不同系统pJP4质粒介导基因强化降解2,4-D效应研究

以携带pJP4质粒的基因工程菌Pseudomonas putida SM1443∷gfp2x(pJP4∷dsRed)为供体菌,考察了pJP4质粒在4种纯菌中的转移效应;并分别针对活性污泥、生物膜、颗粒污泥和河流沉积物系统,通过实验室小试实验考察了该基因工程菌对不同系统目标污染物2,4-二氯苯氧乙酸（2,4-D）的强化降解效应.结果表明,该基因工程菌中的pJP4质粒能够以广泛的微生物细胞为受体菌发生水平转移;向活性污泥、生物膜、颗粒污泥和河流沉积物系统加入一定量的基因工程菌,对2,4-D的降解都能够产生明显的促进作用.对于活性污泥系统（2,4-D初始浓度为450 mg/L）,强化与对照系统反应143.5　h时2,4-D去除率分别为66％和54％;对于生物膜系统（2,4-D初始浓度为180　mg/L）,强化与对照系统在反应113　h时对其去除率分别为99％和61％;对于颗粒污泥系统（2,4-D初始浓度为160　mg/L）,强化系统2,4-D在62　h接近完全去除,而对照系统66　h去除率仅为26％;对于沉积物系统（2,4-D初始浓度为2　mg/L）,强化与对照系统344　h去除率分别为93％和69％.激光共聚集扫描显微（CLSM）分析揭示并证实了不同基因强化系统接合子的形成与存在.     

Prolonged manganese exposure induces severe deficits in lifespan, development and reproduction possibly by altering oxidative stress response in Caenorhabditis elegans

We examined the possible multiple defects induced by acute and prolonged exposure to high levels of manganese (Mn) solution by monitoring the endpoints of lifespan,development,reproduction,and stress response.Our data suggest that acute exposure (6 h) to Mn did not cause severe defects of life span,development,and reproduction.Similarly,no significant defects could be found for the life span,development,and reproduction in animals exposed to a low concentration of Mn (2.5 μmol/L) for 48 h.In contrast,prolonged exposure (48-h) to high concentrations of Mn (75 and 200 μmol/L) resulted in significant defects of life span,development,and reproduction,as well as the increase of the percentage of population with hsp-16.2::gfp expression indicating the obvious induction of stress responses in exposed animals.Moreover,prolonged exposure (48-h) to high concentrations (75 and 200 μmol/L) of Mn decreased the expression levels of antioxidant genes of sod-1,sod-2,sod-3,and sod-4 compared to control.Therefore,prolonged exposure to high concentrations of Mn will induce the severe defects of life span,development,and reproduction in nematodes possibly by affecting the stress response and expression of antioxidant genes in Caenorhabditis elegans.     

淮北地区矽卡岩型铁铜矿床控矿条件分析与成矿模式

淮北地区位于安徽省北部,是重要金属成矿区之一.地质构造单元归属华北陆块,其矽卡岩型矿床的控矿条件和成矿模式既与华北地区邯邢式接触交代型铁矿床相似而又有区别.邯邢式铁矿主要围岩地层为奥陶系,矿石成分简单,以磁铁矿为主.淮北地区部分矿床具有这一特征,而另一部分矿床的特征与此有较大差异:围岩地层为寒武系,矿石成分复杂,以铁铜矿为主,并含有金、钼等其它有益元素,岩体分叉侵入,多层成矿,矿体产于燕山中期石英二长闪长玢岩与寒武系中上统内接触带及正接触带,镁质矽卡岩较发育,含铜矽卡岩可见于外接触带.为了与邯邢式铁矿区别,称其为前常式铁铜矿.本区矽卡岩型矿床的赋矿层位为中上寒武统-下奥陶统.其中,寒武系铁矿比例43.39%、铜矿比例92.67%、金矿比例100%,奥陶系铁矿比例56.61%、铜矿比例7.33%.本文在介绍地质背景的基础上、较系统地分析了控矿条件和成矿模式,提出了岩浆侵入活动中心(或活动带)与寒武系接触带为重点找矿方向的观点,并明确指出远离侵入中心(带)的岩床,其成矿性差.文中还介绍了覆盖区识别岩浆侵入活动中心(或活动带)的方法.     

浅海目标辐射噪声矢量场特性实验研究

对浅海目标辐射噪声的矢量场特性和矢量噪声测量技术的相对优势开展了实验研究,对实测数据进行了相关的矢量信号的处理与分析。测试结果表明,目标辐射噪声矢量场相关性很强;与传统标量测量方法相比,在浅海低信噪比条件下,矢量法有效提高了目标辐射噪声测量增益。     

全氟辛烷磺化物(PFOS)诱导斑马鱼胚胎p53基因的点突变

将斑马鱼胚胎于0μg·1-1(空白对照),5μg·l-1,16μg·l-1和50μg·l-1全氟辛烷磺化物(PFOS)溶液中暴露染毒5h,采用变性高效液相色谱方法对PCR扩增的含斑马鱼胚胎p53基因外显子7的173 bp的目标片段进行突变分析.结果显示,16μg·l-1和50μg·l-1两个处理组与对照组相比均有显著性差异,表明PFOS可以诱导斑马鱼胚胎p53基因外显子7的点突变.     

Assessment of antibiotic resistance genes in dialysis water treatment processes

• Quantitative global ARGs profile in dialysis water was investigated. • Totally 35 ARGs were found in the dialysis treatment train. • 29 ARGs (highest) were found in carbon filtration effluent. • erm and mtrD-02 occurred in the final effluent. • The effluent was associated with health risks even after RO treatment. Dialysis water is directly related to the safety of hemodialysis patients, thus its quality is generally ensured by a stepwise water purification cascade. To study the effect of water treatment on the presence of antibiotic resistance genes (ARGs) in dialysis water, this study used propidium monoazide (PMA) in conjunction with high throughput quantitative PCR to analyze the diversity and abundance of ARGs found in viable bacteria from water having undergone various water treatment processes. The results indicated the presence of 35 ARGs in the effluents from the different water treatment steps. Twenty-nine ARGs were found in viable bacteria from the effluent following carbon filtration, the highest among all of the treatment processes, and at 6.96 Log (copies/L) the absolute abundance of the cphA gene was the highest. Two resistance genes, erm (36) and mtrD-02, which belong to the resistance categories macrolides-lincosamides-streptogramin B (MLSB) and other/efflux pump, respectively, were detected in the effluent following reverse osmosis treatment. Both of these genes have demonstrated the potential for horizontal gene transfer. These results indicated that the treated effluent from reverse osmosis, the final treatment step in dialysis-water production, was associated with potential health risks.     

重组BALB/C鼠冷诱导RNA结合蛋白CIRP多克隆抗体的制备与鉴定

冷诱导RNA结合蛋白(CIRP)是第一种在哺乳动物细胞中被发现的冷休克蛋白,伴随着细胞冷应激过程过量表达.为进一步研究冷诱导RNA结合蛋白CIRP的生物学功能,构建重组BALB/C鼠CIRP的原核表达载体,重组BALB/C鼠CIRP蛋白经NI-NTA亲和树脂纯化后免疫獭兔制备抗CIRP多克隆抗体,以间接ELISA和Western blot检测抗体效价和抗原特异性.本实验成功构建了CIRP的原核表达载体,在E coli XL-1-blue得到了高效表达,利用原核表达包涵体蛋白免疫獭兔获得了高效价的CIRP多克隆抗体,该抗体能识别肝脏和睾丸中天然的CIRP蛋白.图5参14     

近江牡蛎4种类型GST基因cDNA全序列的克隆与分析

为从分子水平上研究不同类型谷胱甘肽S-转移酶(Glutathione S-transferase,GST)基因在近江牡蛎(Crassostrea ariakensis)等贝类体内代谢去毒过程中的作用,采用RT-PCR及RACE法,分离、克隆得到近江牡蛎肝脏4种类型GST基因cDNA全序列.序列分析结果表明,mu、pi、omega、sigma4种类型GST基因cDNA全长分别为970bp、773bp、999bp、1277bp,分别编码215、207、242、203个氨基酸.构建系统进化树发现,除太平洋牡蛎(Crassostrea gigas)pi型GST外,所有类型GSTs序列都能各自聚集成一簇.     

嗜热脂肪土芽孢杆菌木聚糖酶基因的合成及其在大肠杆菌中的表达

来自嗜热脂肪土芽孢杆菌的木聚糖内切酶XT6在工业上有着重要的应用,已经成功应用于工业规模的生产试验.本文作者在合成XT6基因全序列的同时对其密码子进行了优化,且构建重组质粒在大肠杆菌中高表达.通过优化表达条件,功能正常的XT6基因在大肠杆菌中成功过量表达,蛋白表达量占细胞中总蛋白的65%.重组表达的木聚糖内切酶XT6特性和天然酶相似,以桦木木聚糖为底物测定细胞提取物中木聚糖酶活性,最大活性高达3 030 U/mL.本文首次报道了来自嗜热脂肪土芽孢杆菌中木聚糖酶基因全序列的合成和在大肠杆菌中成功过量表达.图6表1参19     

免耕水稻土固定CO2自养微生物多样性

使用13CO2为标记物,采用稳定性同位素核酸探针(DNA-SIP)技术和微宇宙模拟的方法,对两种南方免耕水稻土中的固定CO2自养微生物群落结构和多样性进行了研究.实验结果表明,经80d的培养后,从13CO2标记处理的土样提取的DNA经氯化铯密度梯度离心后其浮力密度显著区分于12CO2对照组,表明土壤样品中的固定CO2自养微生物对CO2具有同化利用.RT-PCR结果表明两种标记土样DNA密度梯度离心分层的cbbLR基因的拷贝数最高分别为1.36×105拷贝/g干土和2.21×105拷贝/g干土.克隆文库分析和系统发育分析表明两种土壤中的固定CO2自养微生物群落结构具有一定差异.Bradyrhizobium和Rubrivivax是为FG土壤中的主要类群, 占全部克隆数的60.40%和13.86%.而TF土壤的主要类群是Rhodopseudomonas、Rhodospirillum、Methylibium和Variovorax,分别占全部克隆数的20.90%、11.94%、16.42%和10.45%.两种13CO2标记土样的cbbLR基因文库OTU类型、多样性指数均高于12CO2对照文库,其群落结构也有明显的变化.因此,免耕水稻土存在高度多样性的二氧化碳固定自养微生物,在农田土壤碳素循环方面具有重要作用.