诱变

Because of the great differences of inducing conditions between space and on the earth, space mutation has exhibited the wide application prospect in breeding, but the studies on quality traits by space mutation are singular.

突变体MLA-1与原亲本的SSR多态性比较研究的结果表明，MLA-1和原亲本"美香占"在DNA水平上表现出明显的不同，选用180对微卫星引物对MLA-1和原亲本进行SSR分析，有22.8%的扩增产物在两个材料间表现出了多态性，说明空间诱变后发生多位点的突变。

In high selectivity enrichment culturing process and rapid screening procedure, the succinic acid producers with starchness and saccharide were isolated from bovine rumen.

本研究通过采用选择性较强的富集培养和快速准确筛选程序，从牛瘤胃中分离出适于淀粉质原料的琥珀酸产生菌，并进行相关的生理生化鉴定：通过紫外照射诱变育种得到琥珀酸高产突变株，优化培养基组成并确定最适发酵培养条件。

In order to find new kinds of antibacterial agents, a primary screening model has been set with the DNA gyrase B subunit as a target, and then the active compounds of positive strain were purified. From Mycobacterium phlei, we isolated a novobiocin supersensitive mutant M.phlei SS12 and a resistant ~mutant M.phlei RR11 with NTG and UV.

实验采用Mycobacteriumphlei为出发菌株，利用NTG和紫外线复合诱变得到新生霉素特异性的超敏菌株M.phleiSS12和耐药菌株M.phleiRR11，建立了以DNA回旋酶B亚基为靶点的抗结核药物的筛选模型；并应用此模型对1600株真菌和100株放线菌发酵液进行了初筛，获得了38株阳性菌，阳性率为2.4%；对阳性菌株3277的发酵液进行了提取分离，得到X1和X2两个活性化合物。

Methods The expression plasmid pSVvWF containing full-length cDNA of vWF was used to site direct mutagenesis by polymerase chain reaction and transitorily expressed in the COS-7 cells, vWF:Ag in the supernatant and the cell lysate between wild type and pSVAla737Glu vWF were measured.

用聚合酶链反应的方法对野生型的vWF全长表达质粒进行体外定点诱变，在COS-7细胞中进行表达。

N L-Leucine Producer,Strain No .145,was obtained from mutants resistant to α-amino-β-hydroxyl valeric acid and rifampin by mutagenizing Brevibacterium Tianjinese T6-13 with ul-traviolet rays,It produced L-Leucine up to 32mg/mL on shaker and 21.8mg/mL of L-Leucine was produced in 16 liter fermentor in 60 hours.

以天津短杆菌T6～13为出发菌株，采用紫外线进行诱变处理，筛选α－氨基－β－羟基戊酸和利福平抗性突变株，获得一株L－亮氨酸产生菌No.145，L－亮氨酸摇瓶产量可以达32.1mg／mL。在16L发酵罐中培养60h，L－亮氨酸产量可以达21.8mg／mL葡萄糖转化率可以达20％。

In order to prevent linear PCV2 cyclization, PCR mutagenesis was used to construct the first molecular clone (pSK-2PCV2) by ligating two copies of the complete PCV2 genome with the pBluescript SK vector. In addition, pSK-PCV2 and ds-PCV2 were constructed. PK-15 cells were transfected with above three infectious clones.

本研究应用PCR诱变技术解决了外源片段易于自连的难题，成功将2个PCV2 SD1株全基因组(DQ346683)头尾相接插入到真核生物表达载体pSK的多克隆位点中，构建重组质粒pSK-2PCV2；另外课题组成功构建含单个PCV2全基因组的pSK-PCV2和自身环化质粒ds-PCV2。

Gas chromatography was employed to quantify the output of metabolization,and it was found that the yield of diacetyl for the mutant UV-3 was 18.7 fold to the wild-type 10293,up to 1.045g·L~(-1).Acetoin and ethanol yields were decreased by 48.4%and 71.4%,respectively.The yield of acetate was increased by 34.6%.

利用气相色谱测定代谢产物量，分析诱变前后菌株代谢途径中碳源的流向，结果表明突变株UV-3的丁二酮产量提高18.7倍，达到1.045g/L，乙偶姻产量降低48.4%，乙醇产量降低71.4%，乙酸产量提高34.6%，且遗传性质稳定。

Enterobacter aerogenes was irradiated by He-Ne laser to optimize the laser mutagenesis condition, and to test the heredity, aciduric and hydrogen-producing potential of the mutant.

运用He-Ne激光辐照产气肠杆菌，对激光诱变参数进行优化，考察了突变株的遗传稳定性、耐酸性和产氢特性。

Enterobacter aerogenes was irradiated by He-Ne laser to optimize the laser mutagenesis condition, and to test the heredity, aciduric and hydrogen-producing potential of the mutant. An aciduric mutant with steady hydrogen-producing capability, which was able to grow at acidic pH of 3.0, was obtained. Its capability of hydrogen production was measured in the batch culture experiment.

闻建平，陈宇，刘铭辉(天津大学化工学院生物工程系，天津300072)摘要：运用He—Ne激光辐照产气肠杆菌，对激光诱变参数进行优化，考察了突变株的遗传稳定性、耐酸性和产氢特性结果筛选到一株遗传性状稳定的高产氢突变株，具有良好的耐酸性，在pH值3.0 时仍能生长。

A mutant,designated as UV-3,was selected from wild-type Enterobacter aerogenes 10293 by application of UV irradiation in combination with cultivation in high glucose medium,leucine medium and diacetyl medium.

以产气肠杆菌(Enterobacter aerogenes，CICC 10293)为出发菌株，采用紫外线诱变，并结合亮氨酸平皿和丁二酮平皿筛选方法，获得耐高浓度底物-葡萄糖的高产丁二酮突变菌株，命名为UV-3。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。