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Search Results: 1 - 10 of 62699 matches for " LIANG Ying-Ping "
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Effect of branched-chain amino acids, valine, isoleucine and leucine on the biosythesis of bitespiramycin 4"-O-acylspiramycins
Li, Zhen-Lin;Wang, Yong-Hong;Chu, Ju;Zhuang, Ying-Ping;Zhang, Si-Liang;
Brazilian Journal of Microbiology , 2009, DOI: 10.1590/S1517-83822009000400003
Abstract: bitespiramycin, a group of 4"-o-acylated spiramycins with 4"-o-isovalerylspiramycins as the major components, was produced by recombinantspiramycin-producing strain streptomyces spiramyceticus harboring a 4"-o-acyltransferase gene. the experiment was initially performed in synthetic medium with 0.5 g l-1 valine, isoleucine or leucine feeding at 36 h cultivation. when valine was fed, the biological titer of bitespiramycin was 45.3% higher than that of the control group, but the relative content of total isovalerylspiramycin components decreased by 22.5%. in the case of ilecine, the biological titer of bitespiramycin and the total isovalerylspiramycins alone were 85% and 72.1% of the control group, respectively. in contrast, the relative content of other acylated spiramycins increased by 54.41%. however, leucine feeding increased the relative content of total isovalerylspiramycins by 41.9% while the biological titer of bitespiramycin was nearly equal to that of the control group. the improvement effect of leucine on the biosynthesis of isovalerylspiramycins was further confirmed by feeding of 2.0 g l-1 leucine to the culture with complex medium. after batch feeding with a total amount of 2.0 g l-1 leucine to the culture from 70 h to 90 h, the biological titer of bitespiramycin was almost unreduced, and the final relative content of total isovalerylspiramycins increased from 31.1% to 46.9%.
Comparison of Two Methods for Extracting Total RNA from Citrus Leaves

JIANG Juan,XUE Jiao-liang,XIE Ying-ping,

热带亚热带植物学报 , 2009,
Abstract: 为了简便、快速提取高质量的柑橘(Citrus reticulata Banco)叶片总RNA,采用TRlzol法,对北京天根公司RNAplant Reagent和日本TaKaRa公司RNAiso Reagent两种RNA提取试剂进行比较并适当改进.结果表明:通过琼脂糖凝胶电泳,使用TaKaRa公司试剂提取的总RNA28S和18S条带清晰,紫外分光光度计检测分析A260/A280为1,820,A260,A230为2.088,RNA的浓度为2.840 μg μl-1,用于RT-PCR反应可成功克隆柑橘β-actin看家基因228 bp片段;采用天根公司试剂,琼脂糖凝胶电泳显示RNA带型较模糊,紫外分光光度计检测分析A260/A280为1.464,A260/A230为1.603,RNA的浓度为2.020 μg μl-1,达不到RNA的标准.TaKaRa公司RNAiso Reagent试剂提取的柑橘叶RNA纯度和完整性较好,能用于Northern杂交、cDNA文库的建立及基因克隆等分子生物学实验,为柑橘的进一步分子生物学研究奠定了基础.
Regulatory effects of ammonium ions on the biosynthesis of meilingmycin

WANG Ping,ZHUANG Ying-ping,CHU Ju,ZHANG Si-liang,

微生物学报 , 2005,
Abstract: Based on the effects of different ammonium sulfate concentrations on meilingmycin biosynthesis, the results show that lower concentration of ammonium ions stimulates the biosynthesis of meilingmycin, while the concentration of higher than 5mmol/L inhibits the mycelial growth and the biosynthesis of the products. However, the sugar consumption rate increases with the elevating concentration of ammonium sulfate. On this basis, six enzymes, which are greatly related to the meilingmycin biosynthesis and the glucose metabolism, were measured and analyzed during the meilingmycin fermentation process. The results suggest that glucose_6_phosphate dehydrogenase, citrate synthase, succinate dehydrogenase and fatty acid synthase are stimulated by higher concentration of ammonium ions, while valine dehydrogenase and methylmalonyl_CoA carboxyltransferase are inhibited. From the results it follows that ammonium ions favors primary metabolism, that is, the HMP passway and the TCA circle is enhanced, as well as the source of the precursors for the biosynthesis of meilingmycin is restricted, which bring about the lower production of meilingmycin.
High Characteristic Temperature InGaAsP/InP Tunnel Injection Multiple-Quantum-Well Lasers

WANG Yang,QIU Ying-Ping,PAN Jiao-Qing,ZHAO Ling-Juan,ZHU Hong-Liang,WANG Wei,

中国物理快报 , 2010,
Support Vector Regression Model of Chlorophyll-a during Spring Algal Bloom in Xiangxi Bay of Three Gorges Reservoir, China  [PDF]
Hua-Jun Luo, De-Fu Liu, Ying-Ping Huang
Journal of Environmental Protection (JEP) , 2012, DOI: 10.4236/jep.2012.35052
Abstract: To study the relationship between chlorophyll-a and environmental variables during spring algal bloom in Xiangxi Bay of Three Gorges Reservoir, the support vector regression (SVR) model was established. In surveys, 11 stations have been investigated and 264 samples were collected weekly from March 4 to May 13 in 2007 and February 16 to May 10 in 2008. The parameters in SVR model were optimized by leave one out cross validation. The squared correlation coefficient R2 and the cross validated squared correlation coefficient Q2 of the optimal SVR model are 0.8202 and 0.7301, respectively. Compared with stepwise multiple linear regression and back propagation artificial neural network models using external validation, the SVR model has been shown to perform well for regression with the predictive squared correlation coefficient R2pred value of 0.7842 for the test set.
Analysis on Metabolic Flux Shift During Guanosine Fermentation

CAI Xian-Peng,CHEN,Shuang-Xi,CHU Ju,ZHUANG Ying-Ping,ZHANG Si-Liang,

生物工程学报 , 2002,
Abstract: Taking the typical metabolic control product-guanosine as an example, the method of metabolic flux shift investigation based on process multi-levels parameter correlation analysis was established. The metabolic pathway, multi-parameter correlation, accumulation of amino acid and organic acid during guanosine fermentation process were integratively analyzed. The metabolic flux shift from HMP to EMP was ascertained, which was assumed to be caused by the accumulation of ammonium ion. The subsequent optimization based on controlling flux distribution between EMP and HMP did improve the yield by 35% when the metabolic flux shift was prevented.
Metabolic Calculation of the Growth Phase in rHSA Fermentation

HUANG Ming-Zhi,GUO Mei-Jin,CHU Ju,HANG Hai-Feng,ZHUANG Ying-Ping,ZHANG Si-Liang,

生物工程学报 , 2000,
Abstract: The model equations of the growth phase of rHSA fermentation were derived on the base of both elemental balance and metabolic balance. The unknown parameters of the model were estimated by multivariable optimization. The model can preferably describe the relations between different macroscopic reaction rates of the process and provide the key for the high-density cultivation of Pichia pastoris.

CHEN Shuang-Xi,CAI Xian-Peng,WANG Zhong-Shi CHU Ju,ZHUANG Ying-Ping,ZHANG Si-Liang,

微生物学通报 , 2002,
Abstract: Bacillus subtilis AJ2066 was used to yield guanosine. The optimization of guanosine fermentation was studied by means of flask coupled with 50L auto-controlled fermentor. Monosodium glutamate is important to guanosine fermentation. The yield reached 31.49g/L in 50L fermentor with the medium supplemented with 1% monosodium glutamate. Hypoxanthine (Hx) can be used to synthesize guanosine directly as precursor. The yield reached 33.24g/L in 50L fermentor by supplementing 0.2% hypoxanthine during final stage of fermentation.
Application of Element and Metablism Balancing for the Cultivation Process with Streptomyces aureofaciens

FU Jiao-Long,ZHUANG Ying-Ping,HUANG Ming-Zhi,CHU Ju,ZHANG Si-Liang,

生物工程学报 , 2003,
Abstract: On the base of element and metablism balancing, the mathematical model of the cultivation process with Streptomyces aureofaciens was developed, and the unknown parameters in the model were estimated with the method of nonlinear optimization. Firstly the energetic coefficient of CTC biosynthesis was gained, which was 1.8 - 2.8 mol-ATP x C-mol(-1). The macroscopic reaction rates were predicted in the process and compared with the experimental values. The results show that the model can preferably describe the relationships between several macroscopic reaction rates in the process and can supervise the optimization of CTC fermentation process theoretically.
High-density Expression of Recombinant Porcine Insulin Precursor by Pichia pastoris

LIU Yu-Wei,HCANG Ming-Zhi,ZHUANG Ying-Ping,CHU Ju ZHANG,Si-Liang,

微生物学通报 , 2007,
Abstract: 对摇瓶和50L罐上的重组菌毕赤酵母(Pichia pastoris)表达猪胰岛素前体(PIP)的发酵过程进行了研究。摇瓶发酵中,最佳诱导周期为60 h左右,诱导期甲醇的最佳加入量为每日2.0%~2.5%。50L发酵过程分为批发酵、补料和诱导表达3个阶段。生长期(批发酵和补料阶段)细胞干重与培养时间的关系可用模型y= 0.6525e~(0.1909t)来描述。在批发酵阶段和补料阶段,流加的氨水和甘油几乎全部用来合成菌体和维持,没有其他副产物产生。诱导表达阶段流加的氨水和甲醇分别约有80%和70%被菌体利用。将摇瓶与发酵罐的实验结果进行了比较,发现摇瓶发酵的限制因子很可能是溶氧,而罐发酵的限制因子为碳源,因此,将摇瓶实验的结果放大到发酵罐时调整了控制策略,加大了甲醇的补料速率,最终PIP浓度达到1.72g/L。
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