贞芪扶正泡腾片的辅料处方优选的研究

目的 优选贞芪扶正泡腾片的处方。方法 本实验用酒石酸为酸源,NaHCO₃为碱源,崩解时限、口感等为考察指标,单因素试验筛选酸碱比例,通过正交试验筛选酸碱总量、药粉总量以及崩解剂,采用HPLC测定泡腾片中特女贞苷的含量。结果 贞芪扶正泡腾片的最佳处方：药粉15%、酒石酸17.78%、NaHCO₃ 22.22%、PEG6000 11.11%、PVPP 3.5%、α-乳糖30.14%、硬脂酸镁0.25%,以蒸馏水作为润湿剂,用酸碱分开的方式制粒。所得泡腾片口感好、硬度适中、片重差异小、脆碎度、崩解时限以及含量符合规定。结论 该处方合理,制成的泡腾片符合规定。     

菠萝蜜多糖提取工艺优化及初步鉴定

以菠萝蜜果肉为试验原料,在单因素试验基础上,利用三因素三水平的Box-Benhnken中心组合试验和响应曲面法优化液料比、提取时间和提取温度对多糖类物质的提取工艺和建立数学模型,并对制备的多糖进行初步鉴定。结果表明,二次方程模型拟合试验数据效果显著,菠萝蜜多糖提取工艺为:液料比为30∶1,提取时间为2.5 h,提取温度为90℃,验证试验得率为6.18%,多糖初步鉴定结果显示,菠萝蜜精制多糖中总糖含量为31.6%,不含有还原糖、含有微量多酚类物质(含量为0.6%)。     

一株抗马铃薯坏疽病莫海威芽孢杆菌(Bacillusmojavensis ZA1)培养条件的优化

为了提高生防菌株莫海威芽孢杆菌(Bacillus mojavensis ZA1)液体发酵的生物量,利用单因素试验设计与响应曲面试验设计相结合的方法对ZA1摇瓶发酵条件进行了优化。结果表明,ZA1的最佳培养基配比为氯化铵14.25 g、玉米粉19 g、马铃薯237 g、水1000 mL,最佳发酵条件为pH 7.7、培养温度28℃、转速180 r/min及发酵时间36 h,ZA1优化后活菌数为4.12×10¹⁰ CFU/mL。通过中心组合试验设计确定ZA1在10 L发酵罐中的最佳溶氧量为60%和转速为180 r/min;最优条件下,发酵ZA1的放罐时间确定为36 h,活菌数达到1.59×10¹¹ CFU/mL。该结果为利用ZA1开发生防制剂奠定了基础。     

采用环介导等温扩增法(LAMP)快速检测苹果根结线虫

为高效、简便、快速地对我国进境植物检疫性有害生物名录中的非中国种—苹果根结线虫Meloidogyne mali进行检疫,通过比较Gen Bank中根结线虫相关序列,以苹果根结线虫28S r DNA非保守区域序列设计环介导等温扩增(loop-mediated isothermal amplification,LAMP)的特异性引物,并优化反应条件,建立一种可快速检测苹果根结线虫的LAMP检测体系。结果显示:d NTPs浓度为0.4 mmol/L、Mg~(2+)浓度为5.0 mmol/L、不添加甜菜碱、反应时间为60 min时,LAMP检测体系扩增效率最高;用琼脂糖凝胶电泳、SYBR Green I染色和LFD试纸均能检测到苹果根结线虫的扩增产物。所建立的LAMP检测体系能够从10种供试植物线虫种群中特异性地检测出苹果根结线虫,灵敏度为1/20 000条线虫DNA,比常规PCR灵敏度高10倍。表明所建立的苹果根结线虫LAMP快速检测体系可用于我国口岸进境植物中苹果根结线虫检疫。     

Responses of gross primary productivity to different sizes of precipitation events in a temperate grassland ecosystem in Inner Mongolia,China

Changes in the sizes of precipitation events in the context of global climate change may have profound impacts on ecosystem productivity in arid and semiarid grasslands. However, we still have little knowledge about to what extent grassland productivity will respond to an individual precipitation event. In this study, we quantified the duration, the maximum, and the time-integrated amount of the response of daily gross primary productivity(GPP) to an individual precipitation event and their variations with different sizes of precipitation events in a typical temperate steppe in Inner Mongolia, China. Results showed that the duration of GPP-response(τR) and the maximum absolute GPP-response(GPPmax) increased linearly with the sizes of precipitation events(Pes), driving a corresponding increase in time-integrated amount of the GPP-response(GPPtotal) because variations of GPPtotal were largely explained by τR and GPPmax. The relative contributions of these two parameters to GPPtotal were strongly Pes-dependent. The GPPmax contributed more to the variations of GPPtotal when Pes was relatively small(20 mm), whereas τR was the main driver to the variations of GPPtotal when Pes was relatively large. In addition, a threshold size of at least 5 mm of precipitation was required to induce a GPP-response for the temperate steppe in this study. Our work has important implications for the modeling community to obtain an advanced understanding of productivity-response of grassland ecosystems to altered precipitation regimes.     

Nutrient efficacy of microalgae as aquafeed additives for the adult black tiger prawn,Penaeus monodon

This study used a small amount of several lyophilized microalgae (5% of dry weight in aquafeed) to feed adult black tiger prawns Penaeus monodon for 4 weeks, aiming to promote prawn health and nutritional level. Apart from slight increases in ash content, chlorophyll and β‐carotene in the microalgae‐added feeds, there was no difference from the commercial diet in their biochemical composition. After 28 days of feeding, prawn body length, body weight, condition index and also total amount of fatty acids and amino acids of the flesh (2nd abdominal segment) were not affected by microalgae additives as compared with the control commercial diet‐fed group (P > 0.05). Prawns fed the microalgae diets, however, had a relatively better survival rate than those fed the commercial control diet, although no statistical significance was detected in any except for the diatom Melosira sp. The elevated survival rate was concomitant with a higher phagocytosis rate and superoxide dismutase (SOD) activity in the immune response analysis, and significantly a higher astaxanthin content detected in the tail muscle of microalgae diet‐fed prawns (5.36–10.78 ng of astaxanthin per gram of muscle DW). These findings demonstrated that low‐inclusion microalgal additives in prawn diets over a short feeding period (4 weeks) can result in healthier adult prawn, and hence could contribute to the development of an optimized feeding strategy for prawn aquaculture close to harvesting.     

Cryptocaryon irritans recombinant proteins as potential antigens for sero‐surveillance of cryptocaryonosis

Cryptocaryonosis is a major problem for mariculture, and the absence of suitable sero‐surveillance tools for the detection of cryptocaryonosis makes it difficult to screen Cryptocaryon irritans‐infected fish, particularly asymptomatic fish. In this study, we proposed a serum‐based assay using selected C. irritans proteins to screen infected and asymptomatic fish. Eight highly expressed genes were chosen from an earlier study on C. irritans expressed sequence tags and ciliate glutamine codons were converted to universal glutamine codons. The chemically synthesized C. irritans genes were then expressed in an Escherichia coli expression host under optimized conditions. Five C. irritans proteins were successfully expressed in E. coli and purified by affinity chromatography. These proteins were used as antigens in an enzyme‐linked immunosorbent assay (ELISA) to screen sera from experimentally immunized fish and naturally infected fish. Sera from both categories of fish reacted equally well with the expressed C. irritans recombinant proteins as well as with sonicated theronts. This study demonstrated the utility of producing ciliate recombinant proteins in a heterologous expression host. An ELISA was successfully developed to diagnose infected and asymptomatic fish using the recombinant proteins as antigens.     

京海黄鸡促性腺激素释放激素受体基因密码子特性分析

为了了解鸡促性腺激素释放激素受体(gonadotropin releasing hormone receptor, GnRHR)基因的密码子特性,以便于为GnRHR基因的表达选择合适的外源表达系统,本研究使用在线工具CUSP、CHIPS及CodonW软件对鸡GnRHR基因的密码子特性进行分析,并与鸡、模式动物基因组和其他动物GnRHR基因密码子特性进行比较.结果显示,京海黄鸡GnRHR基因的ENc值较小,具有较强的密码子偏好性,且偏好以G/C结尾的密码子, GnRHR基因CDS序列中,GC含量大于AT含量;CodonW软件计算结果表明,京海黄鸡GnRHR基因密码子中,密码子GCC、ATC、CTC、CTG、CGC、CGG、AGC、TCC和GTG(RSCU>2)偏好性较强,且均以G/C结尾.对31条鸡基因分析表明鸡偏好密码子中有12种G/C结尾的密码子.与大肠杆菌、酵母菌和小鼠基因组密码子使用频率比较显示,京海黄鸡GnRHR基因密码子偏好性与3种生物相差很大,不适合进行外源表达.与其他动物GnRHR基因密码子偏好性比较显示,禽类GnRHR基因偏好含有或以G/C结尾的密码子,而其他物种的GnRHR基因无强烈的偏好性.聚类分析结果表明,亲缘关系近的物种之间倾向于拥有相同的密码子偏好性.     

犬瘟热病毒N蛋白基因融合蛋白原核表达条件的优化与蛋白纯化

[目的]提高犬瘟热病毒N蛋白基因在大肠杆菌中表达可溶性GST融合蛋白的含量.[方法]研究诱导剂(IPTG)的最佳加入时间、诱导剂(IPTG)浓度、诱导时间以及不同温度条件对GST - CDV N融合蛋白表达的影响,获得在大肠杆菌中的最佳的表达条件,然后再在最佳条件下大量的表达,用GST - Sepharose 4B亲和层析柱对GST - CDV N融合蛋白进行纯化,得到最大量的可溶性融合蛋白,并对蛋白含量进行测定.[结果]大肠杆菌BL21 (DE3)转化菌在37℃培养3.5 h(OD600 =1.314)时,加入IPTG使终浓度为1 mmol/L,然后在27℃诱导8h,GST - CDV N融合蛋白可溶性表达量最高,达到0.862 mg/mL.[结论]确定了犬瘟热病毒N蛋白基因的优化表达条件,为犬瘟热病毒分子免疫学诊断和亚单位疫苗的研制奠定了基础.     

香蕉麻预处理脱胶优化研究

天然香蕉麻纤维存在“粗、硬、脆”等问题,影响到常规与高档纺织品的开发;为提高天然香蕉麻可纺性能．在系统分析香蕉麻化学成分的基础上。采用正交试验方法对酶预处理脱胶与双氧水预处理脱胶工艺进行了优化。结果表明,以胶质溶除率评定,酶预处理下最佳脱胶工艺条件是：氢氧化钠浓度8g／L,精炼时间3h,酶处理时间6h;双氧水预处理最佳脱胶工艺条件是：pH9,温度50℃,处理时间30min。