雷公藤红素抑制C2C12细胞增殖及诱导其凋亡

雷公藤红素(Celastrol)是传统草药雷公藤根部有效的提取成分,被广泛用于炎症性疾病如类风湿性关节炎、肾炎等治疗.近年来发现,其能抑制肿瘤细胞增殖,具有诱人的肿瘤治疗应用前景.本研究观察到雷公藤红素会抑制C2C12小鼠骨骼肌母细胞的增殖,并可能通过诱导Caspase-3的降解致使C2C12凋亡,提示雷公藤红素临床应用的安全性值得关注.     

高效脱硫异养反硝化菌株的代谢特性研究

以实验室发现的高效脱硫异养反硝化菌种C27为对象,研究其在不同营养环境下的代谢规律.结果表明,自养条件下C27无法生长,异养提供氮源但不加硫源时,菌株仍然具有反硝化能力,乙酸盐降解80%以上,硝酸盐全部被降解,但降解时间变长.分析硫氮比为5∶2、5∶5、5∶8、5∶10条件下,C27对碳氮硫的降解情况,确定最佳的硫氮比为5∶8.     

一株烷烃降解细菌的分离鉴定及其降解特性

从天津海域采集的水样中筛选获得一株烷烃降解细菌,经16S r RNA基因鉴定,结合菌株的形态学特征和生理生化特性分析,鉴定为柠檬酸杆菌属(Citrobacter),命名为Citrobacter sp.TUST-S5.利用GC-MS检测出菌株Citrobacter sp.TUST-S5能降解链长C11—C28的烷烃;对C20以上的长链烷烃,降解率为80%,以上,且降解率随碳链长度的增加呈升高的趋势;菌株的生长曲线及降解曲线显示菌株对烷烃的降解率的变化与菌浓度紧密相关;菌株的乳化活性为47.86%,疏水性为38.30%.菌株Citrobacter sp.TUST-S5对中长链烷烃的降解效果显著,乳化作用明显,对于修复海洋石油污染具有重要的作用.     

电纺煅烧制备TiO_2纳米纤维及其可见光光催化性能

采用静电纺丝-煅烧技术制备了Fe、C、N共掺杂Ti O2纳米纤维,并对其在可见光条件下降解亚甲基蓝模拟染料废水的性能进行了研究.探讨了Fe掺杂量和煅烧温度对Fe/C/N-Ti O2纳米纤维的可见光光催化活性的影响.结果表明,在nFe/nTi为1.5%、煅烧温度为400℃、煅烧时间为1 h的条件下,所制备的Fe/C/N-Ti O2纳米纤维的直径约为(110±50)nm,比表面积达127.48 m2·g-1,Ti O2晶相为锐钛矿相,且Fe、C、N分别以一定的形式掺杂于Ti O2晶格中.同时,在可见光光照2 h下,该纳米纤维对亚甲基蓝的光催化降解率可达98.3%,说明所制备的Fe/C/N-Ti O2纳米纤维具有较高的可见光光催化活性,有望在可见光光降解去除水中有机污染物中获得应用.     

降亚硝酸盐短乳杆菌的诱变选育研究

食品中亚硝酸盐的污染问题一直是食品安全问题的焦点之一,利用生物技术方法降解食品中的亚硝酸盐成为热点.以实验室保存的一株具有降解亚硝酸盐能力的短乳杆菌(Lactobacillus brevis)C2为出发菌株,经过15 W、254 nm、20 cm处紫外诱变(UV)120 s及0.8%的硫酸二乙酯(DES)于37℃诱变40 min的复合诱变,进行筛选,获得高效降解亚硝酸盐菌株UV6-DS2,相对于出发菌株,在400 mg/L亚硝酸盐的环境下,经12 h降解后,亚硝酸盐的降解率由92.8%提高到97.8%,探究其于食品中的应用可以有效地降低食品中亚硝酸盐的含量.     

基于JMP软件的Lasso及岭回归在水稻全基因组预测中的应用

全基因组选择是21世纪动植物育种的一种重要的选择策略,其核心就是全基因组预测,即基于分布在整个基因组上的多样性分子标记来对育种值进行预测,为个体的选择提供依据.但目前提出的大多数全基因组预测方法都涉及到相当复杂的算法并要求使用者具备熟练的编程能力,因此很少在实际育种中得到有效的应用.对统计软件JMP在水稻全基因组预测中的应用做了探索研究,利用其中的两种正则化回归方法(Lasso和岭回归)预测产量及其相关性状的育种值,结果表明两种方法对这些性状均有较好的预测效果,但Lasso优于岭回归,预测效果因性状不同也有差异,4个性状预测效果的次序为:千粒重分蘖数单株谷粒数产量.鉴于JMP软件的强大的分析能力、友好的用户界面和可操作性,本研究的结果可以为育种工作者在选择应用全基因组预测的分析工具方面提供较好的参考.     

C/Bi2 MoO6复合材料的合成及其可见光光催化性能研究

采取溶剂热法制备C/Bi_2MoO_6光催化复合材料,通过SEM、XRD和XPS等手段研究催化剂的形貌,晶相结构和元素组成等,并在可见光下进行RhB (罗丹明B, C_(28)H_(31)ClN_2O_3)以及BPA (双酚A,(CH_3)_2C(C_6H_4OH)_2)的降解试验.当C负载量为5%时,C/Bi_2MoO_6复合材料的光催化降解RhB具有最高的光催化活性,60 min内降解率达到93%,速率常数是纯Bi_2MoO_6的4.6倍.电阻抗和光致发光光谱结果表明,非金属C掺杂后的光催化剂促进了光生载流子的分离,有助于提高光催化性能.该催化剂经过5次循环实验之后,光催化活性损失较小,说明具有较高的稳定性.通过添加牺牲剂捕获不同的活性物质,证明了h~+为主要活性物种,并探索性地提出了相应的光催化机理.     

营养物添加对生活垃圾降解及渗滤液水质影响

为研究微生物营养物质添加对生活垃圾降解及渗滤液水质的影响,在厌氧填埋的生活垃圾中分别加入维生素C、氯化钾、磷酸二氢钾、氯化铵及氯化钾、磷酸二氢钾、氯化铵的混合物,考察各垃圾层的沉降高度和渗滤液COD、氨氮的质量浓度.实验结果表明:维生素C、氯化钾、磷酸二氢钾、氯化铵及氯化钾、磷酸二氢钾、氯化铵的混合物均能够加速生活垃圾降解,其中维生素C加速垃圾降解的效果最好.同时,生活垃圾降解速率越快,产生渗滤液的COD和氨氮质量浓度越高.     

鞘氨醇单胞菌对微囊藻毒素-RR的降解作用与影响因素分析

为探索微囊藻毒素微生物降解机制,研究了鞘氨醇单胞菌对微囊藻毒素-RR(MC-RR)的降解作用与影响因素.通过色谱及质谱方法阐明了鞘氨醇单胞菌对MC-RR的降解能力及途径,结合实时荧光定量聚合酶链式反应技术和酶活性分析探究了反应温度、营养基质及同类毒素(微囊藻毒素-LR,MC-LR)的影响及机制.结果 表明:鞘氨醇单胞菌对MC-RR的最高降解速率达0.29 mg/(L·h),降解产物分别为C49 H77 N13 O13 C32 H47 N4 O8、C12H19N3O6和C20 H29 NO3;温度影响酶MlrA活性,在20～40℃范围内最适温度为30℃;提高磷质量浓度(100 mg/L K2 HPO4)可刺激mlrA基因表达,使降解速率增加27.59％;提高碳质量浓度(100 mg/L葡萄糖)将抑制mlrA表达,使降解速率下降86.71％;MC-LR和MC-RR竞争性结合MlrA,使MC-RR降解速率下降4.44％.鞘氨醇单胞菌对MC-RR的降解能力较强,并受到温度、营养基质及MC-LR浓度的影响.     

菲降解菌株的筛选及特性研究

目的 以菲为模型,分离能够以菲作为惟一碳源和能源进行生长繁殖的微生物,研究菲的降解特性,为多环芳烃的生物降解机制和工业应用的研究奠定基础.方法 从焦化污水池附近的土壤中,通过选择性富集培养,筛选、分离具有菲降解能力的茵株,通过16s rDNA序列分析鉴定其种属,并在不同的温度和pH条件下,测定菌株的生长及对菲的降解性能.结果 得到两株较好的菲降解茵,初步鉴定其分别属于不动杆菌属和假单胞茵属.其最适生长温度均为37℃,最适降解温度分别为34℃和37℃,最适生长pH分别为7.0和6.5～7.0,最适降解pH为7.0和6.5,两天内菲的最大降解率分别达到80.4%和86.6%.结论 分离得到的两株茵对菲都具有较好的降解能力,且假单胞茵略微优于不动杆菌,降解机制及降解策略、工程应用研究正在进行中.     

Cupriavidus metallidurans CH34中2个苯酚降解基因簇的筛选与功能鉴定

Cupriavidus metallidurans(C.metallidurans)CH34是一种重金属耐受性细菌,能在以苯酚、甲苯酚、苯甲酸、苯胺等芳香族化合物为唯一碳源和能源的培养基中生长,其基因组中含有2个苯酚降解基因簇.以载体pIndigo-BAC 5构建C.metallidurans CH34的细菌人工染色体(bacterial artificial chromosome,BAC)文库,获得约3万个克隆,平均插入片段大小为30 kb,插入频率为98%,推测该文库覆盖CH34基因组约1 240倍.用PCR筛选文库中的3 000个单克隆,共获得9个阳性克隆,其中5个克隆含有长基因簇,4个含有短基因簇,并从中得到含有全长苯酚降解基因簇的克隆.利用以苯酚为唯一碳源的无机盐培养基,研究2个基因簇在大肠杆菌中的表达情况.结果显示,两个基因簇均表现出了苯酚降解能力,短簇的降酚能力要优于长簇.     

抗稻瘟病水稻BAC文库的构建与鉴定

水稻是一种重要的粮食作物，同时也是一种重要的单子叶植物模式.稻瘟病是水稻生长中的一种严重病害，因此分离和克隆新的稻瘟病抗病基因具有重要的应用价值.以一个抗稻瘟病农家种水稻为材料，以plndigoBAC5为载体，构建了细菌人工染色体（BAC）文库.该文库共有90 000个转化子，插入频率99％，插入片段平均长度为105 kb，由此推测这个文库覆盖水稻基因组约20倍.利用其中的45 000个转化子建立了4维PCR筛选体系，并且通过4维PCR筛选体系，筛选获得了7个含水稻分蘖基因（MOC1）的阳性克隆.因此该文库是一个高质量、高覆盖率的水稻BAC文库，能有效用于目的基因的分离.     

盐藻（Dunaliella viridis）细菌人工染色体文库的构建和鉴定

盐藻具有极强的耐盐能力，是研究植物耐盐机制的模式系统.为了对其耐盐机制进行深入的 研究，以pCC1BAC为载体，构建了盐藻的细菌人工染色体（BAC）文库.该文库共有9 216 个转化子，插入片段平均长度为55 kb，以单克隆形式保藏在96块96孔板中，并建立了四维P CR基因筛选体系，可以通过4轮PCR快速筛选获得阳性单克隆.根据本实验室分离到的两个盐 藻基因的cDNA序列（ DvSPT2和DvTPSP ）设计引物，通过PCR从该文库中各筛到4个阳性BA C克 隆，说明该文库能有效用于分离盐藻基因的基因组序列，据此推测该文库约覆盖4倍盐藻基 因组序列.     

Construction and characterization of a bacterial artificial chromosome library of rice 5460F

Thermo-sensitive genie male sterile (TGMS) rice has a number of desirable characteristics for hybrid rice production. Many studies have demonstrated that the sterility of TGMS rice is controlled by a single recessive gene. It has been mapped for the first time on chromosome 8 and namedtms 1. Several AFLP markers which tightly linked to thetms 1 gene have been identified recently. In order to develop a detailed physical map of thetms1 gene-encompassing region and finally clone thetms1 gene, a bacterial artificial chromosome (BAC) library of rice 5460F (the fertile mutant line of TGMS rice 5460S) using a modified vector pECBAC1 has been constructed. The constructed 5460F BAC library consists of 16 896 clones with an average insert size of 119 kb, which represents about 4.7 times rice haploid genome equivalents. Neither chloroplast nor mitochondrial DNA was detected from the library. The library was screened with three single copy sequence amplified fragment length polymorphism (AFLP) markers which tightly linked totms1 gene as probes and eight positive clones were identified.     

A gene expression atlas of the central nervous system based on bacterial artificial chromosomes

The mammalian central nervous system (CNS) contains a remarkable array of neural cells, each with a complex pattern of connections that together generate perceptions and higher brain functions. Here we describe a large-scale screen to create an atlas of CNS gene expression at the cellular level, and to provide a library of verified bacterial artificial chromosome (BAC) vectors and transgenic mouse lines that offer experimental access to CNS regions, cell classes and pathways. We illustrate the use of this atlas to derive novel insights into gene function in neural cells, and into principal steps of CNS development. The atlas, library of BAC vectors and BAC transgenic mice generated in this screen provide a rich resource that allows a broad array of investigations not previously available to the neuroscience community.     

Screening and Insert Size Analysis of Candidate C-Genome BAC Clones from Brassica napus

Thirty-two C-genome specific candidate bacterial artificial chromosome (BAC) clones were successfully screened from the BAC library by four-dimensional PCR method with the primer pairs of 75 simple sequence repeat (SSR) markers located in the nine C-genome linkage groups of Brassica napus. The screened 32 BAC clones have an average insert size of 114.2 kb with a range of 30-190 kb. They are the first set of C-genome BAC clones screened from B. napus genomic BAC library. The average insert size of this set of BAC clones presented that the constructed BAC library had a high quality. This set of BAC clones can be used as markers to identify individual chromosomes of B. napus C-genome.     

Physical location of the ricePi-5(t), Glh andRTSV genes by ISH of BAC clones

Mapping of low or single-copy sequences on plant chromosomes has proven difficult because of very low frequency of signal detection. Rice BAC library is being used widely in rice genome research due to its distinctive advantages over other library systems. In this study, two biotin-labeled rice BAC clones closely linked to a rice blast resistance, green leafhopper resistance and tungro spherical virus resistance gene,Pi-5(t), Glh, RTSV, werein situ hybridized to rice chromosomes. They were located on the long arm and short arm of chromosome 4 with FL value of 40% and 100% respectively. The frequency of signal detection reached 46.8% and 59.2%. The signal location were consistent with the selective marker on rice saturated molecular map. The results demonstrated the advantages to locate BAC clones to chromosomes byin situ hybridization and will facilitate the rice low or single-copy gene location by using the BAC library. Supported by the National Natural Science Foundation of China and the Doctorate Vesting Point Foundation of the Education Department of the People's Republic of China Yan Huimin: born in 1964, Lecturer     

Construction of a BAC library from cucumber （Cucumis sativus L.） and identification of linkage group specific clones

A bacterial artificial chromosome （BAC） library consisting of 19,200 clones with an average insert size of 105 kb has been constructed from a cucumber （Cucumis sativus L.） inbred line S94, derived from a cultivar in North China. The entire library was equivalent to approximately 5 haploid cucumber genomes. To facilitate chromosome engineering and anchor the cucumber genetic linkage map to its chromosomes, 15 sequence-characterized amplified regions （SCAR） and seven simple sequence repeats （SSR） markers from each linkage group of cucumber were used to screen an ordered array of pooled BAC DNA with polymerase chain reaction （PCR）. Fifteen markers gave at least two positive clones. As a result, 22 BAC clones representing 7 linkage groups of cucumber were identified, which further validated the genome coverage and utility of the library. This BAC library and linkage group specific clones provide essential resources for future research of the cucumber genome.     

Construction of a BAC library from cucumber (Cucumis sativus L.) and identification of linkage group specific clones

A bacterial artificial chromosome (BAC) library consisting of 19,200 clones with an average insert size of 105 kb has been constructed from a cucumber (Cucumis sativus L.) inbred line S94; derived from a cultivar in North China. The entire library was equivalent to approximately 5 haploid cucumber genomes. To facilitate chromosome engineering and anchor the cucumber genetic linkage map to its chromosomes, 15 sequence-characterized amplified regions (SCAR) and seven simple sequence repeats (SSR) markers from each linkage group of cucumber were used to screen an ordered array of pooled BAC DNA with polymerase chain reaction (PCR). Fifteen markers gave at least two positive clones. As a result, 32 BAC clones representing 7 linkage groups of cucumber were identified, which further validated the genome coverage and utility of the library. This BAC library and linkage group specific clones provide essential resources for future research of the cucumber genome.     

Construction of a BAC library from cucumber (Cucumis sativus L.) and identification of linkage group specific clones

A bacterial artificial chromosome (BAC) library consisting of 19,200 clones with an average insert size of 105 kb has been constructed from a cucumber (Cucumis sativus L.) inbred line S94; derived from a cultivar in North China. The entire library was equivalent to approximately 5 haploid cucumber genomes. To facilitate chromosome engineering and anchor the cucumber genetic linkage map to its chromosomes, 15 sequence-characterized amplified regions (SCAR) and seven simple sequence repeats (SSR) markers from each linkage group of cucumber were used to screen an ordered array of pooled BAC DNA with polymerase chain reaction (PCR). Fifteen markers gave at least two positive clones. As a result, 32 BAC clones representing 7 linkage groups of cucumber were identified, which further validated the genome coverage and utility of the library. This BAC library and linkage group specific clones provide essential resources for future research of the cucumber genome.