排序方式: 共有176条查询结果,搜索用时 15 毫秒
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采用制备得到的菌丝体表面分子印迹吸附剂;系统研究了菌丝体表面分子印迹吸附剂对模板金属离子的吸附选择性。结果表明:与非印迹吸附剂相比;以Ni+为模板制备的菌丝体表面分子印迹吸附剂;对Ni+、Cu+与Cr3+的吸附速率和吸附容量都有较大幅度的提高。对于含有Ni+的金属离子混合溶液;菌丝体表面分子印迹吸附剂对Ni+的吸附容量和选择性都比另一种金属离子(如Cr3+和Cu+)明显提高;与非印迹吸附剂相比;印迹吸附剂对非模板金属离子Cr3+和Cu+的选择性明显降低。 相似文献
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固定化克雷伯氏菌降低发酵液中残留甘油浓度 总被引:1,自引:0,他引:1
研究了采用海藻酸钠固定化克雷伯氏菌降低发酵液中的残留甘油浓度.与游离细胞相比,固定化细胞有利于固液分离,且对甘油浓度的降低效果也略好.培养16 h的发酵液中残留甘油浓度降低了91%.考察了固定化条件对降低残留甘油浓度的影响,确定了固定化最佳条件为:菌体∶Na-alginate=1∶10(质量体积比),3% Na-alginate,4% CaCl2,固定化24 h;固定化处理后可以提高发酵液中的1,3-丙二醇浓度.室温培养固定化细胞的实验效果与37 ℃培养相差不大.动态培养固定化细胞38 h,残留甘油浓度降低了82.4%,固定化细胞可以重复使用.通过固定化细胞处理可以减小甘油对蒸馏1,3-丙二醇时产生的影响,从而提高1,3-丙二醇的纯度和收率. 相似文献
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采用单甲氧基聚乙二醇(mPEG)修饰重组人粒细胞集落刺激因子rhG CSF,考察了各因素对蛋白质平均修饰度及体外生物活性的影响,并对修饰产物的稳定保存条件进行了初步探讨. 通过四因素四水平正交法和单因素实验结合,优化修饰条件为:PEG与G CSF摩尔比为25:1, pH 7.6的硼酸盐缓冲环境,反应时间40 min,反应温度22℃. 在此条件下,PEG-G-CSF的平均修饰度为50%,活性可保留40%左右. 研究还发现,不同的添加剂影响PEG-G-CSF的保存稳定性,人血清白蛋白和甘露醇是两种效果最好的保护剂,在它们的存在下,PEG-G-CSF溶液在4℃放置一个月后活性保留92%,三个月后保留51%. 相似文献
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Synthesis of Vitamin A Esters by Immobilized Candida sp. Lipase in Organic Media 总被引:1,自引:0,他引:1 下载免费PDF全文
YINChunhua 《中国化学工程学报》2006,14(1):81-86
Vitamin A ester was synthesized in organic solvents with immobilized lipase from Candida sp. The types of lipases, influences of solvent, the molar ratio of substrates, the reaction temperature and the water activity in the reaction were studied in detail in order to obtain the optimum conditions for Vitamin A palmitate synthesis. In a system of hexane, 100mg immobilized Candida sp. lipase was used in the presence of 1.2mmol vitamin A acetate and 3.6mmol palmitic acid. The yield of vitamin A palmitate reached 81% in 12h at 25℃. The immobilized Candida sp. lipase was prepared by adsorbing Cand/da sp. fermentation broth on pretreated textile and could be reused for at least six batches. 相似文献
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The adsorption properties of chitin adsorbent from mycelium of fermentation industries for the removal of heavy metal ions were studied.The result shows that the chitin adsorbent has high adsorption capacity for many heavy metal ions and Ni^2 in citric acid.The influence of pH was significant:When pH is higher than 4.0,the high adsorption capacity is obtained.otherwise H^ ion inhibits the adsorption of heavy metal ions.The comparison of the chitin adsorbent with some other commercial adsorbents was made,in which that the adsorption behavior of chitin adsorbent is close to that of commercial cation exchange adsorbents,and its cost is much lower than those commercial adsorbents. 相似文献
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将丙烯酸与透明质酸钠盐共聚制备了新型聚丙烯酸凝胶,对凝胶性质进行了测定。当丙烯酸添加量为6 mL、交联剂与单体摩尔比为0.015、透明质酸添加量为0.18 g时,凝胶有最好耐盐性及凝胶强度,在0.9%质量分数NaCl溶液中这种接枝共聚物的吸水率为122.695 g/g,在磷酸缓冲液中的吸水率为90.298 g/g;同时凝胶的机械强度也有了明显的改善,达到401.485kPa。添加透明质酸后所得凝胶有更好的耐盐性且透明度好,适于应用于眼科材料。 相似文献
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