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171.
Wei Wen Su 《Biotechnology Techniques》1995,9(4):259-264
Summary The effect of agitation and aeration on filtration of Anchusa officinalis culture in a stirred tank bioreactor integrated with an internal filter unit was investigated. Increases in suction head of the pump that drove the filtration process were measured at impeller speeds of 100 and 200 rpm. Surprisingly, suction head attained at 200 rpm was about 40% higher than at 100 rpm. Direct observation of the cake deposition process in the reactor using a dilute cell suspension revealed that the filter cake formed at 100 rpm was thicker, but less compact. Aeration at 0.4 vvm was shown to have little effect on the filtration rate, since the bulk fluid flow was dominated by the impeller hydrodynamics. The initial flux can be recovered by filter backwashing with compressed air at a flow rate of 0.6 vvm for a duration of 5 minutes. 相似文献
172.
Summary Three screening methods were used to isolate GL-7-ACA acylase-producing strains. Three positive isolates were identified with Pseudomonas nitroreducens CCRC 11041 possessing the highest activity, against GL-7-ACA and GL-7-ADCA. No activity was detected when Ceph C or succinyl-7-ACA was used as substrate; glutaric acid was found to be inhibitory. CCRC 11041 could produce maximal GL-7-ACA acylase activity when cultivated on meat extract medium II. The enzyme had a pH optimum of 5.0 and a temperature optimum of 42°C. 相似文献
173.
Summary A simple and convenient technique was developed based on the principle of Warburg manometric method to measure O2 uptake rate (OUR) and CO2 evolution rate (CER) of suspended cells in a shake flask culture. It was successfully applied to suspension cultures of rice (Oryza sativa) and Panax notoginseng cells, and some important bioprocess parameters, such as OUR, CER, respiratory quotient (RQ), specific OUR (SOUR) and specific CER (SCER), were quantitatively obtained. The measuring system is easy to operate, able to treat many samples simultaneously and is economical. 相似文献
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无性系植物种群生态学研究进展及有关概念 总被引:74,自引:5,他引:69
无性系植物种群生态学研究进展及有关概念刘庆钟章成(中国科学院成都生物研究所,610041)(西南师范大学生物系,重庆630715)AdvancesinEcologicalResearchofClonalPlantPopulationandSomeRe... 相似文献
178.
Labeling of sialoglycoproteins with carbon-14 in vitro was performed by reacting the aldehyde groups, generated by mild periodate oxidation of the terminal sialyl groups, with 14C-labeled sodium cyanide to produce the labeled cyanohydrin derivatives (Kiliani reaction). Labeling with tritium was carried out by reduction of the aldehyde groups generated on the sialyl residues with 3H-labeled sodium borohydride following standard procedures. The behavior of both types of labeled specimens of fetuin and ovine submaxillary mucin, individually and in mixtures, was investigated by gel-filtration chromatography, gel electrophoresis, and cesium bromide gradient ultracentrifugation. The labeled sialyl residues were subjected to partial characterization: color yield with the resorcinol and thiobarbituric acid reagents, behavior on ion-exchange chromatography, and susceptibility to mild acid and enzymatic hydrolyses. In addition to these model glycoproteins, this procedure was also utilized to label the sialoglycoproteins present in human tracheobronchial secretions collected from normal subjects and patients with chronic bronchitis. The potential uses of this approach for comparative studies of normal and pathological sialoglycoconjugates available in minute amounts is described. The extension of this approach to the labeling of the galactosyl and N-acetylgalactosaminyl moieties of glycoconjugates following treatment with galactose oxidase is outlined. 相似文献
179.
Y Wen K S Famulski E Carafoli 《Biochemical and biophysical research communications》1984,122(1):237-243
The Ca2+-dependent K+ permeability of heart sarcolemma vesicles was measured by following the transmembrane movement of the charge compensating tetraphenylborate anion. The increase in vesicles permeability induced by Ca2+ is lost when membrane proteins are dephosphorylated by an endogenous protein phosphatase and is restored by a phosphorylation process catalysed by a cAMP-dependent protein kinase. The calmodulin antagonist R 24571 lowers the Ca2+-dependent K+ permeability by decreasing the Ca2+ affinity of the K+ transporting system. 相似文献
180.