Loofa immobilized Bacillus sp. DSM 2523 as a whole cell biocatalyst for production of cyclodextrin glucanotransferase in an airlift reactor with a net draft tube

Cyclodextrin glucanotransferase (CGTase) production was studied using loofa-immobilized Bacillus sp. DSM 2523 and starch substrate. The bacterial cells from 2- and 4-day old cultures were used in the flask studies. Loofa and chitosan were added for cell immobilization and cell flocculation, respectively, and different treatments were considered according to the timing of their addition. The cell responses were evaluated for their degree of cell immobilization and level of CGTase activity. With the use of the selected treatment, testing was carried out in an airlift reactor with a net draft tube having specific geometric properties. The cell capacity for reusability also was examined. The production of CGTase was higher in the second cycle in the reactor operated at 0.25 vvm where the enzyme activity reaching 0.20?U/ml within 2?h. In the flask experiments, CGTase activity reached 0.23?U/ml after 19?h in the second cycle.     

豚草中绿原酸的测定及提取剩余物的生物转化

采用超声波法辅助提取、HPLC测定的方法,研究了豚草不同部位绿原酸的含量.并与烟草、金银花和几种南京郊区常见杂草的绿原酸含量进行了比较,将提取剩余物用间型脉孢菌进行了生物转化.实验结果表明,豚草各部位的绿原酸含量以叶最多,为1.160 mg/g;花和茎次之,分别为0.559和0.494 mg/g;豚草叶绿原酸以7月份含量最高.在50℃时用超声波辅助提取,作用时间以20 m in为宜.用间型脉孢菌转化提取剩余物,物料经生物转化后,富含纤维素酶、蛋白酶和类胡萝卜素,其中纤维素酶中CMC酶活性为5 503.9 U/g,蛋白酶活性为7 926.4 U/g,类胡萝卜素含量为126.6μg/g.提取酶和类胡萝卜素后的物料可作为生产有机肥的原料,使物料得到全部利用.     

活性干酵母对无机硒生物转化作用的研究

对活性干酵母的耐Se、富Se性能作了探讨,并初步研究了酵母转化无机Se为有机Se的营养与环境条件．结果表明活性干酵母具有很强的耐Se、富Se能力,是生产富Se酵母的好菌种;无机Se添加量和培养时间等是影响活性干酵母Se转化能力的主要因素,在适宜的摇瓶发酵条件下富Se酵母干重、Se含量和转化率分别可达15.8g/L,790.0μg/g和83.2%．     

Pharmacological Evaluation and Preliminary Pharmacokinetics Studies of a New Diclofenac Prodrug without Gastric Ulceration Effect

Long-term nonsteroidal anti-inflammatory drugs (NSAIDs) therapy has been associated with several adverse effects such as gastric ulceration and cardiovascular events. Among the molecular modifications strategies, the prodrug approach is a useful tool to discover new safe NSAIDs. The 1-(2,6-dichlorophenyl)indolin-2-one is a diclofenac prodrug which demonstrated relevant anti-inflammatory properties without gastro ulceration effect. In addition, the prodrug decreases PGE₂ levels, COX-2 expression and cellular influx into peritoneal cavity induced by carrageenan treatment. Preliminary pharmacokinetic studies have shown in vivo bioconversion of prodrug to diclofenac. This prodrug is a new nonulcerogenic NSAID useful to treat inflammatory events by long-term therapy.     

生物转化法制取琥珀酸及其衍生物的前景分析

介绍了琥珀酸的主要应用领域。进一步分析了生物转化法生产琥珀酸的成本结构,生物转化法不仅具有环保、节约能源的优点,而且使琥珀酸的生产摆脱了石油产品的限制,从而使低成本、大规模制取琥珀酸成为可能。这些将为生物转化法制取琥珀酸的研究发展和战略决策提供参考资料。