棉花黄萎菌拮抗菌BDT-25的鉴定及抗菌蛋白产生条件研究

拮抗细菌BDT_25是从根际土壤中分离到的一株对棉花黄萎病菌具有强烈抑制作用的芽孢杆菌。经生理生化特征的鉴定,证明BDT_25菌株为枯草芽孢杆菌(Bacillus subtilis)。此外,该菌株还对棉花枯萎病菌、棉花立枯病菌等10种其他病原真菌的生长具有显著的抑制作用,为一株广谱拮抗细菌菌株。通过对BDT_25菌株培养条件的研究发现,采用NB液体培养基,28℃,170 r/min培养48 h所得发酵液对棉花黄萎病菌的抑制作用最强。其发酵液经硫酸铵沉淀粗提到对棉花黄萎病菌具有抑制作用的提取物,进一步实验表明,该拮抗物质对热和多种蛋白酶敏感,证实其为抗菌蛋白。     

转基因植物食用安全评价

2014年全球转基因植物种植面积达到1.815亿hm2,转基因植物商业化发展给全球农业和环境带来巨大收益,但是其安全性问题仍然受到广泛争议。目前,对转基因植物的安全评价在全球范围内已经建立起较为完善的体系,但是各国政府对评价程序的具体要求还存在差异。为了在法律法规层面规范转基因植物安全评价程序,中国农业部颁布了《转基因植物安全评价指南》,涵盖了详细的转基因植物及其产品的安全性评价内容。本文结合案例分析,对该指南中的食用安全评价部分详细解析和论述了包括营养学、毒理学、致敏性以及非期望效应等安全评价程序,旨在为我国转基因植物的食用安全评价提供有益的指导与借鉴。     

Long-term monitoring of feral genetically modified herbicide-tolerant Brassica napus populations around unloading Japanese ports

Genetically modified, herbicide-tolerant (GMHT) Brassica napus plants originating from seed spill have recently been found along roadsides leading from Japanese ports that unload oilseed rape. Such introductions have potential biodiversity effects (as defined by the Cartagena Protocol): these include replacement of native elements in the biota through competitive suppression or hybridization. We conducted surveys in the period 2006–2011 to assess such threats. We examined shifts in the population distribution and occurrence of GMHT plants in 1,029 volunteer introduced assemblages of B. napus, 1,169 of B. juncea, and 184 of B. rapa around 12 ports. GMHT B. napus was found around 10 of 12 ports, but its proportion in the populations varied greatly by year and location. Over the survey period, the distributions of a pure non-GMHT population around Tobata and a pure GMHT population around Hakata increased significantly. However, there was no common trend of population expansion or contraction around the 12 ports. Furthermore, we found no herbicide tolerant B. juncea and B. rapa plants derived from crosses with GMHT B. napus. Therefore, GMHT B. napus is not invading native vegetation surrounding its populations and not likely to cross with congeners in Japanese environment.     

Influence of soil properties on the vertical movement of genetically-marked Pseudomonas fluorescens through large soil microcosms

Summary Vertical translocation of the introduced transposon Tn5-tagged Pseudomonas fluorescens cells was studies after irrigation of 50-cm long soil columns of loamy sand. The soil in the columns was slowly brought to saturation using groundwater, and enough water was then slowly added to permit collection of the percolated water. Introduced bacteria were transported to lower soil layers to a significantly higher degree in undisturbed soil cores than in repacked cores; water transport was hampered in both core types due to high soil bulk densities. Soil bulk density affected the degree of transport of the introduced cells; progressively more cells were translocated to deeper soil layers and into the percolation water at decreasing soil bulk densities. Repeated percolation of soil at a bulk density of 1.25 caused an increase in Tn5-tagged cell numbers in the lower soil layers and in the percolated water. Further, cells initially introduced into a dry (5.3% moisture) soil were translocated to a lesser extent than cells introduced into a wetter (13% moisture) soil. Finally, wheat roots enhanced the water-induced transport of introduced cells to the 40- and 50-cm deep soil layers and into the effluent, but not to the remaining soil layers. Large soil columns such as those used in the present study are useful in assessing the transport and survival of introduced bacterial cells in soils under a variety of simulated environmental conditions.     

高温木质素降解菌Geobacillus caldoxylosilyticus J16的筛选及其产酶发酵性质研究

从张家界、白云山采集到的朽木及落叶中,经分离、纯化后,获得了一株高温木质素降解菌,命名为地芽孢杆菌（Geobacillus caldoxylosilyticus J16）,此菌嗜热,耐高温,只降解木质素且不降解纤维素,对造纸业和可再生能源产业具有重要意义。本文通过对木质素中两种酶木质素过氧化物酶、锰过氧化物酶活性的研究,确定了木质素过氧化物酶的最适温度为65℃,最适PH为4,在55℃至70℃之间时酶活力较其他温度高且较稳定;锰过氧化物酶最是温度为60℃,最适pH为3在温度为55℃至65℃之间时,活力较其他温度高。作者发酵了黄豆杆、玉米杆、芝麻杆、油菜杆、锯末、小麦杆这六种农业废弃物,通过发酵前后的比较,说明了J16菌株对木质素降解的最大减少量为7.5%。上述数据显示此菌可以应用于废弃秸秆的处理和造纸厂污水的处理,对环保有重要意义.     

加快发展现代农业|大力推进转基因生物育种产业化

生物技术同常规农业技术结合，推进转基因生物育种研究开发和产业化，将对我国现代农业的发展发挥巨大作用。综述了国内外转基因农作物研究和产业化的最新进展，并建议：①实行积极的产业化政策；②加强科普宣传，理性认识转基因安全；③加强基础研究，提高自主创新能力。     

几株优势菌降酚生态条件的研究

对3株耐酚能力达1760mg/L的优势菌W1,W2和M2的适宜生态条件进行了研究。结果表明,在温度为15～50℃时,随着温度提高,各所选菌株降酚活性增强。在pH值为4.5～9.5时,W2活力较高,pH值为7.5时24h内降酚达100%。富营养条件比贫营养条件更能提高菌株的降酚以及降硫、降氮、降COD等其他污染物的效率。当苯酚质量浓度较小时,各菌株在6h内降酚效率均可达100%;苯酚浓度较大时,W1具有较强的降酚能力。在菌株接种密度为1∶10的情况下,各菌株经济实用且降酚效果好。     

拮抗菌对香蕉枯萎病菌的抑菌作用初步研究

从土壤中分离到一株对香蕉枯萎病菌(Fusarium oxysporum f.sp.cubense)具有抑制作用的拮抗细菌--假单胞杆菌(Pseudomonas sp.),并对其抑菌效果、热稳定性以及作用机理进行了初步研究.结果表明,拮抗细菌发酵液及其无菌滤液对香蕉枯萎病菌的生长及其分生孢子的萌发具有显著的抑制作用(P＜0.05),并导致病菌菌丝和分生孢子芽管扭曲、膨大;拮抗细菌发酵液经121℃处理30min后,对病菌生长的抑制作用降低.     

白斑综合征病毒与凡纳滨对虾肠道菌群区系之间关系的初步研究

比较了同一养殖池中的感染白斑综合征病毒(WSSV)和未感染WSSV的凡纳滨对虾的肠道菌群,旨在探讨对虾肠道菌群与机体健康状态之间的关系。感染WSSV对虾肠道的细菌总数为1.06×106CFU/尾,显著高于未感染WSSV的对虾(1.78×105CFU/尾;P<0.05),且其肠道中的细菌分别属于弧菌属、气单胞菌属、海水球菌属、盐水球菌属和乳酸杆菌属;染WSSV的对虾(P<0.05),气单胞菌的比例显著的低于感染WSSV的对虾(P<0.05);盐球菌所占的比例两者之间差异不显著。结果显示,两种对虾在肠道菌群组成和细菌组成和细菌数量上存在显著的差异,初步表明对虾肠道菌群区系和机体的健康状态密切相关。     

德威乐植物营养剂的生产工艺及施用效果

德威乐植物营养剂是一种新型、高效、环保、无公害的叶面肥,介绍了该产品的生产工艺及主要营养组成。通过多点、多品种的田间试验,探讨了德威乐植物营养剂对农作物产量和品质的影响。结果表明,德威乐有利于农作物的营养吸收,能使作物生长所需的营养均衡,实现速效性和长效性的平衡,具有现代农业中新型高效生物肥料的特点,对茶叶、蔬菜、沙田柚、水稻等均有不同的增产效果,并能显著改善农作物的品质。