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Optimization of biotransformation from phytosterol to androstenedione by a mutant Mycobacterium neoaurum ZJUVN-08

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2013年第2期14卷 132-143页

作者： Xiao-yan ZHANG Yong PENG Zhong-rui SU qi-he chen Hui RUAN Guo-qing he Department of Food Science and Nutrition Zhejiang University Department of Food Science and Technology School of Agriculture and BiologyShanghai Jiao Tong University

Biotransformation of phytosterol(PS) by a newly isolated mutant Mycobacterium neoaurum ZJUVN-08 to produce androstenedione has been investigated in this *** parameters of the biotransformation process were optimized using fractional factorial design and response surface *** was the sole product in the fermentation broth catalyzed by the mutant *** ZJUVN-08 *** showed that molar ratio of hydroxypropyl-β-cyclodextrin(HP-β-CD) to PS and substrate concentrations were the two most significant factors affecting androstenedione *** analyzing the statistical model of three-dimensional surface plot,the optimal process conditions were observed at 0.1 g/L inducer,pH 7.0,molar ratio of HP-β-CD to PS 1.92:1,8.98 g/L PS,and at 120 h of incubation *** these conditions,the maximum androstenedione yield was 5.96 g/L and nearly the same with the non-optimized(5.99 g/L),while the maximum PS conversion rate was 94.69% which increased by 10.66% compared with the non-optimized(84.03%).The predicted optimum conditions from the mathematical model were in agreement with the verification experimental *** is considered that response surface methodology was a powerful and efficient method to optimize the parameters of PS biotransformation process.

关键词： Phytosterol Mycobacterium neoaurum ZJUVN-08 Androstenedione Hydroxypropyl-β-cyclodextrin

Effects of proteinase A on cultivation and viability characteristics of industrial Saccharomyces cerevisiae WZ65

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第10期10卷 769-776页

作者： Hong-bo ZHANG Hai-feng ZHANG qi-he chen Hui RUAN Ming-liang FU Guo-qing he Department of Food Science and Nutrition Zhejiang University Hangzhou 310029 China

Proteinase A （PrA）, encoded by PEP4 gene, is a key enzyme in the vacuoles of Saccharomyces cerevisiae. We characterized the effects of PrA on cell growth and glucose metabolism in the industrial S. cerevisiae WZ65. It was observed that the lag phase of cell growth of partial PEP4 gene deletion mutant （36 h） and PrA-negative mutant （48 h） was significantly extended, compared with the wild type strain （24 h）（P〈0.05）, but PrA had no effect on glucose metabolism either under shaking or steady state cultivations. The logistic model was chosen to evaluate the effect of PrA on S. cerevisiae cell growth, and PrA was found to promote cell growth against insufficient oxygen condition in steady state cultivation, but had no effect in shaking cultivation. The effects of glucose starvation on cell growth of partial PEP4 gene deletion strain and PrA-negative mutant were also evaluated. The results show that PrA partial deficiency increased the adaption ofS. cerevisiae to unfavorable nutrient environment, but had no effect on glucose metabolism under the stress of low glucose. During heat shock test, at 60 ℃ the reduced cell viability rate （RCVR） was 10% for the wild type S. cerevisiae and 90% for both mutant strains （P〈0.01）, suggesting that PrA was a negative factor for S. cerevisiae cells to survive under heat shock. As temperatures rose from 60 ℃ to 70℃, the wild type S. cerevisiae had significantly lower relative glucose consumption rate （RGCR）（61.0% and 80.0%） than the partial mutant （78.0% and 98.5%） and the complete mutant （80.0% and 98.0%）（P〈0.05）, suggesting that, in coping with heat shock, cells of the PrA mutants increased their glucose consumption to survive. The present study may provide meaningful information for brewing industry; however, the role of PrA in industrial S. cerevisiae physiology is complex and needs to be further investigated.

关键词： Proteinase A (PrA) PEP4 gene Saccharomyces cerevisiae WZ65 Cell metabolism Viability

Construction of recombinant industrial Saccharomyces cerevisiae strain with bglS gene insertion into PEP4 locus by homologous recombination

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第7期9卷 527-535页

作者： qiang ZHANG qi-he chen Ming-liang FU Jin-ling WANG Hong-bo ZHANG Guo-qing he Department of Food Science and Nutrition Zhejiang University Hangzhou 310029 China

The bglS gene encoding endo-1,3-1,4-β-glucanase from Bacillus subtil＆ was cloned and sequenced in this study. The bglS expression cassette, including PGK1 promoter, bglS gene fused to the signal sequence of the yeast mating pheromone a-factor （MFals）, and ADH1 terminator with G418-resistance as the selected marker, was constructed. Then one of the PEP4 allele of Saccharomyces cerevisiae WZ65 strain was replaced by bglS expression cassette using chromosomal integration of polymerase chain reaction （PCR）-mediated homologous recombination, and the bglS gene was expressed simultaneously. The recombinant strain S. cerevisiae （SC-βG） was preliminarily screened by the clearing hydrolysis zone formed after the barley β-glucan was hydrolyzed in the plate and no proteinase A （PrA） activity was measured in fermenting liquor. The results of PCR analysis of genome DNA showed that one of the PEP4 allele had been replaced and bglS gene had been inserted into the locus of PEP4 gene in recombinant strains. Different endo-1,3-1,4-β-glucanase assay methods showed that the recombinant strain SC-βG had high endo-1,3-1,4-β-glucanase expression level with the maximum of 69.3 U/（h·ml） after 60 h of incubation. Meanwhile, the Congo Red method was suitable for the determination of endo-1,3-1,4-β-glucanase activity during the actual brewing process. The current research implies that the constructed yeast strain could be utilized to improve the industrial brewing property of beer.

关键词： Endo-1 3-1 4-β-glucanase (bglS) Gene replacement Homologous recombination Bacillus subtilis PEP4 gene Saccharomyces cerevisiae

A food-grade industrial arming yeast expressing β-1,3-1,4-glucanase with enhanced thermal stability

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第1期11卷 41-51页

作者： qin GUOt Wei ZHANG Liu-liu MA qi-he chen Ji-cheng chen Hong-bo ZHANG Hui RUAN Guo-qing he Department of Food Science and Nutrition Zhejiang University Hangzhou 310029 China Wenzhou Medical College Wenzhou 325035 China

The aim of this work was to construct a novel food-grade industrial arming yeast displaying β-1,3-1,4-glucanase and to evaluate the thermal stability of the glucanase for practical application. For this purpose, a bi-directional vector containing galactokinase （GALl） and phosphoglycerate kinase 1 （PGK1） promoters in different orientations was constructed. The β-1,3-1,4-glucanase gene from Bacillus subtilis was fused to α-agglutinin and ex- pressed under the control of the GALl promoter, α-galactosidase induced by the constitutive PGK1 promoter was used as a food-grade selection marker. The feasibility of the α-galactosidase marker was confirmed by the growth of transformants harboring the constructed vector on a medium containing melibiose as a sole carbon source, and by the clear halo around the transformants in Congo-red plates owing to the expression of β-1,3-1,4-glucanase. The analysis of β-1,3-1,4-glucanase activity in cell pellets and in the supernatant of the recombinant yeast strain revealed that β-1,3-1,4-glucanase was successfully displayed on the cell surface of the yeast. The displayed β-1,3-1,4-glucanase activity in the recombinant yeast cells increased immediately after the addition of galactose and reached 45.1 U/ml after 32-h induction. The thermal stability of β-1,3-1,4-glucanase displayed in the recombinant yeast cells was en- hanced compared with the free enzyme. These results suggest that the constructed food-grade yeast has the potential to improve the brewing properties of beer.

关键词： α-agglutinin Food-grade selection marker β-1 3-1 4-glucanase α-galactosidase Thermostability

Ammonia pyrolysis oxidation excited by nanosecond pulsed discharge:Global/fluid models hybrid solution

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Journal of Energy Chemistry 2025年第1期100卷 385-396页

作者： Mingming Zhang Hanyu Wu qi chen Jiaxin Yang Bonan Liu School of Mechanical Electronic and Control Engineering Beijing Jiaotong University China University of Petroleum

The kinetic characteristics of plasma-assisted oxidative pyrolysis of ammonia are studied by using the global/fluid models hybrid solution ***,the stable products of plasma-assisted oxidative pyrolysis of ammonia are *** results show that the consumption of NH3/O2and the production of N2/H2change linearly with the increase of voltage,which indicates the decoupling of nonequilibrium molecular excitation and oxidative pyrolysis of ammonia at low ***,the detailed reaction kinetics mechanism of ammonia oxidative pyrolysis stimulated by a nanosecond pulse voltage at low pressure and room temperature is *** on the reaction path analysis,the simplified mechanism is *** detailed and simplified mechanism simulation results are compared with experimental data to verify the accuracy of the simplified ***,based on the simplified mechanism,the fluid model of ammonia oxidative pyrolysis stimulated by the nanosecond pulse plasma is established to study the pre-sheath/sheath behavior and the resultant consumption and formation of key *** results show that the generation,development,and propagation of the pre-sheath have a great influence on the formation and consumption of *** consumption of NH3by the cathode pre-sheath is greater than that by the anode pre-sheath,but the opposite is true for OH and O（1S）.However,within the sheath,almost all reactions do not ***,by changing the parameters of nanosecond pulse power supply voltage,it is found that the electron number density,electron current density,and applied peak voltages are not the direct reasons for the structural changes of the sheath and ***,the discharge interval has little effect on the sheath structure and gas mixture *** research results of this paper not only help to understand the kinetic promotion of non-equilibrium excitation in the process of oxidative pyrolysis but also help to explore th

关键词： Nanosecond pulsed discharge Ammonia Oxidative pyrolysis Fluid model Global model

Electrocatalytic cleavage of a lignin β-O-4 model compound and coupling with nitrogen-containing aromatics using Prussian blue analogue-derived nickel–cobalt spinel

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Journal of Energy Chemistry 2025年第1期100卷 628-636页

作者： Yi qi Xueying chen Bowen Liu Xuliang Lin Xueqing qiu Yanlin qin Guangdong Provincial Key Laboratory of Plant Resources Biorefinery School of Chemical Engineering and Light Industry Guangdong University of Technology Guangdong Provincial Laboratory of Chemistry and Fine Chemical Engineering Jieyang Center Guangdong Basic Research Center of Excellence for Ecological Security and Green Development Guangdong University of Technology

Electrochemical conversion of lignin for the production of high-value heterocyclic aromatic compounds has great *** demonstrate the targeted synthesis and cation modulation of NiCo2O4spinel nanoboxes,synthesized via cation exchange and calcination *** catalysts exhibit excellent efficacy in the electrocatalytic conversion of lignin model compounds,specifically 2-phenoxy-1-phenylethanol,into nitrogen-containing aromatics,achieving high conversion rates and *** catalysts were synthesized via a cation exchange and calcination oxidation process,using Prussian blue nanocubes as *** porous architecture and polymetallic composition of the NiCo2O4spinel demonstrated superior performance in electrocatalytic oxidative coupling,achieving a 99.2 wt%conversion rate of the 2-phenoxy-1-phenylethanol with selectivities of 37.5 wt%for quinoline derivatives and 31.5 wt%for *** innovations include the development of a sustainable one-pot synthesis method for quinoline derivatives,the elucidation of a multistage reaction pathway involving CAO bond cleavage,hydroxyaldol condensation,and CAN bond formation,and a deeper mechanistic understanding derived from DFT *** work establishes a new strategy for lignin valorization,offering a sustainable route to produce high-value nitrogen-containing aromatics from renewable biomass under mild conditions,without the need for additional reagents.

关键词： Spinel Biomass valorization Electrocatalysis Lignin oxidation Coupling

Cloning, Expression of apxl Gene of Actinobacillus pleuropneumoniae and Development of ELISA

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Agricultural Sciences in China 2003年第5期2卷 578-582页

作者： LIU Jian-jie, he qi-gai, chen Huan-chun, WU Bin, XU Xiao-juan, LIU Jun-fa, TANG Xian-chun and BEI Wei-chengCollege of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070 , P.R. China

Based on the published nucleotide sequence of the apxICA of Actinobacillus pleuropneumoniae in Genbank(S4074), a pair of primers were designed. A 3 640 bp(4 687 - 8 326 bp)gene fragment was amplified by PCR from the isolated strain of A. pleuropneumoniae serovar 1. Then, it was cloned into pMD18-T, identified by both restriction endonuclease and sequence analysis, and inserted into pET-28a expression vector to yield the expression plasmid. SDS-PAGE result indicated expression of apxICA in BL21 (DE3), Western blot analysis showed the protein's immunogenicity. Using the expressed protein, ELISA was established to detect serum antibody against ApxI. The feature of ELISA to detect highly virulent A. pleuropneumoniae strains infection was proved by primary clinical application.

关键词： Actinobacillus pleuropneumoniae apxICA gene Cloning Prokaryotic expression ELISA

基于相干检测的Nyquist信号光纤传输技术研究

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光通信技术 2016年第9期40卷 13-15页

作者：李梦琦何晶陈林湖南大学信息科学与工程学院长沙410082

提出一种224Gb/s 16QAM Nyquist偏振复用(PDM)相干光通信系统。采用基于数据辅助的信道估计及频域均衡方法实现对系统信道损伤的补偿。研究了普通的频域均衡(FDE)及重叠的频域均衡(OFDE)对系统传输性能的影响,对采用FDE和OFDE均衡的16QA... 详细信息

提出一种224Gb/s 16QAM Nyquist偏振复用(PDM)相干光通信系统。采用基于数据辅助的信道估计及频域均衡方法实现对系统信道损伤的补偿。研究了普通的频域均衡(FDE)及重叠的频域均衡(OFDE)对系统传输性能的影响,对采用FDE和OFDE均衡的16QAM Nyquist PDM信号分别经过480km和640km标准单模光纤(SSMF)传输后的性能进行了仿真。

关键词： Nyquist 偏振复用 QAM调制数字信号处理

Expression of Porcine Interleukin-2 and Porcine Interleukin-6 and Their Adjuvant Effects on Gene Deleted Vaccine of Pseudorabies Virus(TK^-/gG^-/LacZ^+)

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Agricultural Sciences in China 2003年第8期2卷 924-929页

作者： YAN Lin, he qi-gai, chen Huan-chun, XIAO Shao-bo, WU Mei-zhou,LU Jian-qiang and HAN Li(Laboratory of Virology, College of Animal Science and Veterinary Medicine, Huazhong Agriculture University , Wuhan 430070 , P. R. China) Laboratory of Virology College of Animal Science and Veterinary Medicine Huazhong Agriculture University Wuhan 430070 P.R.China

Porcine interleukin-2 and porcine interleukin-6 cDNA sequences were cloned into the expressing vectors pET-28a and pGEX-KG respectively. They were expressed in E. coli BL21(DE3)with high-level production. The gene deleted vaccine of pseudorabies virus Ea strain(TK-/gG-/LacZ+)was mixed with the two different purified recombinant proteins each, or both, with the doses of 2, 5 or 10 μg ml-1. Ten groups of pseudorabies negative antibody swines were immuned twice with tested vaccines with different doses, or control vaccine, respectively. The antibody liters of the test groups were detected by neutralization test, and the daily weight gains of swines were calculated and analyzed statistically. In the study, all the neutralizing antibody ti-ters in test groups were higher than the control group, and the recombinant proteins appeared a dose dependent adjuvant effect. The tested vaccines with 2 μg ml-1 pIL-2 and with 10 μg ml-1 pIL-2/pIL-6 got significant and extremely significant differences, compared with the vaccines without pILs. The difference of the daily weight gain indicated the potential positive influence of pIL-2 and pIL-6 on immune protection.

关键词： Porcine interleukin-2 Porcine interleukin-6 Expression Gene deleted vaccine of pseudora-bies virus(TK-/gG-/LacZ+) Adjuvant effect