Abstract:
:The use of a temperature switch to control the growth and productivity of temperature-sensitive (ts) mutants was investigated to extend the productive life span of recombinant Chinese hamster ovary (CHO) cells in batch culture. Bromodeoxyuridine was used at 39 degrees C to select mutagenized CHO-K1 cells, which resulted in the isolation of 31 temperature-sensitive mutants that were growth inhibited at 39 degrees C. Two of these mutants were successfully transfected with the gene for tissue inhibitor of metalloproteinases (TIMP) using glutamine synthetase amplification, and a permanent recombinant cell line established (5G1-B1) that maintains the ts phenotype.Continuous exposure to the nonpermissive temperature (npt) of 39 degrees C led to a rapid decline in cell viability. However, a temperature regime using alternating incubations at 34 degrees C and 39 degrees C arrested the 5G1-B1 cells while retaining a high cell viability for up to 170 h in culture. The specific production rate of the growth-arrested cells was 3-4 times that of control cultures maintained at a constant 34 degrees C over the crucial 72-130-h period of culture, which resulted in a 35% increase in the maximum product yield. Glucose uptake and lactate production both decreased in arrested cells. Flow cytometric analysis indicated that 5G1-B1 cells arrested in the G(1) or G(0) phase of the cell cycle, and no major structural damage was caused to these cells by the alternating temperature regime.These results demonstrate that growth-arrested ts CHO cells have increased productivity compared to growing cultures and maintain viability for longer periods. The system offers the prospect of enhancing the productivity of recombinant mammalian cells grown in simple batch fermentors.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Jenkins N,Hovey Adoi
10.1002/bit.260420903subject
Has Abstractpub_date
1993-11-05 00:00:00pages
1029-36issue
9eissn
0006-3592issn
1097-0290journal_volume
42pub_type
杂志文章abstract::The mixed-culture anaerobic conversion of lactose to organic acids in a bench-scale continuous-flow stirredtank fermentor is considered. The major acidogenic end-product distribution with respect to the dilution rate are presented. A Monod chemostat model is employed to describe a microbial growth, and the influence o...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260330516
更新日期:1989-01-25 00:00:00
abstract::After injury to the central nervous system, a glial scar develops that physically and biochemically inhibits axon growth. In the scar, activated astrocytes secrete inhibitory extracellular matrix, of which chondroitin sulfate proteoglycans (CSPGs) are considered the major inhibitory component. An inhibitory interface ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24750
更新日期:2013-03-01 00:00:00
abstract::The optimal of the specific growth rate was obtained with simple mathematical model in a yeast fed-batch cultures. The model was based on the mass balance around the fed-batch system and the relationship between the specific growth rate, mu, and the specific production rate of glutathione, rho(G). The optimal profile ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260380212
更新日期:1991-06-20 00:00:00
abstract::Exchange of enzyme-bound H(2)O with T(2)O in aqueous solution followed by freeze drying provided tritiated water bound to chymotrypsin, subtilisin Carlsberg, and horseradish peroxidase. The desorption of T(2)O from these enzymes suspended in various organic solvents showed that all three enzymes lost enzyme-bound wate...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260390405
更新日期:1992-02-20 00:00:00
abstract::Membrane chromatography (MC) systems are finding increasing use in downstream processing trains for therapeutic proteins due to the unique mass-transfer characteristics they provide. As a result, there is increased need for model-based methods to scale-up MC units using data collected on a scaled-down unit. Here, a st...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25217
更新日期:2014-08-01 00:00:00
abstract::Recombinant retroviruses are effective vectors able to integrate transgenes into the target cell's genome to achieve longer-term expression. This study investigates the effect of cell lysis products, a common cell culture by-product, on the transduction of suspension cells by gammaretroviral vectors. Cell lysates deri...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22634
更新日期:2010-04-15 00:00:00
abstract::Although one of the major factors limiting the application of Bacillus subtilis as an expression host has been its production of at least eight extracellular proteases, researchers have also noticed that some proteases benefited the secretion of foreign proteins at times. Therefore, to maximize the yield of a foreign ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26992
更新日期:2019-08-01 00:00:00
abstract::An innovative type of biofilm model is derived by combining an individual description of microbial particles with a continuum representation of the biofilm matrix. This hybrid model retains the advantages of each approach, while providing a more realistic description of the temporal development of biofilm structure in...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20917
更新日期:2006-08-05 00:00:00
abstract::The continuous separation of proteins was performed in a countercurrent gradient chromatography (CGC) system. A magnetically stabilized fluidized bed (MSFB) was used to establish true countercurrent contact of a solid resin with a liquid buffer. STable pH gradients were formed in the system in less than 10 min and rem...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260480508
更新日期:1995-12-05 00:00:00
abstract::With a view toward reduction of graft loss, we explored pancreatic islet transplantation within fibrin matrices rendered pro-angiogenic by incorporation of minimal doses of vascular endothelial growth factor-A165 and platelet-derived growth factor-BB presented complexed to a fibrin-bound integrin-binding fibronectin d...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25589
更新日期:2015-09-01 00:00:00
abstract::Escherichia coli cells with formate hydrogenlyase activity that were immobilized in agar beads produced hydrogen from glucose at the approximate yield of 0.6 mole of hydrogen per mole. Succinate or thiosulphate added to glucose increased hydrogen production two-fold. Thiosulphate did not increase the rate of hydrogen ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10091
更新日期:2001-11-20 00:00:00
abstract::L-Threonine, a kind of essential amino acid, has numerous applications in food, pharmaceutical, and aquaculture industries. Fermentative l-threonine production from glucose has been achieved in Escherichia coli. However, there are still several limiting factors hindering further improvement of l-threonine productivity...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26844
更新日期:2019-01-01 00:00:00
abstract::The microscopic morphology of Trichoderma reesei QM 9414, growing in submerged culture, was studied by image analysis. The morphology was characterized by the total hyphal length, the total number of tips, the number of actively growing tips, and the length of the main hypha. To describe the growth of a single myceliu...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260470513
更新日期:1995-09-05 00:00:00
abstract::The stability of KR12H-1 transfectoma in regard to chimeric antibody production was examined during long-term, repeated batch culture without selection pressure using antibiotics. Both serum-supplemented and serum-free media were used. Regardless of the medium used, the specific antibody productivity (q(Ab)) of transf...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19960820)51:4<479::AID-BIT
更新日期:1996-08-20 00:00:00
abstract::Knowledge of the aqueous phase methane concentration is critical to understanding and controlling process kinetics in methanotrophic bioreactors. Unfortunately since no dissolved methane probe is commercially available, this data must be obtained off-line by the time-consuming gas-liquid partition method. In this stud...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21050
更新日期:2006-12-05 00:00:00
abstract::A laboratory-scale multiphase hollow fiber membrane reactor was employed to investigate the lipase-catalyzed enzymatic resolution of racemic glycidyl butyrate. A mathematical formulation was developed to simulate the performance of this system. Model parameters were determined independently (except the effective rate ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260411009
更新日期:1993-04-25 00:00:00
abstract::We have used a novel approach in conjunction with flow cytometry to quantify the biological heterogeneity of populations of the ciliate Tetrahymena pyriformis. It was found that the rate of particle uptake of exponentially growing cells is not uniform among cells and partially correlated with cell size. The physiologi...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260430505
更新日期:1994-03-05 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::More than 80 years after its discovery, penicillin is still a widely used and commercially highly important antibiotic. Here, we analyse the metabolic network of penicillin synthesis in Penicillium chrysogenum based on the concept of elementary flux modes. In particular, we consider the synthesis of the invariant mole...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25694
更新日期:2016-01-01 00:00:00
abstract::An aeration tank/sedimentation tank system is considered for large variations of organic loading. In this case, it is important to take into account the variability of the characteristics describing the oxidation of activated sludge as well as its sedimentation. The minimum cost of the treatment system is also evaluat...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260241105
更新日期:1982-11-01 00:00:00
abstract::The effects of growing Clostridium acetobutylicum NCIB 8052 in a chemostat under conditions of glucose, NH(4) (+), PO(4) (3-), Mg(2+), and Fe(2+) limitation were examined. It was noted that limitation of any major nutrient resulted in the same fermentation pattern. Conditions where minor nutrient levels were reduced a...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260290315
更新日期:1987-02-01 00:00:00
abstract::Reduction and oxidation of steroids in the human gut are catalyzed by hydroxysteroid dehydrogenases of microorganisms. For the production of 12-ketochenodeoxycholic acid (12-Keto-CDCA) from cholic acid the biocatalytic application of the 12α-hydroxysteroid dehydrogenase of Clostridium group P, strain C 48-50 (HSDH) is...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.23047
更新日期:2011-06-01 00:00:00
abstract::A novel process has been developed which uses reversed micelles to isolate denatured protein molecules from each other and allows them to refold individually. These reversed micelles are aqueous phase droplets stabilized by the surfactant AOT and suspended in isooctane. By adjusting conditions such that only one prote...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260351002
更新日期:1990-04-25 00:00:00
abstract::Many enzymes or fluorescent proteins produced in Escherichia coli are enzymatically active or fluorescent respectively when deposited as inclusion bodies. The occurrence of insoluble but functional protein species with native-like secondary structure indicates that solubility and conformational quality of recombinant ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21996
更新日期:2008-12-15 00:00:00
abstract::A desirable feature of many therapeutic glycoprotein production processes is to maximize the final sialic acid content. In this study, the effect of applying a novel chemical analog of the sialic acid precursor N-acetylmannosamine (ManNAc) on the sialic acid content of cellular proteins and a model recombinant glycopr...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26291
更新日期:2017-08-01 00:00:00
abstract::The selectivity of protein extraction by reversed micellar solutions can be improved by the addition of affinity cosurfactants bearing ligands which bind strongly to the target protein. The interactions between cosurfactant and protein, as well as the interfacial activity of both the free cosurfactant and the protein-...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260421011
更新日期:1993-11-20 00:00:00
abstract::A spinning cylindrical filter is often used to retain mammalian cells in a continuous perfusion bioreactor. This device, known as a spinfilter, has typically been with pore size smaller than the cell particles (single cells or aggregates) in order to achieve cell separation. For single cells in suspension, such an ope...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260400809
更新日期:1992-10-20 00:00:00
abstract::The effects of low intensity pulsed ultrasound (LIPUS) on proliferation and chondrogenic differentiation of human mesenchymal stem cells (hMSCs) seeded on 3D printed poly-(ethylene glycol)-diacrylate (PEG-DA) scaffolds with varying pore geometries (square and hexagonal channels) were investigated. The scaffold with sq...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26480
更新日期:2018-02-01 00:00:00
abstract::A phenomenological model of biocide action against microbial biofilms was derived. Processes incorporated in the model include bulk flow in and out of a well-mixed reactor, transport of dissolved species into the biofilm, substrate consumption by bacterial metabolism, bacterial growth, advection of cell mass within th...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19960220)49:4<445::AID-BIT
更新日期:1996-02-20 00:00:00
abstract::In glutamic acid fermentation, the molasses feeding policy and time of penicillin addition significantly affected glutamic acid production, and a fuzzy supervisory control system was developed for their quasi-optimal regulation.From the trend of the experimental data, production rules and membership functions of fuzzy...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260440113
更新日期:1994-06-05 00:00:00