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1.
《Molecular cell》2020,77(6):1176-1192.e16
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2.
R. Kempken A Preißmann W. Berthold 《Journal of industrial microbiology & biotechnology》1995,14(1):52-57
Summary Animal cells from 80-L and 2000-L fed batch fermentations were removed by a prototype disc stack centrifuge in order to achieve a fast and reliable separation of solids from large quantities of cell culture fluids. The clarification capacity was excellent for animal cells but particles remained in the liquid phase and affected further downstream processing of the cell-free harvest fluid. No significant loss of product was observed. A number of parameters were monitored to optimize process conditions for use with animal cells. 相似文献
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放射污染区古菌分离及多样性分析 总被引:1,自引:0,他引:1
【目的】研究放射污染区古菌多样性。【方法】放射污染区采集土样,采用甘油-精氨酸培养基(GJ)、甘油-天冬氨酸培养基(C1)、海藻糖-肌酸培养基(B7)、甘露醇-丙氨酸培养基(Z5)、干酪素-甘露醇培养基(CMKA)、壳聚糖-天冬酰胺培养基(F6)、甘露醇-酸水解酪蛋白培养基(GW1)、CM培养基、HP培养基和KC培养基10种分离培养基,采用梯度稀释法对古菌进行分离,将分离获得的菌株经形态特征,16S rRNA基因片段扩增及限制性内切酶酶切,选取酶切图谱中存在差异性的条带进行测序,最终通过序列比对,聚类分析,获得不同种类的古菌资源。【结果】从该土样中共获得了256株古菌,最终筛选出71株不同类型的古菌,这71株古菌均属于广古菌门,盐杆菌纲,盐杆菌目,盐杆菌科,分布于盐陆生菌属(Haloterrigena)、纳白菌属(Natrialba)、盐球菌属(Halococcus)、盐红菌属(Halorubrum)、盐长寿菌属(Halovivax)、纳线菌属(Natrinema)、盐碱球菌属(Natronococcus)、盐二型菌属(Halobiforma)、盐惰菌属(Halopiger)、盐池栖菌属(Halostagnicola)、富盐菌属(Haloferax)11个属,26个种,其中31株菌的16S rRNA基因序列与已有效发表菌株的序列相似性小于98%,Haloterrigena为该土样的优势菌属。对于分离效果较好的F6培养基采用了梯度营养成分的稀释,最终获得了19株古菌,这些菌株相互之间存在一定的差异性。【结论】本次分离获得了大量的古菌,表明放射污染区存在着较为丰富的古菌资源,其中蕴藏着多种新的物种类型,具有较大的研究价值。 相似文献
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Mei-Jin Guo Ying-Ping Zhuang Ju Chu Si-Liang Zhang Ai-Sheng Xiong Ri-He Peng Quan-Hong Yao 《Process Biochemistry》2007,42(12):1660-1665
A genetically engineered Pichia pastoris FPHY34 strain containing a 1.3 kb thermostable phytase gene (fphy) evolved by DNA shuffling was constructed and screened. Expression and purification conditions for the recombinant phytase were developed in this study. The effect of Pi on recombinant phytase expression and cell growth of P. pastoris FPHY34 was tested in shake flask culture. Optimization of carbon sources for cell growth and methanol feeding strategies for phytase expression in P. pastoris FPHY34 was carried out in a 50-L fermenter by fed-batch fermentation. The purification of phytase was investigated by micro-filtration and ultra-filtration followed by desalting, ion-exchange chromatography, and gel filtration in the ÄKTA system. It showed that the optimum inorganic phosphorus is 13.6 g L−1 and that glucose can be used as a substrate for P. pastoris cell growth instead of glycerol; the biomass yield of glycerol (YX/S) is slightly higher than that of glucose. Different profiles of lag phase and respiratory quotient (RQ) displayed between glucose and glycerol as the sole carbon source. The maximum phytase activity in per millimetre reached 2508 U mL−1 at a methanol feed rate of 3.0 mL L−1 h−1 after 80 h period of induction. A purification factor of 41.1 with a 32% yield was achieved after chromatographic purification. The specific enzyme activity was 80 U mg−1 and 3281 U mg−1 in that supernatant fraction and after gel filtration purification, respectively. The strain P. pastoris FPHY34 showed a promising application in phytase industrial production. 相似文献
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Separation of algal mixtures and bacterial mixtures with flow-microfluorometer using chlorophyll and ethidium bromide fluorescence 总被引:4,自引:0,他引:4
A. S. Paau J. R. Cowles J. Oro A. Bartel E. Hungerford 《Archives of microbiology》1979,120(3):271-273
The applicability of flow-microfluorometer to separate microbial cells was demonstrated with algal and bacterial cells. Algal mixtures were sorted according to the natural chlorophyll fluorescence and the bacterial mixtures were sorted according to the fluorescence of ethidium bromide-stained nucleic acid.Abbreviation FMF
Flow-microfluorometer 相似文献
9.
高速逆流色谱法分离纯化茶黄素 总被引:21,自引:0,他引:21
首次应用高速逆流色谱法分离纯化茶黄素单体成分,溶剂系统为乙酸乙酯-正己烷-甲醇-水(3:1:1:6),优化了分离茶黄素的条件。同时与SephadexLH-20柱色谱法梯度洗脱对比,结果表明,高速逆流色谱法分离时间相对较短,可进行较大量的分离制备。高速逆流色谱法较之SephadexLH-20柱色谱法还有一个突出的优点,即无不可逆吸附污染及不会导致样品化学变性。 相似文献
10.
Gianni Pedrizzetti Luigino Zovatto Federico Domenichini Angela Tortoriello 《Computer methods in biomechanics and biomedical engineering》2013,16(3):219-231
Pulsatile flow inside a moderately elastic circular conduit with a smooth expansion is studied as a model to understand the influence of wall elasticity in artery flow. The solution of the simultaneous fluid-wall evolution is evaluated by a perturbative method, where the zeroth order solution is represented by the flow in a rigid vessel; the first order correction gives the wall motion and induced flow modification without the need to solve the difficult coupled problem. Such an approach essentially assumes a locally infinite celerity, therefore it represent a good approximation for the fluid-wall interaction in sites of limited extent (branches, stenosis, aneurism, etc.), which include typical situations associated with vascular diseases. The problem is solved numerically in the axisymmetric approximation; the influence of wall elasticity on the flow and on the unsteady wall shear stress is studied in correspondence of parameters taken from realistic artery flow. Attention is posed to the role of phase difference between the incoming pressure and flow pulses. 相似文献