响应面法优化广金钱草中总黄酮的酶法提取工艺

目的 采用响应面法优化广金钱草中总黄酮的酶法提取工艺.方法 在单因素试验的基础上,根据Box-Behnken设计原理,采用四因素三水平响应面分析方法,考察酶解时间、温度、酶用量和pH值对总黄酮得率的影响,建立二次多项式回归方程的预测模型,绘制以总黄酮含量为响应值的等高线图和响应曲面,讨论各因素间的交互作用.结果 确定了酶法提取工艺的最佳参数为:以60％乙醇提取、料液比为1∶50、0.23％纤维素酶、酶解1.49 h、酶解温度为30.55℃、pH5.52;实际测得总黄酮的得率为6.560 mg·g-1,与预测值6.481 mg·g-1相近.结论 酶法提取广金钱草中总黄酮的反应条件温和,可避免破坏有效成分的结构;优选的工艺稳定可行,提高了提取效率.     

Physiological studies on endorhizospheric establishment of Azotobacter chroococcum in wheat

Ten strains of Azotobacter chroococcum were studied for their ability to invade the endorhizosphere of wheat. Strain W‐5 exhibited ability to invade endorhizosphere as shown in the microscopic observations. This strain was compared with the strain OA‐3 which did not invade the endorhizosphere zone. Strain W‐5 showed higher production of cellulase and pectinase than OA‐3. Both the strains induced defense enzymes in the host plant. However, induction of peroxidase and phenylalanine ammonia lyase activities (PAL) was higher in OA‐3 than W‐5. Quantitative differences in flavonoid like compounds obtained from root extracts and root exudates of plants inoculated with these strains were observed. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

正交试验优选蒸制黄芩的纤维素酶辅助提取工艺

目的:优选蒸制黄芩的纤维素酶辅助提取工艺。方法:以黄芩苷和汉黄芩苷的提取率之和为指标,以纤维素酶用量、温度、pH值、时间为考察因素,采用正交试验法优选最佳提取工艺。结果:最佳提取工艺为纤维素酶用量为15U.g-1药材,温度50℃,时间7h,pH4.8。在该提取条件下,黄芩苷和汉黄芩苷的提取率分别为8.44%和2.62%。结论:纤维素酶辅助提取法优于传统的水煎煮法,为提取黄芩苷和汉黄芩苷的有效工艺,可明显提高黄芩药材的利用率。     

银杏黄酮的酶法提取工艺研究

本文研究了银杏黄酮的酶法提取工艺，银杏叶原料经纤维素酶预处理后浸提，总黄酮得率显著提高，得率可达到2．01％，其酶解过程的最优参数为：料液中酶浓度为0．125g/L，酶与底物配比为1：1200，酶解温度45℃，自然pH值，酶解时间2h。     

响应曲面法优化银杏叶萜内酯的纤维素酶辅助提取工艺

采用响应曲面法对银杏叶中萜内酯的纤维素酶辅助提取工艺过程进行了研究。在单因素实验基础上根据中心组合实验设计原理,采用4因素5水平的响应曲面分析法对提取工艺进行了优化。通过响应曲面实验及回归分析得出最佳工艺条件为:纤维素酶浓度为20.00U.g-1GBL,酶解温度45℃,酶解时间2.5h,pH4.5,预测总萜内酯的提取率为0.40%。经验证,采用酶法辅助提取工艺时,总萜内酯提取率为0.40%,相对单一乙醇提取法(0.24%)提高了约66.67%。表明由响应曲面法获得的二次模型方程能较好地预测实验结果及优化条件。     

Relative saccharification of waste paper during successive treatment with garden snail (Cornu aspersum) cellulase

The negative effect of solid waste on the environment is a topical issue effecting the global population. Waste paper is a major component of organic solid waste and cellulose a structural component of waste paper is a suitable biopolymer that could be resolved into glucose, a fermentable sugar. Also of concern to many sections of the farming community is the negative effect of garden snails on plants and fruits. When consumed by snails the cellulose section of plant materials can be hydrolysed by an enzyme system called cellulase into glucose which then is utilized as a resource of energy. Cellulase enzymes extracted from garden snails were incubated with seven different waste paper materials during ten successive incubating periods. Different sugar releasing patterns were constructed during the saccharification of the various paper materials indicating the different structural compositions of these paper materials. Foolscap paper showed the highest relative susceptibility for snail cellulase catalysed saccharification followed by brown envelope paper. The lowest amount of sugar was released during the degradation of newspaper and Pick ń Pay advertising paper.     

纤维素酶提取无患子总皂苷的正交设计实验优选

目的:优选纤维素酶提取无患子中总皂苷的最佳工艺。方法:运用正交设计实验方法步骤,以加入酶量、溶液pH值、酶提温度以及酶提时间作为4大影响提取率大小的因素,确定最佳的提取工艺。结果:最佳纤维素酶提取工艺:加入酶量为0.015%,pH值为4,50℃水浴酶提取2 h,测得平均提取率为38.98%。结论:纤维素酶提取法操作简单,稳定,提取率高。     

纤维素酶提高苦瓜降血糖有效物质含量的研究

目的:利用纤维素酶对苦瓜进行水解,来提高苦瓜降血糖有效物质含量.方法:利用纤维素酶在不同条件下对苦瓜进行水解,确定最佳实验条件.结果:温度为50℃,pH为4.3～4.4的条件下,反应72h,纤维素酶对苦瓜进行水解的效果最好.结论:纤维素酶在本实验条件下可提高苦瓜降血糖有效物质含量.     

An electrophoretic karyotype of the cultivated mushroom —Agaricus bisporus

Thirteen chromosomal-sized DNA bands of the cultivated mushroom Agaricus bisporus have been resolved using the method of clamped homogeneous electric field (CHEF) electrophoresis. Using chromosome size standards from Schizosaccharomyces pombe, Saccharomyces cerevisiae and Candida albicans, the estimated size of the chromosomal DNAs ranged from 3.5 to 1.2 megabase pairs (Mb). By Southern hybridization with homologous gene probes, the chromosomal location of cellulase and laccase genes have been mapped. In addition, rDNA has been assigned to chromosomal bands using a heterologous gene probe. Genomic rearrangement is suggested in the commercial heterokaryon, as indicated by the presence of non-comigrating homologous chromosomes, identified by a number of probes for particular DNA sequences.