转基因玉米的产业现状及发展对策

玉米是重要的粮食作物,近年来转基因玉米逐渐发展,成为转基因作物中的重要一员。通过分析转基因玉米产业现状及重要意义,指出其在科学研究、国家政策和科普教育方面存在的问题,并就转基因玉米产业化发展提出相应对策。     

Screening and Identification of the Cellulase-producing Fungus

In order to isolate the strains which could degrade fiber from the straw,the straw samples were inoculated on the potato agar medium and cultured at room temperature.The isolating strains were inoculated on the cellulose-congo red agar medium,the strains were screened that could produce bigger cellulose-decomposing zone.It was identified by morphological characteristics and molecular biological methods,and characterization of cellulase was analyzed preliminarily.The results showed that the fungus was Aspergillus niger,it could grow at room temperature,and the H/C was 7.64.The highest cellulase activity reached 42.18 U/mL when cultivated at 20 ℃ for 5 days.The optimum pH was 7.0 and the optimum reaction temperature was 20 ℃,the relative cellulase activity still retained above 90% at 20 to 40 ℃ or pH 6.0 to 8.0 for 1 h.The Aspergillus niger was a cold-adapted cellulaseproducing strain,it had strongger producing cellulase ability,and was tremendous potential valuable for microbial development.     

纳米结晶纤维素改善脲醛树脂胶黏剂游离甲醛的研究

为了降低脲醛树脂胶黏剂的游离甲醛释放量,以俄罗斯落叶松浆粕为原料,利用酸水解,硅烷偶联剂改性等制备获得表面改性纳米结晶纤维素(M-NCC),并将M-NCC作为吸附材料用于脲醛树脂基材制备胶合板,研究M-NCC对脲醛树脂胶黏剂游离甲醛的吸附效果和机理。结果表明:透射电镜(TEM)检测可知,制备的NCC颗粒长度约为100~200 nm、直径约为20~30 nm,结晶度为57.3%,相比原始纤维素提高了41.1%;硅烷偶联剂3-(2-氨乙基)-氨丙基甲基二甲氧基硅烷(MCPS)使NCC的浸润性显著增强,当MCPS用量为8%时M-NCC接枝率达到27.2%,M-NCC对脲醛树脂的接触角为65.7°,下降32.7%;由扫描电镜(SEM)照片可观测到,表面改性显著改善了低浓度NCC颗粒在脲醛树脂基材中的分散状态,当M-NCC质量分数2%时,纳米颗粒的分散性能明显下降;M-NCC可有效吸附脲醛树脂基材中的游离甲醛,当M-NCC质量分数1.5%时可致游离甲醛比对照组(0.51 mg/L)下降50.9%。     

马尾松纤维素合成酶基因PmCesA2的克隆及其植物表达载体的构建

为了探究马尾松木材形成的分子机制,以马尾松嫩枝的总RNA反转录得到的cDNA为模板,利用反转录PCR和RACE技术克隆得到马尾松CesA2基因的全长cDNA序列(命名为PmCesA2),序列长度为3 500 bp,包含一个长为3 174 bp的开放阅读框(open reading frame,ORF),编码1 057个氨基酸.序列分析表明:PmCesA2序列与已报道的火炬松CesA2基因(AY789651.1)的相似性达98％.将全长基因克隆到载体pBI121质粒的SnaBI,Sacl双酶切位点之间,构建正义表达栽体pBI121-PmCesA2.     

Immunomodulatory activities of non-prolamin proteins in wheat germ and gluten

Albumin (Alb), globulin (Glo), glutelin (Gll) and glutenin (Gln) were separately extracted from wheat germ and wheat gluten. Amino acisd composition, molecular weight distribution, solubility, in vitro digestibility, and immunomodulatory activities were all analyzed. Gll and Gln have similar molecular weight distributions, which differed from those of Alb and Glo. Alb showed the highest solubility at various pH values (except pH 4.0), whereas Glo showed the highest in vitro digestibility. Glo and Gll have the highest proportion of essential to total amino acids, while Alb and Gll have the highest protein digestibility-corrected amino acid scores. Gll had the strongest immunomodulatory effects in terms of stimulation of RAW 264.7 cells to produce IL-6, TNF-α, and IL-10, and good stimulatory effects on splenocyte proliferation, production of IL-2, phagocytosis, and secretion of nitric oxide in RAW 264.7 cells. Gll can be considered a good protein source for use in health foods.     

转基因马铃薯的研究现状

马铃薯是仅次于水稻、玉米、小麦的世界第四大食用作物。马铃薯主粮化已经成为时下热议的话题之一,其核心优势是产量高、耐瘠薄、消耗水资源少、易于加工等。在耕地和水资源相对紧缺的中国,这些优点无疑具有非常大的吸引力。目前,全球共批准商业化种植的转基因马铃薯40余种,主要性状为:抗病、抗虫和品质改良等,其中部分产品即将在我国申请转基因生物安全证书。详细阐述了转基因马铃薯主要性状的特点、国内外研究进展、审批情况与安全评价的政策,以期为我国政府部门的安全监管及检测标准制定提供参考。     

欧洲木材热处理产业和标准化

欧洲木材热处理产业发达,已建立起较为健全的产业体系.学术界、产业界和政府在技术研发、产品生产、标准化工作和质量认证体系等方面,有效地发挥了各自的作用.芬兰的热处理技术是科技成果产业化的成功典范.建议我国热处理木材产业借鉴欧洲的成功经验,加强产学研合作,促进生产规范化和质量标准化,引入统一的认证机制,促进产业良性发展.     

非线性模型最佳拟合方法的研究

本文对非线性模型具有代表性的拟合方法进行了比较研究，分析各种拟合方法存在的利与弊，研究结果认为三次设计和改进单纯形法都是非线性模型的最佳拟合方法。     

应用辛酸法-DEAE纤维素吸附过滤法提纯的IgG制备RIA用二抗

用辛酸沉淀法结合DEAE纤维素吸附过滤法,从兔、绵羊、驴和人血清中提取IgG,经PAGE和ID分析,其纯度和免疫活性较好.用提纯的兔IgG和人IgG制备的二抗,抗体效价高(驴抗兔IgG高达1024倍,羊抗人IgG达256倍),特异性好,抗体亲和力强,可供作RIA免疫分离沉淀试剂.     

猪对绿肥饲料中蛋白质和纤维素的利用研究

应用＾１５Ｎ标记绿肥饲喂生长猪，开展Ｎ平衡试验，考查绿肥中的蛋白质、氨基酸、纤维素在猪体内的消化、吸收和分布。结果表明，猪对绿肥料中的粗蛋白消化率为５１．３４％，可消化蛋白的利用系数为１５．７６％，氨基酸总量的消化率为６０．４５％，猪对绿肥中纤维素具有一定的消化能力。