PFU微型生物群落水质鉴别及群落参数变化模式的研究

基于ＰＦＵ微型生物群落参数调查数据，对湖北省汉江两条污染带１１个站 和湖南常德市水系１５个站点所属水质组别进行了综合分析研究。所得典型鉴别函数能够对水质组别作出有效的鉴别，分类函数对站点的水质组别分类正确率达到９６％；群落参数对化学综合污染指数的响应不呈简单的线性关系，群落的变化存在一定模式。     

A comparison of hydrocarbons emission from engine running 85# gasoline and M-100 methanol fuel

Increasing global interest in methanoi fuel has led us to investigate the exhaust emissionsof its engine. Analysis of its inorganic and organic emissions. such as CO. NO_x and hydrocarbons(total HC) have been widely reported. This paper presents an analysis of more than 20 kinds ofhydrocarbons in the emissions obtained from a spark-ignition Shanghai car running 85^# gasoline anda comparison with emission from a Santana test car running M-100 methanol fuel. A set ofenrichment method has also been described. Test results show that at the current stage of methanolengine development the concentration of individual hydrocarbon including some poisonous substancesis lower than those of normal gasoline engine.     

降解五氯酚厌氧生物反应器微生物种群结构的分子特性研究

采用PCR—DGGE技术，对降解PCP厌氧生物反应器污泥颗粒化过程微生物种群结构的时空分布变化特性进行了初步研究．结果表明，随着PCP负荷增加与污泥的颗粒化，污泥真细菌、古细菌组成均发生明显变化．当反应器稳定运行时，反应器内上下层污泥微生物种群结构组成相似，真细菌相似性Cs在71．4～77．6之间，古细菌Cs在70．4～76．7之间．反应器一旦受污染物负荷冲击干扰，反应器上下层污泥真细菌组成相似性Cs降至43．3，古细菌降至35．2．测序表明，颗粒污泥中存在不可培养的脱氯细菌，优势产甲烷细菌为Methanosaeta concilii、Methanobacterium sp．、Methanobrevibacter sp．和Methanothfix soehngenii．     

镉胁迫下大豆中镉的分布状况及其籽粒品质

溶液培养中0.5μmol·L-1镉胁迫浓度下,大豆表现出轻微受害症状,籽粒减产25 . 7%,而籽粒中粗脂肪和粗蛋白含量变化不大.镉在大豆中的积累分布状况为根>叶>籽>油,比例为32.100:1.690:1.000:0.003.大豆籽粒含镉4.89mg/kg,超过了国家环境标准规定的最高容许量.而大豆粗脂肪中含镉仅0.015mg/kg,远低于国家食品环境卫生标准.豆粕中含镉6.17mg/kg,表明大豆籽粒中的镉主要存在于粗蛋白和淀粉中.     

多种染料的微生物脱色研究

从印染、毛纺等废水处理场的生物膜和活性污泥中分离到13株对36种染料有脱色能力的细菌。其中三株转化单胞菌D_(32),D_(33),D_4分别对29种染料有良好的脱色作用,其完整细胞对单一染料的脱色活力达2.6mg·g~(-1)(细胞湿重)·h~(-1)。对脱色反应的条件和机理进行了初探。     

Renatal diagnosis of mosaic tetrasomy 12p/trisomy 12p by fluorescent in situ hybridization in amniotic fluid cells: A case report of pallister–killian syndrome

A prenatally detected case of a rare mosaic tetrasomy 12p/trisomy 12p is reported, presenting as the well-known accessory isochromosome 12p and a supernumerary single 12p marker in 17/24 and 6/24 clones of cultured amniotic fluid cells, respectively. The chromosomal nature of both marker chromosomes was investigated in cultured amniotic fluid cells by fluorescent in situ hybridization with various probes: the 12-centromeric probes pa12H8 and D12Z3, a whole chromosome 12 paint, and the chromosome 12p-specific paint M28. DNA analysis revealed a maternal origin of the extra 12p material. After counselling, the parents requested termination of pregnancy. Inspection and autopsy of the fetus revealed many of the dysmorphisms and internal structural abnormalities of the Pallister–Killian syndrome.     

基于原代培养背角无齿蚌鳃细胞的镉毒性效应评价

为了探究淡水贝类背角无齿蚌鳃细胞的原代培养途径，并阐释其在评价水体Cd²⁺毒性效应上的潜力，本研究比较了不同酶分解方法（链霉蛋白酶、胰蛋白酶）的鳃细胞存活率差异，并分析了L-15培养基中不同血清浓度（10% FBS、20% FBS）对鳃细胞存活率的影响，细胞置于20℃生化培养箱中培养.进而根据Cd²⁺对鳃细胞的LC₂₅值设定0.0625、0.125、0.25、0.5和1.0 mg·L^-1 5个Cd²⁺理论浓度梯度，对原代培养的鳃细胞进行24 h暴露，分析了细胞活力、总超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和酸性磷酸酶（AcP）的变化特征.结果表明：0.025%链霉蛋白酶在4℃分解16 h的鳃细胞存活率为98.2%±0.2%，显著高于0.25%胰蛋白酶在26℃分解30 min的89.4%±3.5%鳃细胞存活率（p<0.05）；L15培养基加入10% FBS的细胞存活率总体显著高于添加20% FBS的细胞存活率（p<0.05）.在上述较佳的分解和血清浓度组合条件下，细胞培养120 h后，其存活率仍高达90.1%±4.7%.鳃细胞活力随着Cd²⁺浓度的增加而降低，两者之间呈显著的线性负相关（p<0.05）；随着Cd²⁺浓度的增加，SOD和AcP含量总体增加，而CAT含量呈现出"诱导-抑制"的变化趋势.本研究初步建立了较为适宜的背角无齿蚌鳃细胞的原代培养方法，并揭示了其原代培养鳃细胞的细胞活力及SOD、CAT、AcP水平，具有作为评价水环境Cd²⁺毒性/污染的生物指标的潜力.     

Detection of low-grade mosaicism in fetal cells isolated from maternal blood

Recovering and analysing fetal erythrocytes from maternal blood is being pursued for non-invasive prenatal genetic diagnosis. We report the observation of 46, XY/47, XXY mosaicism in fetal cells from a woman whose first-trimester chorionic villus sampling (CVS) initially showed only 46, XY. Only after exhaustive (500 cells) analysis were four XXY cells found in cultured villi.     

Study on nitrile-degrading microorganisms

Two strains of bacteria were isolated from nitrile polluted soils, and identified as Corynebacterium boffmanii and Arthrobacter flavescens. Acetonitrile, propionitrile, butyronitrile and acrylonitrile were degraded by these bacteria to yield corresponding amides, carboxylic acids and ammonia. The nitrile-degrading abilities of these strains were investigated. The removal rates for the nitrile were nearly 100%, after these bacteria were grown in medium containing 10000 ppm of aceto-, propio-, or butyronitrile at 28 ℃ for 24h. When the reaction mkture consisting of 5000 ppm of above mentioned nitriles or acrylonitrile and 20g (dry cell) /L resting cells of the two strains in 0.06mol/L phosphate buffer (pH7.5) was incubated separately at 25 ℃ with moderate shaking for 15 or 45 min, the nitrile could be degraded completely. The optimum growth conditions for C.hoffmanii and A.flavescens were studied as well.     

Extraction of DNA from amniotic fluid cells for the early prenatal diagnosis of genetic disease

Ten-ml samples of amniotic fluid were taken from pregnancies being terminated at 8–14 weeks' gestation. DNA was extracted from the amniotic cells by sequential centrifugation and analysed using the polymerase chain reaction (PCR). Fifteen samples were analysed for evidence of maternal contamination using Mfd5 oligo-nucleotide primers for repeat polymorphisms. Ten amniotic fluid samples were tested for the Delta-F₅₀₈ deletion characteristic of cystic fibrosis to demonstrate a diagnostic application for the technique. In each case, DNA extracted from fetal tissue from the same pregnancy was included in the controls. In 14 of the 15 cases tested with the Mfd5 primers, both the amniotic fluid DNA and the fetal DNA showed no evidence of contaminating DNA. In one case, neither the amniotic fluid cells nor the fetal cells yielded results. In nine of the ten cases tested with the Delta-F₅₀₈ primers, the amniotic fluid cell DNA provided accurate information about the genetic status of the fetus; in the tenth, the fetal DNA failed to amplify. The results indicate that adequate DNA can be extracted from amniotic fluid from 8 weeks' gestation onward and these samples are suitable for prenatal diagnosis using PCR.