Nitrogen removal and metabolic profiling of a cold-adaptive and biofilm producing paddy soil bacterium Cupriavidus sp. PDN31

To assess the physiology and low temperature adaptability of the key players of nitrification and denitrification, denitrifying bacteria were isolated and characterized from the selected paddy fields. Bacterial strains belonging to Cupriavidus and Ochrobactrum sp. were explored through the selective screening of heterotrophic nitrifying and aerobic denitrifying bacteria. The direct implication of nitrate removal in the natural sample was estimated by taking the nitrate supplemented soil as well as the enriched culture. A more prominent cold-adaptive bacterium was identified as Cupriavidus sp. PDN31. The utilization of ammonium, nitrate, and nitrite and the presence of nitrous oxide reductase (nosZ) gene, catalyses the first step of the denitrification conferred its heterotrophic nitrification and aerobic denitrification ability. The ammonium, nitrate, and nitrite removal efficiency of PDN31 was found to be 92.1%, 93.5%, and 99.8%, respectively. The functional traits, evaluated from metabolizing various nitrogen substrates (Biolog) suggested its ability to utilize some sources as L-arginine, L-asparagine, L-cysteine, L-glutamic Acid, L-glutamine, L-histidine, L-citrulline and N-acetyl-L glutamic acid. The adaptive behaviour of PDN31 with its ability to remove nitrogen and induced biofilm production under low temperature regime makes it a suitable candidate among the plethora of microorganism resided in any agriculture environment.     

灰树花菌丝体胞内多糖对于小鼠的免疫调节作用

为研究灰树花发酵产物提取出的胞内多糖的免疫活性,采用50只雄性昆明小鼠,随机分为5组,每组10只,设100、200和400mg/(kg·d)3个水平处理组,并设阳性对照组(黄芪多糖400mg/(kg·d))和阴性对照组(生理盐水),饲养30d后观察多糖对细胞免疫功能的影响。通过流式细胞仪检测脾细胞表面分子的CD4和CD8及对T淋巴细胞增殖的影响;用实时荧光定量PCR(RT-PCR)检测其细胞因子IL-6、IL-8、CRP和TNF-α的表达。结果表明:灰树花胞内多糖使小鼠脏器显著增大(P≤0.05);并显著增加了脾淋巴细胞的增殖能力(P≤0.05);对于T淋巴细胞亚群中免疫细胞CD4/CD8的比值随着用药量的增加而提升(P≤0.05);同时小鼠肠道中的细胞因子IL-6、IL-8和TNF-α的分子表达量起到了上调作用(P≤0.05);并且下调了炎症因子CRP的分子表达量(P≤0.05)。灰树花菌丝体胞内多糖能使小鼠体内免疫器官增大,免疫细胞分泌增多,相关免疫因子表达量增加。     

青海省海北州藏羊群中牛病毒性腹泻病毒和羊边界病毒的流行病学调查

为掌握青海省海北州藏羊群中牛病毒性腹泻病毒和羊边界病毒的感染情况,本研究采用RT-PCR方法分别对青海省海北州的161份健康藏羊血清样品和34份腹泻藏羊组织样品进行了BVDV和BDV的抗原核酸检测。结果显示：195份样品中BVDV和BDV总阳性率分别为29.74 %和14.36 %;161份健康藏羊血清样品中BVDV和BDV平均阳性率分别为26.71 %和11.80 %,BVDV/BDV混合感染率为4.35 %;34份腹泻藏羊组织样品中BVDV和BDV平均阳性率分别为44.12 %和26.47 %,BVDV/BDV混合感染率为17.65 %。本研究表明青海省海北州健康藏羊群和腹泻藏羊群中均存在BVDV、BDV的单独感染以及混合感染,且感染情况在个别养殖场(户)较为严重,本研究为青海藏羊的综合防控措施提供了指导依据,丰富了我国羊群中BVDV和BDV的流行病学资料。     

进境荷兰百合中车前草花叶病毒的分子鉴定及序列分析

对一株进境隔离种植中疑似病毒症状的荷兰百合进行检测、鉴定。采用RT-PCR方法对疑似样品的部分基因序列进行扩增、测序,比对后,建立系统发育树进行亲缘关系分析。结果表明,采用香石竹潜隐病毒属和马铃薯X病毒属(CarlapCar1I/M4T和Potex 5/Potex 1RC)简并引物均可扩增到预期大小的片段(1 257 nts和737 nts)。序列分析显示,扩增片段与车前草花叶病毒(Plantago asiatica mosaic virus,Pl AMV)3'端序列(包含TGBp2、TGBp1、CP,3’-NTS)和部分依赖于RNA的RNA聚合酶基因序列一致性可达79.9%~99.5%和80.5%~99.3%。利用PlAMV的特异性引物(PlAMV-cpup/PlAMV-cpdw)进行检测,结果进一步证实该百合样品含有PlAMV。通过建立系统发育树得出,该病毒分离物与来自荷兰的PlAMV百合分离物优先聚为一簇,表明二者的亲缘关系最近。这是我国口岸首次截获车前草花叶病毒的报道。     

Development and Application of Duplex Real-time RT-PCR Assay for Detection of H1 and H3 Subtype Swine Influenza Viruses

To establish a rapid, accurate method to diagnose and detect H1 and H3 subtype swine influenza viruses (SIV) at the same time, the specific primers and TaqMan probes were designed according to the conserved region of the HA gene of H1 and H3 subtype SIV. A duplex Real-time RT-PCR assay was developed for detection of H1 and H3 subtype SIV. The results showed that the Real-time RT-PCR could detect 10² copies/μL of H1 and H3 subtype SIV, the sensibility was well. Coefficient of variation of Ct value between repeating groups were all below 5%, the repeatability was favorable. The results were negative for the detection of H4, H5, H7, H9 subtypes SIV, classical swine fever virus, porcine reproductive and respiratory syndrome virus, foot and disease virus and pseudorabies virus, the specificity was fine. One sample was H1 subtype SIV, and one sample was H3 subtype SIV, by the established assay, the positive rate was 1.16%. The method was highly accurate, rapid, sensitive and specific, and could provide a method for rapid detection and epidemiological investigation of H1 and H3 subtype SIV.     

藏羊白细胞介素-7基因的PCR扩增及生物信息学分析

为了获得藏羊白细胞介素-7（interleukin-7,IL-7）基因序列,并研究其序列特征及编码蛋白的结构和功能,本试验采用RT-PCR方法,从藏羊脾脏中扩增了IL-7基因,应用DNAStar软件分析该基因的核苷酸和氨基酸序列,与经BLAST比对后的参考序列进行同源性比对,并构建系统进化树,同时利用DNAStar软件和在线服务器预测该基因编码蛋白的二级结构、三级结构、亲水性、信号肽和蛋白翻译后修饰位点。结果表明,藏羊IL-7基因长度为531 bp（含终止密码子）,编码176个氨基酸。藏羊IL-7基因与绵羊、山羊、藏羚羊、水牛、瘤牛、美洲草原野牛、黄牛和牦牛的IL-7基因核苷酸序列同源性在97.2%~99.8%之间,氨基酸序列同源性在94.9%~99.4%之间,藏羊与绵羊的亲缘关系最近。蛋白结构预测结果表明,IL-7蛋白主要由α螺旋组成,是一种亲水性和分泌型蛋白。该蛋白含有6种蛋白质翻译后修饰位点,包括1个N-豆蔻酰化位点、1个酰胺化位点、1个cAMP和cGMP依赖性蛋白激酶磷酸化位点、3个N-糖基化位点、4个蛋白激酶C磷酸化位点、6个酪蛋白激酶Ⅱ磷酸化位点。本研究结果可为藏羊IL-7基因的进一步研究与临床应用提供参考。     

不同地区稻农超级稻和常规稻生产经济效益比较——基于浙江、湖南2省413户的调查

利用2009年浙江、湖南2省9县(市、区)12个乡镇38个行政村413户农户的调查数据,对浙江省与湖南省稻农生产的超级稻品与常规稻的经济效益进行了比较分析.结果显示:超级稻的单位面积产量、生产成本、总产值、净产值、纯利润均高于常规稻,但成本利润率低于常规稻0.91个百分点;超级稻品种单产湖南高于浙江,常规稻品种单产湖南低于浙江;超级稻生产成本利润率浙江为29.366%,湖南为12.843%,常规稻生产成本利润率浙江为27.348%,湖南为15.567%;在调查的品种中,成本利润率在40%以上的超级稻品种有新两优6号和中浙优1号,常规稻品种有秀水114.超级稻生产在产量和推广面积上还有较大的潜力,在大力推广超级稻品种的同时,各级政府主管部门也不能忽视优质常规水稻的推广.     

巴西橡胶树胚胎晚期丰富蛋白基因的克隆及序列分析

根据抑制性消减杂交文库分离的EST片段,采用3’-RACE技术从巴西橡胶树胶乳中获得HbLEA14基因的全长cDNA序列,其ORF长456 bp,编码151个氨基酸,预测HbLEA14蛋白分子量为16.58 ku,等电点为5.10。同源性比对显示,HbLEA14与蓖麻RcLEA14、乳浆大戟EeLEA14、陆地棉GhLEA14、大豆GmLEA14、拟南芥AtLEA14、番茄SlER5的同源性分别为88%、80%、75%、73%、65%和61%,属于非典型第2组LEA蛋白。RT-PCR结果显示,死皮植株胶乳中HbLEA14的表达量明显高于健康树。     

The relationship between cellular immune response to foot-and-mouth disease virus Asia 1 and viral persistence in Indian cattle (Bosindicus)

Foot-and-mouth disease (FMD), the most contagious animal disease, is associated with persistent viral infection in ruminants, despite the induction of systemic immune response. The present study was performed to decipher the relation between the persistent FMD virus (FMDV) infection and cellular immune response in Indian cattle (Bosindicus) following experimental inoculation of FMDV Asia 1. Persistent viral infection (carriers) was detected by antigen capture RT-PCR on the oesophageal-pharyngeal fluid. Viral excretion was found to be intermittent and strongly variable among the persistently infected Indian cattle. Lymphocyte proliferative (LP) response, assessed as reactivity of peripheral blood mononuclear cells to FMDV Asia 1 antigen (Ag) was of low magnitude indicating a weak primary cellular immune response following infection. LP response to FMDV Ag was higher among the non-carriers than carriers of FMDV Asia 1. An enhanced LP response was associated with the lack of virus shedding in the OPF. The findings of this study are suggestive of relationship between cellular immune response and virus excretion during persistence of FMDV Asia 1 in infected cattle.