Abstract:
:Overexpression of the cyclin-dependent kinase inhibitor p27 and exposure to low temperature (30 degrees C) represent two strategies to establish controlled proliferation processes for production of therapeutic proteins using Chinese hamster ovary (CHO) cells. Here we analyze the effect of growth inhibition on the quality of the human model glycoprotein SEAP (secreted alkaline phosphatase) for both strategies in monoclonal CHO-derived cell lines. Separation of purified SEAP samples using two-dimensional gel electrophoresis showed that production by proliferation-controlled CHO cultures did not alter the overall integrity of the product. Further, oligosaccharide profiles were compared using HPEC-PAD analysis. No differences were detectable between SEAP profiles obtained from p27 growth-arrested and proliferating cultures. However, production at 30 degrees C led to a significant increase in the degree of sialylation, an effect that is generally considered beneficial for the in vivo efficacy of protein therapeutics. In the production context presented here, SEAP expression is controlled by the tetracycline- (tet) repressible gene regulation system. Here we show low temperature-induced upregulation of the tetracycline-dependent transactivator (tTA). This induction has been shown by Northern blot analysis to occur at the mRNA level and is independent of the promoters driving the transactivator. We also describe a novel bottleneck in productivity at low temperature found in p27 growth-arrested CHO cells cultivated at 30 degrees C.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Kaufmann H,Mazur X,Marone R,Bailey JE,Fussenegger Msubject
Has Abstractpub_date
2001-03-20 00:00:00pages
592-602issue
6eissn
0006-3592issn
1097-0290pii
10.1002/1097-0290(20010320)72:6<592::AID-BIT1024>3journal_volume
72pub_type
杂志文章abstract::Modern large-scale agricultural practices that incorporate high density farming with subtherapeutic antibiotic dosing are considered a major contributor to the rise of antibiotic-resistant bacterial infections of humans with species of Salmonella being a leading agriculture-based bacterial infection. Microcin J25, a p...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26772
更新日期:2018-10-01 00:00:00
abstract::The thermophilic fungus Sporotrichum cellulophilum was immobilized with nonwoven materials for cellulase production. The cellulose powder concentration in the medium was an important factor controlling cellulase production. When the cellulose powder concentration in the nonwoven materials was more than 4%, cellulase p...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260280814
更新日期:1986-08-01 00:00:00
abstract::Connexin-43 (Cx43) containing giant liposomes (GL) were prepared by a baculovirus expression-liposome fusion method. Recombinant budded viruses expressing Cx43 were prepared and then fused with GLs containing DOPG/DOPC at pH 4.5. Connexon formation on the GL membrane was observed by transmission electron microscope. H...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22845
更新日期:2010-12-01 00:00:00
abstract::The extracellular matrix provides structural components that support the development of tissue morphology and the distribution of growth factors that modulate the overall cellular response to those growth factors. The ability to manipulate the presentation of factors in culture systems should provide an additional deg...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20611
更新日期:2005-08-05 00:00:00
abstract::A software sensor was developed to determine the volumetric biomass activity of animal cell cultivations on-line. It was based on the on-line estimation of the ATP-production rate from the oxygen uptake and the lactic-acid production rate. The sensor was verified for a batch culture of Vero cells, and a batch and a co...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19960720)51:2<206::AID-BIT
更新日期:1996-07-20 00:00:00
abstract::A mixed culture of sulfate-reducing bacteria containing the species Desulfovibrio desulfuricans was used to study sulfate-reduction stoichiometry and kinetics using ethanol as the carbon source. Growth yield was lower, and kinetics were slower, for ethanol compared to lactate. Ethanol was converted into acetate and no...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:
更新日期:2000-12-05 00:00:00
abstract::In metabolic engineering, systems which allow coordinated control of two metabolic pathways can be useful. We designed two expression systems and demonstrated their application by coordinating glycogen synthesis and degradation. The first expression vector pMSW2 expressed the glycogen synthesis genes in one operon and...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19970720)55:2<419::AID-BIT
更新日期:1997-07-20 00:00:00
abstract::To monitor gas reaction rates in animal cell culture at constant dissolved oxygen concentration (DO) and constant pH it was necessary to develop improved control methods. Decoupling of both controllrs was obtained by manipulation of molar fractions of oxygen and carbon dioxide in the gas phase. Two pairs of DO and pH ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260450107
更新日期:1995-01-05 00:00:00
abstract::Pyruvate production by Torulopsis glabrata was used as a model to study the mechanism of product inhibition and the strategy for enhancing pyruvate production. It was found that the concentration of cell growth and pyruvate deceased with the increase of NaCl and sorbitol concentrations. To enhance the osmotic stress r...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21290
更新日期:2007-07-01 00:00:00
abstract::Short-chain carboxylic acids generated by various mixed- or pure-culture fermentation processes have been considered valuable precursors for production of bioalcohols. While conversion of carboxylic acids into alcohols is routinely performed with catalytic hydrogenation or with strong chemical reducing agents, here, a...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24786
更新日期:2013-04-01 00:00:00
abstract::Oxygen and nutrient limitation was investigated in order to identify the origin of a lower specific ajmalicine production in Catharanthus roseus cultures at high cell densities in an induction medium. The effect of oxygen limitation was explored by comparing two identically aerated and agitated high cell density biore...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260440409
更新日期:1994-08-05 00:00:00
abstract::The use of microalgae for biofuel production will be beneficial to society if we can produce biofuels at large scales with minimal mechanical energy input in the production process. Understanding micro-algal physiological responses under variable environmental conditions in bioreactors is essential for the optimizatio...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24619
更新日期:2013-01-01 00:00:00
abstract::The purpose of this study was to understand bacteria profile modification and its applications in subsurface biological operations such as biobarrier formation, in situ bioremediation, and microbial-enhanced oil recovery. Biomass accumulation and evolution in porous media were investigated both experimentally and theo...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(sici)1097-0290(20000705)69:1<47::aid-bit6
更新日期:2000-07-05 00:00:00
abstract::Batch fermentations of glucose to ethanol by Z. Mobilis.(ATCC 10988) were examined in several semidefined nutrient media. The measurement of acid produced by the microorganism was used to study its transient fermentation characteristics. Limitation of nitrogen source in the semidefined medium of Rogers and coworkers(2...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260310803
更新日期:1988-05-20 00:00:00
abstract::Morphology has a crucial effect on productivity and the supply of substrate for cultures of filamentous fungi. However, cultivation parameters leading to the desired morphology are often chosen empirically as the mechanisms governing the processes involved are usually unknown. For coagulating microorganisms like Asper...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20130
更新日期:2004-07-20 00:00:00
abstract::Gene transcription is regulated by transcription factors that can bind to specific regions on DNA. Antigene oligonucleotides (oligos) can bind to specific regions on DNA and form a triplex with the double-stranded DNA. The triplex can competitively inhibit the binding of transcription factors and, as a result, transcr...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/1097-0290(20001120)70:4<467::aid-bit13>3.0
更新日期:2000-11-20 00:00:00
abstract::The use of cell numbers rather than mass to quantify the size of the biotic phase in animal cell cultures causes several problems. First, the cell size varies with growth conditions, thus yields expressed in terms of cell numbers cannot be used in the normal mass balance sense. Second, experience from microbial system...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19971120)56:4<372::AID-BIT
更新日期:1997-11-20 00:00:00
abstract::A continuous viral inactivation (CVI) chamber has been designed to operate with acceptable residence time distribution (RTD) characteristics. However, altering the CVI's geometry and operation to accommodate the scale was not obvious. In this work, we elucidate the influence of Dean vortices and leverage the transitio...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.27223
更新日期:2020-03-01 00:00:00
abstract::The efficiency of a versatile in vivo cascade involving a promiscuous alcohol dehydrogenase, obtained from a biodiversity search, and a Baeyer-Villiger monooxygenase was enhanced by the independent control of the production level of each enzyme to produce ε-caprolactone and 3,4-dihydrocoumarin. This goal was achieved ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.27133
更新日期:2019-11-01 00:00:00
abstract::An integrated approach is used to develop a rapid sampling strategy for the quantitative analysis of in vivo kinetic behavior based on measured concentrations of intracellular metabolites in Saccharomyces cerevisiae. Emphasis is laid on small sample sizes during sampling and analysis. Subsecond residence times are acc...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10048
更新日期:2001-11-20 00:00:00
abstract::The solution structure of plasmid DNA is known to be a strong function of solution conditions due to intramolecular electrostatic interactions between the charged phosphate groups along the DNA backbone. The objective of this work was to determine whether it was possible to enhance the use of ultrafiltration for separ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25836
更新日期:2016-04-01 00:00:00
abstract::Flow cytometry is a fast and sensitive method that allows monitoring of different cellular parameters on large samples of a population. Protein distributions give relevant information on growth dynamics, since they are related to the age distribution and depend on the law of growth of the population and the law of pro...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260250510
更新日期:1983-05-01 00:00:00
abstract::This article describes a methodology that implements a Markov decision process (MDP) optimization technique in a real time fed-batch experiment. Biological systems can be better modeled under the stochastic framework and MDP is shown to be a suitable technique for their optimization. A nonlinear input/output model is ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19970720)55:2<317::AID-BIT
更新日期:1997-07-20 00:00:00
abstract::This research investigates the effect of solids retention time (SRT) on the acid-phase anaerobic digestion of primary sludge. A series of experiments were conducted using two continuous-flow 3-L units with the following configuration: a completely mixed reactor (CMR) with clarifier and solids recycle and an upflow ana...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260440103
更新日期:1994-06-05 00:00:00
abstract::Molecular chaperones in aqueous-organic mixtures can broaden the utility of biocatalysis by stabilizing enzymes in denaturing conditions. We have designed a self-renaturing enzyme-chaperone chimera consisting of penicillin amidase and a thermophilic chaperonin that functions in aqueous-organic mixtures. The flexible l...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22254
更新日期:2009-04-01 00:00:00
abstract::In analyzing microbial cellulose utilization, it would be useful to independently measure the mass concentration of cells and cellulase enzymes. Such measurements would allow investigation of the allocation of cellular resources between synthesis of cells and cellulase, in vivo cell- and cellulase-specific cellulose h...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10142
更新日期:2002-02-15 00:00:00
abstract::Nanoparticles (NPs) are able to deliver a variety of substances into eukaryotic cells. However, their usage is often hampered by a lack of specificity, leading to the undesired uptake of NPs by virtually all cell types. In contrast to this, yeast is known to be specifically taken up into immune cells after entering th...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.27226
更新日期:2020-03-01 00:00:00
abstract::Pretreatment of rice straw by using renewable cholinium amino acids ionic liquids ([Ch][AA] ILs)-water mixtures and the subsequent enzymatic hydrolysis of the residues were conducted in the present work. Of the eight mixtures composed of ILs and water, most were found to be effective for rice straw pretreatment. After...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24862
更新日期:2013-07-01 00:00:00
abstract::Exposure of Bacillus subtilis to a shear rate of 1,482/s leads to a rapid loss of cell viability after 10 h of growth. Biochemical and molecular evidences provided below strongly suggest that cell death under high shear results from an apoptosis-like process similar to that described in eukaryotes, with activation of ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20835
更新日期:2006-05-05 00:00:00
abstract::The conditions for the introduction of active carbonate groups into supports containing hydroxyl groups by reaction with 5-norbornene-2.3-dicarboximido carbonochloridate are described. Up to 1.5 mmol carbonate groups/g dry Sepharose 4B could be bound. In the case of glycine the reaction of the activated supports with ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260330105
更新日期:1989-01-05 00:00:00