Abstract:
:Actively growing Escherichia coli C600(pBR322), immobilized within the macroporous matrix of asymmetric-wall hollow-fiber membranes, has been propagated to extremely high densities, typically more than 10(12) cells/mL of accessible void volume, in some regions cells accounting for nearly 100% of the available macrovoid volume forming a tissue-like mass. Production rates of beta-lactamase, an enzyme used as an indicator of the culture's biosynthetic potential, remained at high and relatively stable levels for more than three weeks of continuous operation, and effluent supernatant enzyme activities attained 25% of the accumulated level measured in a 24-h shaker-flask culture. Based on the accessible void volume within the fiber wall, the beta-lactamase productivity was independent of the specific asymmetric membrane used. On a per cell basis, however, cells cultured using hollow-fiber membranes were only 10% as productive as those in the shaker-flask culture, possibly due to the high packing density or culture aging. By contrast, the hollow-fiber bioreactor was 100 times more productive than the shaker-flask culture on a reactor-volume basis, primarily as a consequence of the high cell densities. Reactor productivity was dependent on the number of cells in the reactor, suggesting that reactor performance was kinetically controlled and not mass transport limited.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Inloes DS,Smith WJ,Taylor DP,Cohen SN,Michaels AS,Robertson CRdoi
10.1002/bit.260251113subject
Has Abstractpub_date
1983-11-01 00:00:00pages
2653-81issue
11eissn
0006-3592issn
1097-0290journal_volume
25pub_type
杂志文章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::In view of the biochemical reaction catalyzed by enzyme powder suspended in a water-insoluble organic solvent, an equation was derived to estimate the amount of water bound to the enzyme powder. With this equation, an apparent adsorption isotherm between free water (water freely dissolved in benzene) and bound water (...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260340613
更新日期:1989-09-01 00:00:00
abstract::Integrated process concepts for enzymatic cephalexin synthesis were investigated by our group, and this article focuses on the integration of reactions and product removal during the reactions. The last step in cephalexin production is the enzymatic kinetic coupling of activated phenylglycine (phenylglycine amide or p...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10348
更新日期:2002-10-20 00:00:00
abstract::Coastal bermudagrass was pretreated by a low-temperature ammonia fiber explosion (AFEX) process, which soaked the grass in liquid ammonia and then explosively released the pressure. Saccharifying enzymes were systematically applied to the AFEX-treated grass corresponding to low, medium, and high loadings of cellulase/...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260440914
更新日期:1994-11-05 00:00:00
abstract::Shikimic acid is one of several industrially interesting chiral starting materials formed in the aromatic amino acid pathway of plants and microorganisms. In this study, the physiology of a shikimic acid producing strain of Escherichia coli (derived from W3110) deleted in aroL (shikimic acid kinase II gene), was compa...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20546
更新日期:2005-12-05 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::Light-responsive bioconjugates are synthesized by a two-step protocol calling first for cotelomerization (chain-transfer polymerization) of N-isopropylacrylamide and N-acryloxysuccinimide. The desired bioligand (biotin) is used in modified form as chain-transfer agent in this step. As a consequence, 100% of the produc...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20479
更新日期:2005-09-05 00:00:00
abstract::A priori knowledge of the dissolved oxygen (O2) concentration profile within a hepatic hollow fiber (HF) bioreactor is important in developing an effective bioartificial liver assist device (BLAD). O2 provision is limiting within HF bioreactors and we hypothesize that supplementing a hepatic HF bioreactor's circulatin...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20673
更新日期:2006-02-05 00:00:00
abstract::A mechanistic model-based soft sensor is developed and validated for 550L filamentous fungus fermentations operated at Novozymes A/S. The soft sensor is comprised of a parameter estimation block based on a stoichiometric balance, coupled to a dynamic process model. The on-line parameter estimation block models the cha...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26187
更新日期:2017-03-01 00:00:00
abstract::Conditions for the laboratory-scale production of acetoin plus diacetyl by Enterobacter cloacae ATCC 27613 were studied. Thirty-five g acetoin plus diacetyl/50 g sucrose were obtained when fermentation was carried out in 2.5 liter medium containing 12.5 g peptone and 12.5 g yeast extract, at pH 7.0, in a 5 liter conic...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260201206
更新日期:1978-12-01 00:00:00
abstract::Osteochondral tissue engineering aims to regenerate functional tissue-mimicking physiological properties of injured cartilage and its subchondral bone. Given the distinct structural and biochemical difference between bone and cartilage, bilayered scaffolds, and bioreactors are commonly employed. We present an osteocho...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.27127
更新日期:2019-11-01 00:00:00
abstract::Steam explosion after sulphur dioxide impregnation of wood chips is an effective method for improving the enzymatic digestibility of cellulose in the softwood Pinus radiata. Digestibility of pretreated fiber was progressively increased by altering the conditions of steam explosion. With increasing digestibility, there...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260310509
更新日期:1988-04-05 00:00:00
abstract::This study describes the development of a transient expression system for CHO cells based on autonomous replication and retention of transfected plasmid DNA. A transient expression system that allows extrachromosomal amplification of plasmids permits more plasmid copies to persist in the transfected cell throughout th...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20534
更新日期:2005-09-20 00:00:00
abstract::This study examines protein adsorption behavior and the effects of mobile phase modifiers in multimodal chromatographic systems. Chromatography results with a diverse protein library indicate that multimodal and ion exchange resins have markedly different protein binding behavior and selectivity. NMR results corrobora...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.23318
更新日期:2012-01-01 00:00:00
abstract::While feeding protocols and ectopic expression of anti-apoptotic genes have been used to improve the viability of hybridoma cell lines, the effect of the expression levels of survival genes on the behavior of hybridomas following nutrient supplementation is unknown. In this study, we compared the behavior of the Sp2/0...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10467
更新日期:2003-02-05 00:00:00
abstract::Steady-state simulations using our previously developed structured kinetic model of antibody synthesis and secretion by hybridoma cells are used here in conjunction with factorial design analysis to identify intracellular parameters important in determining the specific antibody secretion rate and predict the dependen...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260390302
更新日期:1992-02-05 00:00:00
abstract::Trypsin and alpha-chymotrypsin were immobilized by gelentrapment in polyacrylamide cross-linked with N,N(1)-methylenebisacrylamide. The immobilized enzymes are catalytically efficient in suspensions of reverse micelles formed in isooctane by bis(2-ethylhexyl) sodium sulfosuccinate (AOT) and water. Both entrapped enzym...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260331008
更新日期:1989-04-20 00:00:00
abstract::Overexpression of recombinant proteins in Escherichia coli often leads to a severe growth retardation of the host cells. The phage T7 promoter phi10 in a pET vector was utilized to express human superoxide dismutase. Induction with IPTG lead to an increase in protein content and cell size and a termination of cell div...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10353
更新日期:2002-10-05 00:00:00
abstract::The bioartificial pancreas encapsulating pancreatic islets in immunoprotective hydrogel is a promising therapy for Type 1 diabetes. As pancreatic islets are highly metabolically active and exquisitely sensitive to hypoxia, maintaining O2 supply after transplantation remains a major challenge. In this study, we address...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26913
更新日期:2019-05-01 00:00:00
abstract::Beta defensins are antimicrobial peptides (AMPs) with a broad spectrum antimicrobial behavior against pathogens while having minimal tendency to incur pathogen resistance. Human β-defensin 28 (hBD28) is a strongly cationic AMP and hence hypothesized to be highly effective in permeabilizing negatively-charged pathogen ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22970
更新日期:2011-03-01 00:00:00
abstract::Autoflocculation and bioflocculation are considered to be the most promising means for the economical harvesting of microalgae. We have therefore studied these phenomena with cultures of Scenedesmus obliquus produced during biological tertiary wastewater treatment. The quantity of extracellular polymers produced durin...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260300707
更新日期:1987-11-01 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::Breast cancer cells experience a range of shear stresses in the tumor microenvironment (TME). However most current in vitro three-dimensional (3D) models fail to systematically probe the effects of this biophysical stimuli on cancer cell metastasis, proliferation, and chemoresistance. To investigate the roles of shear...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.27119
更新日期:2019-11-01 00:00:00
abstract::Supercritical fluid technology offers the possibility to produce dry powder formulations of biocompatible materials, overcoming the drawbacks of classical micronization processes. In this work, Supercritical Assisted Atomization (SAA) has been used to micronize alpha-cyclodextrin (alpha-CD) and hydroxypropyl-beta-cycl...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20895
更新日期:2006-07-05 00:00:00
abstract::MicroRNAs are small non-coding RNAs that play a critical role in post-transcriptional control of gene expression. Recent publications of genomic sequencing data from the Chinese Hamster (CGR) and Chinese hamster ovary (CHO) cells provide new tools for the discovery of novel miRNAs in this important production system. ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25539
更新日期:2015-07-01 00:00:00
abstract::The S-System formalism provides a popular, versatile and mathematically tractable representation of metabolic pathways. At steady-state, after a logarithmic transformation, the S-System representation reduces into a system of linear equations. Thus, the maximization of a particular metabolite concentration or a flux s...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19971020)56:2<145::AID-BIT
更新日期:1997-10-20 00:00:00
abstract::Dehydrogenase activity assay of activated sludge using the redox dye 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride (INT) was investigated. INT-dehydrogenase activity (INT-DHA) was directly proportional to INT dosage and inversely proportional to bio-mass concentration over limited ranges. INT dosages...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260280719
更新日期:1986-07-01 00:00:00
abstract::Oil residues arising from the Christos-Bitas spillage were found to contain 28% of oil extractable by carbon tetrachloride; the remainder consisted of water and undefined solids. Christos-Bitas mousse was added to 1.18 m(3) liquor inoculated with oil-contaminated marine mud, and aerated with a 1.5-hp vortex pump and v...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260270112
更新日期:1985-01-01 00:00:00
abstract::The growth dynamics of a methanol utilizing bacterium, L3, in batch bioreactors were experimentally investigated. Formaldehyde, a key intermediate of methanol oxidation, is indicated to have a significant role in the complex batch growth behavior of L3. The intricate batch growth dynamics of many microorganisms can be...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260261113
更新日期:1984-11-01 00:00:00
abstract::Efficient cofactor regeneration and reuse are highly desired for many important biotransformation applications. Here we show for the first time that cofactor NAD(H) covalently attached to micro particles, which can be easily recovered and reused, effectively mediated multistep reactions catalyzed by enzymes that were ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21584
更新日期:2008-02-15 00:00:00