The seed germination and tomato seedling tests showed that Bacillus subtilis SL-13 could promote the sprouting and seedling growth of tomato.The fresh and dry weight of tomato seedlings increased 42.86%and 18.75%,resp...The seed germination and tomato seedling tests showed that Bacillus subtilis SL-13 could promote the sprouting and seedling growth of tomato.The fresh and dry weight of tomato seedlings increased 42.86%and 18.75%,respectively.The control efficacies of the SL-13 to tomato Rhizoctonia rot were 20.65%and 35.23%in the greenhouse and field,respectively.The growth of the plant-pathogenic fungus Rhizoctonia solani was considerably inhibited in the presence of the strain SL-13 culture supernatant.The main antifungal protein was detected to be chitinase through vitro assay.The chitinase was purified with DEAE-Sepharose fast flow ion exchange column chromatography and Sephadex G-75 gel filtration for further characterization.The optimal pH and temperature for the chitinase activity were 7.0 and 50°C,respectively.It was demonstrated that the enzyme was stable at pH 5-9 and 40-60°C.70%of the enzyme activity was retained when incubated at 121°C and 0.11 MPa for 20 min,and the enzyme was not sensitive to protease K and ultraviolet radiation.Thus it is suitable for effective biological control in relatively unstable environment.展开更多
采用改良硫酸铵盐析法从鸡胆汁中分离鸡分泌型免疫球蛋白A（SIgA）．Macro-prep High Q阴离子交换柱层析提纯，经二次过柱后获得的鸡SIgA浓度达22mg／mL。SDS-聚丙烯酰胺凝胶电泳检测表明，重链分子质量为63～64ku，轻链为26～28ku，J链...采用改良硫酸铵盐析法从鸡胆汁中分离鸡分泌型免疫球蛋白A（SIgA）．Macro-prep High Q阴离子交换柱层析提纯，经二次过柱后获得的鸡SIgA浓度达22mg／mL。SDS-聚丙烯酰胺凝胶电泳检测表明，重链分子质量为63～64ku，轻链为26～28ku，J链约16ku。用纯化的鸡SIgA免疫兔，所得的抗血清经双向琼脂扩散，证明兔抗鸡SIgA血清效价达1：128。展开更多
基金Supported by the National Natural Science Foundation of China（20776017） the Xinjiang Uygur Autonomous Region High-tech Research and Development Project（20081108）+1 种基金 the Fok Ying Tung Education Foundation（101071） the Xinjiang Bingtuan Key Science and Technology Industry Project（2008GG24）
文摘The seed germination and tomato seedling tests showed that Bacillus subtilis SL-13 could promote the sprouting and seedling growth of tomato.The fresh and dry weight of tomato seedlings increased 42.86%and 18.75%,respectively.The control efficacies of the SL-13 to tomato Rhizoctonia rot were 20.65%and 35.23%in the greenhouse and field,respectively.The growth of the plant-pathogenic fungus Rhizoctonia solani was considerably inhibited in the presence of the strain SL-13 culture supernatant.The main antifungal protein was detected to be chitinase through vitro assay.The chitinase was purified with DEAE-Sepharose fast flow ion exchange column chromatography and Sephadex G-75 gel filtration for further characterization.The optimal pH and temperature for the chitinase activity were 7.0 and 50°C,respectively.It was demonstrated that the enzyme was stable at pH 5-9 and 40-60°C.70%of the enzyme activity was retained when incubated at 121°C and 0.11 MPa for 20 min,and the enzyme was not sensitive to protease K and ultraviolet radiation.Thus it is suitable for effective biological control in relatively unstable environment.
文摘对土鳖虫水浸醇沉提取物2号样品进行了离子交换柱层析,得组分Ⅰ、Ⅱ、Ⅲ。实验结果表明,组分Ⅲ的溶栓活性明显高于组分Ⅰ和组分Ⅱ,其蛋白质含量为88.9%,分子量约为38,018,效价为313 UK/mg,比活力为352 UK/mg蛋白。将组分Ⅲ再进行凝胶过滤柱层析,得组分Ⅳ、Ⅴ、Ⅵ。组分Ⅵ的生物活性高于组分Ⅳ和组分Ⅴ,蛋白质含量为89.3%,电泳呈现两条带,分子量约为34,623和39,811,效价为77 UK/mg,比活力为86 UK/mg蛋白。将组分Ⅵ进行反相高效液相色谱柱层析,收集保留时间为17 m in的洗脱峰,得到土鳖虫纯蛋白质,呈白色絮状,极易溶于水。再一次用反相高效液相色谱检查其纯度,保留时间为17.073 m in,无杂质峰。纤溶活性实验结果表明,组分Ⅵ既有直接降解纤维蛋白的作用,同时也有纤溶酶原激活剂样作用。
文摘采用改良硫酸铵盐析法从鸡胆汁中分离鸡分泌型免疫球蛋白A（SIgA）．Macro-prep High Q阴离子交换柱层析提纯，经二次过柱后获得的鸡SIgA浓度达22mg／mL。SDS-聚丙烯酰胺凝胶电泳检测表明，重链分子质量为63～64ku，轻链为26～28ku，J链约16ku。用纯化的鸡SIgA免疫兔，所得的抗血清经双向琼脂扩散，证明兔抗鸡SIgA血清效价达1：128。
文摘以蝾螺内脏为材料,通过硫酸铵沉淀分级分离、SephadexG 200分子筛柱层析和两次DEAE SephadexA 50离子交换柱层析纯化,获得聚丙烯酰胺凝胶电泳单一纯的N 乙酰 β D 氨基葡萄糖苷酶酶制剂.纯酶的比活力为1448U·mg-1.酶的紫外特征吸收峰在275nm处,内源荧光发射峰在340nm处.以对 硝基苯 N 乙酰 β D 氨基葡萄糖为底物,研究酶催化底物水解的反应动力学,结果表明:酶的最适pH为4.5,最适温度为45℃.该酶在pH3.5～6.0区域较稳定,而在pH>7能很快失活;在40℃以下处理30min,酶活力保持稳定,高于40℃,酶稳定性较差,很快失活.酶促反应动力学符合米氏双曲线方程,测得米氏常数Km为3.13mmol·L-1,最大反应速度Vm为17.68μmol·L-1·min-1.
