倍比稀释法(MPN)相结合的DSR-MPN-PCR法,对硫酸盐还原菌进行快速定量检测.从废水中制备了直接用于PCR扩增的菌液,保证了定量准确性;建立以硫酸盐还原菌亚硫酸盐还原酶基因(Dsr)为靶位点的通用探针DSR1F和DSR5R的反应体系和扩增条件.结果表明,该方法检测灵敏度明显比液体稀释培养法高2个数量级,真实地表征了废水中实际的SRB菌数量,整个操作过程需要3～4　h,检测结果非常稳定,降低了检测费用,可以在生产中应用.     

两种兽药添加剂对蚯蚓的DNA损伤及其联合效应

采用土壤中的指示生物赤子爱胜蚓（Eisenia foetida）作为受试生物,研究了两种兽药添加剂四环素和金霉素对赤子爱胜蚓的急性毒性.结果表明：滤纸接触法染毒48h后,这两种兽药添加剂在所设最大受试剂量内没有引起蚯蚓死亡,半致死浓度LC50〉3.98×10^-2mg·cm^-2.应用彗星试验检测蚯蚓体腔细胞的DNA损...     

Assessment of source water contamination by estrogenic disrupting compounds in China

Detection of estrogenic disrupting compounds (EDCs) in drinking waters around China has led to rising concerns about health risks associated with these compounds. There is, however, a paucity of studies on the occurrence and identification of the main compounds responsible for this pollution in the source waters. To fill this void, we screened estrogenic activities of 23 source water samples from six main river systems in China, using a recombinant two-hybrid yeast assay. All sample extracts induced significant estrogenic activity, with E2 equivalents (EEQ) of raw water ranging from 0.08 to 2.40 ng/L. Additionally, 16 samples were selected for chemical analysis by gas chromatography-mass spectrometry. The EDCs of most concern, including estrone (E1), 17βup-estradiol (E2), 17αup-ethinylestradiol (EE2), estriol (E3), diethylstilbestrol (DES), estradiol valerate (EV), 4-t-octylphenol (4-t-OP), 4-nonylphenols (4-NP) and bisphenol A (BPA), were determined at concentrations of up to 2.98, 1.07, 2.67, 4.37, 2.52, 1.96, 89.52, 280.19 and 710.65 ng/L, respectively. Causality analysis, involving comparison of EEQ values from yeast assay and chemical analysis identified E2, EE2 and 4-NP as the main responsible compounds, accounting for the whole estrogenic activities (39.74% to 96.68%). The proposed approach using both chemical analysis and yeast assay could be used for the identification and evaluation of EDCs in source waters of China.     

Cloning,expression, and functional identification of CaSWEET7 and CaSWEET15 genes in Canarium album北大核心CSCD

糖外排转运蛋白(sugars will eventually be exported transporters,SWEET)介导植物光合同化产物蔗糖的跨膜运输.以橄榄(Canarium album(Lour.)Raeusch.)果实为材料,通过气相色谱串联质谱(GC-MS)检测橄榄果实中糖组分及含量变化,利用RT-PCR技术克隆得到CaSWEET7和CaSWEET15基因开放阅读框(ORF)序列.结果表明:CaSWEET7和CaSWEET15基因ORF全长分别为774 bp和951 bp,分别编码长度为257个和316个氨基酸残基,具有2个MtN3_slv结构域;进化树分析表明,CaSWEET7属于CladeⅡ,CaSWEET15属于CladeⅢ.实时荧光定量PCR(qRT-PCR)技术检测其在不同发育时期的果实中相对表达量变化,结果表明,随着果实发育,CaSWEET7和CaSWEET15表达量逐渐递增,且与果实发育蔗糖含量变化呈显著正相关(相关性系数分别为0.931和0.904,P<0.05);利用酵母功能互补证明CaSWEET7和CaSWEET15基因编码的蛋白具有转运蔗糖能力.本研究表明CaSWEET7和CaSWEET15基因可能在橄榄果实蔗糖积累中发挥作用.(图9表2参44)     

四膜虫彗星实验在环境水质检测中的应用

介绍四膜虫作为生物材料在彗星实验水质检测中的应用,探讨了将单细胞原生生物应用于彗星实验在环境水质检测、遗传毒性检测等方面的应用优势和发展前景。研究结果表明:过氧化氢浓度与细胞损伤之间呈现良好的剂量-效应关系,东湖水和长江水未造成四膜虫DNA的损伤,印染厂污水对细胞有严重的损伤作用,可能会影响正常的生态环境。     

In vitro toxic effects of heavy metals on fungal growth and phosphate-solubilising abilities of isolates obtained from Phragmites australis rhizosphere

In this research, we evaluated the toxic effect of metal ions on mycelial growth and phosphate-solubilising activity of soil-borne micromycetes isolated from the Phragmites australis rhizosphere using Pikovskaya-agar plates supplemented with four metal concentrations. The diameter growth rate (DGR) decreased as the metal concentration rise for all tested fungi. Trichoderma atroviride had the fastest growth rate (1.48?cm²?day^?1) and was the least susceptible to Al³⁺, Cd²⁺, Cr³⁺, Cu²⁺ and Pb²⁺ with a median effective concentration (MEC₅₀) of 12.19, 0.48, 4.51, 11.44 and 50.05?mM, respectively. Aspergillus japonicus was the most tolerant to Co²⁺, Ni²⁺ and Zn²⁺, with MEC₅₀ values of 3.36, 1.095 and 2.34?mM, respectively. Penicillium italicum was the most tolerant to Cr6⁺ (MEC₅₀?=?0.677?mM). The ability to solubilise phosphate remained, despite the decrease in the DGR, and P. italicum and Penicillium dipodomyicola had the highest Phosphate Solubilisation Indexes (PSIs) at 1.97 and 2.12, respectively. In particular, P. italicum recorded the highest PSI of all the studied isolates at 0.62?mM Cr³⁺ (PSI?=?4.74). A. japonicus and T. atroviride were the most tolerant isolates to all tested metals, which suggests that these isolates are promising candidates for further study with regard to mycoremediation and biofertilisation of metal-polluted soils.     

Glutathione S-transferase gene polymorphism,cigarette smoking and DNA damage

Several factors such as smoking habits, diet, occupational, and environmental exposure to chemical carcinogens influence the overall level of DNA damage. In 69 healthy adult volunteers’ polymorphisms of glutathione S-transferase (GST), an enzyme which participates in the metabolism of a broad range of carcinogens and endogenous compounds were determined. The level of DNA damage was assessed by comet assay and classified according to GSTT1/M1 genotype and smoking habits. GSTM1 null genotype was recognized in 48% of studied subjects and GSTT1 null genotype in only two cases (3%). In subjects carrying GSTT1/M1 alleles a significantly lower degree of DNA damage, determined as % DNA in the comet's tail, than in null individuals was noted. However, the results obtained did not indicate that in studied subjects an elevated endogenous level of DNA damage may be significantly related to smoking habits.     

Genotoxic and cytotoxic in vitro evaluation of ivermectin and its formulation ivomec® on Aedes albopictus larvae (CCL-126™) cells

Genotoxic effects of ivermectin (IVM) and its commercial formulation ivomec® (IVM 1.0%) were studied on Aedes albopictus larvae (CCL-126?) cells by sister chromatid exchange (SCE) and single cell gel electrophoresis (SCGE) while cytotoxicity was determined by cell-cycle progression (CCP), proliferative rate index (PRI), mitotic index (MI), 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and neutral red (NR) endpoints within a 1–250 µg mL^?1 concentration range. While IVM and ivomec® did not markedly affect SCE frequencies, these agents induced DNA-strand breaks enhancing both slightly damaged and damaged cells at 25–50 and 5–50 µg mL^?1 IVM and ivomec®, respectively. Both compounds exerted a delay in CCP and reduction of PRI at 10 µg mL^?1. Cytotoxicity was observed at concentrations higher than 25 µg mL^?1. A marked reduction of about 98% and 94% of MI compared to controls was noted with 25 µg mL^?1 of IVM and ivomec®, respectively. NR and MTT assays revealed that both compounds induced a cell growth inhibition within the 1–250 µg mL^?1 concentration range. Data indicated that IVM and ivomec® exert both genotoxicity and cytotoxicity in insect cells in vitro, at least in A. albopictus larvae CCL-126? cells.     

Studies on the water extracts of medicinal plants grown in copper mining areas and their antioxidant effects

High copper (Cu) accumulation in medicinal plants might favor lipid peroxidation and hence affect antioxidant responses. This effect was studied by determining antioxidant activities in the water extracts of medicinal plants from Cu mining impact site and compared with control samples. Antioxidant activities of the extracted medicinal plants were assayed by measuring (1) total phenolic and flavonoid contents, (2) diphenyl-1-picrylhydrazyl (DPPH)^? free radical scavenging activity, and (3) inhibition capacities of lipid peroxidation. The total phenolic as well as total flavonoid contents of the mining impact samples and control samples are not significantly different. However, inhibition of lipid peroxidation capacities was significantly less (12–60%) for mining impact samples as reflected by the IC₅₀ values. These anomalies were attributed to high concentrations of Cu (2–4-fold higher) in mining impact samples as measured by inductively coupled plasma mass spectrometry. A positive correlation was observed between Cu levels and IC₅₀ values for the inhibition of lipid peroxidation for mining impact samples.