Studies on The Conditions of β-glucanase Production by Recombinant Escherichia coli

本文对利用胞外分泌型重组大肠杆菌（Escherichiacoli）JM109-pLF3发酵生产β-1,3-1,4-葡聚糖酶的培养基及发酵工艺优化进行了系统的研究。首先对菌种产酶培养基中的碳、氮源进行了优化，结果表明甘油为最佳碳源，酵母粉和硝酸钠为最佳混合氮源，且氮源对产酶影响更大。采用Plackett-Burman设计法筛选出了培养基中影响产酶的重要因素为酵母粉，确定出最佳培养基组成为：酵母粉12g·L-1、甘油6g·L-1、NaCl10g·L-1、NaNO37.21g·L-1、KH2PO42.4g·L-1、K2HPO412.5g·L-1。对摇瓶中培养条件的优化采用单因子实验法，研究了温度、培...In the essay the recombinant Escherichia coli JM109-pLF3，which can secrete heterologous enzyme into the culture medium，was employed to produce β-1,3-1,4- glucanase. The composition of enzyme production medium was optimized, and the fermentation strategy was systematically studied to improve the β-1,3-1,4-glucanase production. Glycerol, yeast extract and NaNO3 that were found influencing enzyme pro...学位：工学硕士院系专业：化学化工学院化学工程与生物工程系_工业催化学号：20033301

Production of β-glucanase by Biosynthesis Method

概述了微生物来源的β-葡聚糖酶国内外生产现状,介绍了生产β-葡聚糖酶的不同方法,对生物合成法及其产酶的影响因素进行了具体分析,并指出今后中国β-葡聚糖酶的研究方向。Present research situation and strategies of production of β-glucanase from micro-organism were reviewed.Factors influencing β-glucanase production by biosynthesis method were analysed specifically,and what should be researched in β-glucanase in our country was pointed out.广东省科技计划项目资

Production of β-glucanase by cultivation of immobilized recombinant E.coli cells in a packed bed reactor

以多孔陶瓷为载体吸附法固定重组大肠杆菌E.coli JM 109-pLF3表达胞外β-葡聚糖酶。考察了固定床间歇培养时循环流速和曝气量对发酵液酶活力的影响。当循环流速达到44.19mL/min,曝气量达到0.6mL/min时,培养48h后,发酵液的酶活力达100.3U/mL。固定化细胞具有良好的重复使用能力,在连续5批次实验中,培养48h后的酶活力均在100U/mL左右。固定床连续培养时,固定化细胞能够保持恒定的产酶效率,当稀释率为0.05h-1时,发酵液中得到的酶活力为39.1U/mL。β-glucanase produced by immobilized Escherichia coli JM 109-pLF3 in a packed bed bioreactor was studied.In batch fermentation,the highest enzyme activity of 100.3 U/mL was achieved at a recycling rate of 44.49 mL/min and an aeration rate of 0.6 mL/min after 48 h cultivation.In repeated batch operation,the enzyme activity up to 100 U/mL was obtained in 5 cycless,howing high stability of the immobilized cells.In continuous fermentation,the production of β-glucanase by immobilized cells was kept more or less constant.When the dilution rate was 0.05 h-1,the enzyme activity in the fermentation broth was 39.1 U/mL.厦门市科技计划项目(No.3502Z20055017

Studies on the Conditions of β-glucanase Production by Recombinant Escherichia coli

通过对重组大肠杆菌JM109-Plf3摇瓶发酵生产β-1,3-1,4-葡聚糖酶工艺条件的研究,得出最佳培养条件为:温度39℃,摇床转速150 r/MIn,培养基装量20 Ml/250 Ml,培养基初始PH 6.7,种子培养时间16 H,接种量1%.在最佳培养条件下,发酵30 H酶活力达到最大值481.41 u/Ml.最优条件下摇瓶恒速补加氮源对酶活的提高贡献较大,且适当提高流加量对促进产酶效果更明显,酶活力可达628.30 u/Ml,为初始时的2.1倍.The fermentation conditions of recombinant Escherichia coli JM109 harboring pLF3 for extracellular β-glucanase production were investigated.The optimized culture conditions were determined as follows:temperature 39℃.shaking speed 150 r/min.culture volume 20 mL in 250 mL shake flask,initial pH 7.0,inoculating age 16 h,and inoculating quantity 1.0%.Under these conditions,a maximum β-glucanase activity of 481.41 U/mL was obtained after 30 h fermentation.Fed-batch strategies were also studied in shaking flask.Higher β-glucanase activity of 628.30 U/mL,which was almost 2.1 times higher than that obtained at the initial conditions,was achieved by feeding high concentration nitrogen sources at constant rate.厦门市科技计划项目(3502Z20055017);厦门大学新世纪优秀人才支持计划资

Optimization of recombinant Escherichia coli fermentation medium affecting β1-3,1-4-glucanase production

通过对重组E.coliJM109发酵生产β1-3,1-4-葡聚糖酶条件的研究,发现培养基中氮源含量是影响β-葡聚糖酶产量的主要因素。优化后的培养基组成为:酵母粉12 g/L,甘油6 g/L、NaCl 10 g/L,NaNO37.21g/L,KH2PO42.4 g/L,K2HPO412.5 g/L。优化条件下,发酵30h,β-葡聚糖酶活力达到297.71 U/mL,约为初始时的14.3倍。The fermentation conditions of recombinant Escherichia coli for cell growth and β1-3,1-4-glucanase production were investigated.The optimized medium was obtained: yeast extract 12g/L,glycerol 6g/L,NaCl 10g/L,NaNO_3 7.21g/L,KH_2PO_4 2.4g/L,K_2HPO_4 12.5g/L.The maximum of 297.71U/mL β-glucanase activity was obtained almost 14.3 times higher than that of the initial conditions.厦门市科技计划项目资助(NO:3502Z20055017

使用數位科技輔助Z世代年輕人教學與學習

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种植于人工梭梭(Haloxylon ammodendron)林的肉苁蓉(Cistanche deserticola)个体质量特征/Characteristics of Individual Mass of Cistanche Deserticola Inoculated in Artificial Haloxylon ammodendron Forest in the Hinterland of Taklimakan Desert[J]

为掌握人工种植条件下肉苁蓉(Cistanche deserticola)个体质量特征,在塔克拉玛干沙漠腹地咸水滴灌人工梭梭林内,采用统一的开沟、撒种接种方式,对不同林龄、不同深度接种肉苁蓉以及造林当年接种连年采收肉苁蓉的质量进行了调查和分析.结果表明:(1)所有样地出土肉苁蓉个体间质量差异大,分布离散程度高.(2)接种时林龄越大,出土肉苁蓉个体平均质量、质量品质较好的比率以及质量分布离散程度都越高;不同林龄间肉苁蓉个体质量有极显著差异.造林当年接种、连年出土肉苁蓉个体质量的特征与不同林龄的相似,但质量品质较好的比率相对较低.(3)在40～120 cm深度,随种植深度增加,出土2年生以上肉苁蓉个体的数量以及质量品质较好的比率总体呈现增加趋势,并可以分为3个层面:40 cm、50～80 cm、100～120 cm.其中40 cm深度质量指标明显较低,其他深度间没有表现出明显的差异和规律,100～120 cm深度的肉苁蓉个体相对细长、品相差

塔克拉玛干沙漠腹地咸水滴灌人工种植肉苁蓉技术的试验研究[C]

在塔克拉玛干沙漠腹地，利用咸水滴灌技术，从肉苁蓉种植的开挖方式、接种深度，播种方式以及稳产技术等方面进行了试验研究。结果表明：①提高肉苁蓉种子和寄主根系接触的几率是提高人工接种肉苁蓉接种率的有效途径。不同种植方式的接种效果(率)表现为：沟种＞打洞＞穴种，撒种＞种植带(种植纸)。②沟种、撒种适宜的播种量为300-500粒/m，接种深度应控制在寄主主要根系分布层以内，同时要结合作业方式及作业成本来综合确定，一般不超过70 cm。③采取“平茬”方式采挖肉苁蓉，肉苁蓉具有重新萌发的现象，但实际生产技术需要进一步完善。④人工接种肉苁蓉具有一次接种，多年采收的效果，但肉苁蓉出土率年际间差异较大。采用沟种、撒种技术，春季接种，接种后连续三年平均出土率可以保持在1株/m以上，肉苁蓉鲜重产量达1800kg/hm2，经济效益显著