Abstract:
:A balance between proliferation and cell death is critical for achieving desirable high cell densities in mammalian cell culture. In this study, we evaluate a recently discovered anti-apoptotic gene, aven, and examine its effectiveness alone and in combination with a member of the Bcl-2 family, bcl-xL. The commercially popular cell line, Chinese hamster ovary (CHO), was genetically modified to constitutively express aven, bcl-xL, and the two genes in combination. Cells were exposed to several model insults that simulate severe bioreactor environments, including serum deprivation, spent medium, and Sindbis virus infection, as well as staurosporine, a known chemical inducer of apoptosis. CHO cells exhibited DNA fragmentation, a hallmark of apoptosis, after exposure to these model insults. After exposure to serum deprivation, 4- and 5-day spent medium, and staurosporine, cells expressing Aven provided limited protection against cell death when compared with the protection afforded by cells expressing Bcl-xL alone. However, the highest survival levels for all insults were achieved when Aven was expressed in combination with Bcl-xL. In fact, Aven appeared to act synergistically to enhance the protective function of Bcl-xL for several insults, because the protective function of the two genes expressed together in one cell line often exceeded the additive protective levels of each anti-apoptosis gene expressed alone. Surprisingly, Aven expression provided a mildly pro-apoptotic response in CHO isolates infected with Sindbis virus. However, CHO cells expressing both Bcl-xL and Aven showed protection against Sindbis virus infection due to the inhibitory properties of the bcl-xL anti-apoptosis gene. This study shows that combinatorial anti-apoptosis cell engineering strategies may be the most effective mechanisms for providing extended protection against cell death in mammalian cell culture.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Figueroa B Jr,Chen S,Oyler GA,Hardwick JM,Betenbaugh MJdoi
10.1002/bit.10913subject
Has Abstractpub_date
2004-03-20 00:00:00pages
589-600issue
6eissn
0006-3592issn
1097-0290journal_volume
85pub_type
杂志文章abstract::A two-member methane-utilizing mixed culture of bacteria, formed by combining two pure cultures isolated from a naturally occurring methane-utilizing mixed culture, was studied in continuous culture. From the nutritional requirements and substrate ranges of the pure cultures, a mechanism for the interspecific interact...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260221010
更新日期:1980-10-01 00:00:00
abstract::It is shown that the mass transfer resistance can significantly distort the linearity of the Lineweaver-Burk plot of the kinetic data for a microbial culture which forms aggregates. For small flocs, the linearity of the Lineweaver-Burk plot is largely retained, but a different slope and intercept will be obtained comp...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260191204
更新日期:1977-12-01 00:00:00
abstract::Hemicellulose residues can be hydrolyzed into a sugar syrup using dilute mineral acids. Although this syrup represents a potential feedstock for biofuel production, toxic compounds generated during hydrolysis limit microbial metabolism. Escherichia coli LY01, an ethanologenic biocatalyst engineered to ferment the mixe...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(sici)1097-0290(1999)66:4<203::aid-bit1>3.
更新日期:1999-01-01 00:00:00
abstract::Cultural conditions optimum for beta-galactosidase production by Saccharomyces anamensis are pH 4.5, temperature 26 +/- 2 degrees C, and 30 h of incubation period. Addition of lactose at 24 h fermentation greatly increase the level of enzyme. Optimum pHl, temperature, pH stability, and thermostability of yeast beta-ga...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260240810
更新日期:1982-08-01 00:00:00
abstract::This article demonstrates the feasibility of a novel process concept for the remediation of PCB contaminated soil. The proposed process consists of PCB extraction from soil using solid polymer beads, followed by biodegradation of the extracted PCBs in a solid-liquid two-phase partitioning bioreactor (TPPB), where PCBs...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21674
更新日期:2008-04-01 00:00:00
abstract::Ralstonia eutropha grows on and produces polyhydroxyalkanoates (PHAs) from fermentation acids. Acetic acid, one major organic acid from acidogenesis of organic wastes, has an inhibitory effect on the bacterium at slightly alkaline pH (6 g HAc/L at pH 8). The tolerance of R. eutropha to acetate, however, was increased ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.1080
更新日期:2001-06-20 00:00:00
abstract::13C metabolic flux analysis (MFA) is based on carbon-labeling experiments where a specifically (13)C labeled substrate is fed. The labeled carbon atoms distribute over the metabolic network and the label enrichment of certain metabolic pools is measured by using different methods. Recently, MS methods have been dramat...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10909
更新日期:2004-02-05 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::Catalytic activity of lipases (from Rhizopus arrhizus, Canadida rugosa, and Pseudomonas sp. was studied in organic media, mainly diisopropyl ether. The effect of water activity (a(w)) on V(max) showed that the enzyme activity in general increased with increasing amounts of water for the three enzymes. This was shown b...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19970905)55:5<798::AID-BIT
更新日期:1997-09-05 00:00:00
abstract::Increased stability at alkaline pH should be a valuable attribute for the utilization of penicillin acylase in bioreactors employed to convert penicillins into 6-aminopenicillanic acid, a precursor of semisynthetic penicillins. In these systems, base is added for pH control, which results in local alkaline conditions ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260480208
更新日期:1995-10-20 00:00:00
abstract::Enzymatic hydrolysis of arabinoxylan is an important prerequisite for the utilization of hemicellulose for ethanol fermentation or for making the low calorie sweetener xylitol by catalytic hydrogenation of the generated xylose. This study focus on cloning and characterization of two industrial relevant beta-xylosidase...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20908
更新日期:2006-08-05 00:00:00
abstract::Recent environmental concerns have prompted a re-evaluation of conventional management strategies and refueled the search of innovative waste management practices. In this sense, the anaerobic digestion of both fat and the remaining complex organic matter present in dairy wastewaters is attractive, although the contin...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21095
更新日期:2007-02-01 00:00:00
abstract::Installing membranes for solid-liquid separation into biological nutrient removal (BNR) activated sludge (AS) systems makes a profound difference not only in the design of the BNR system itself, but also in the design approach for the whole wastewater treatment plant (WWTP). In multizone BNR systems with membranes in ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20311
更新日期:2005-03-20 00:00:00
abstract::Biosensors with animal and microbial cells immobilized close to the tip of a membrane electrode have been developed for chemical and drug testing. Our experimental results show that biosensors can be used for drug screening and to provide useful information about various cell-chemical interactions. A computer aided an...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260310311
更新日期:1988-02-20 00:00:00
abstract::Aspergillus awamori NRRL 4869 was cultured on the solid substrate, wheat bran, in a modified Rollacell apparatus to produce alpha-galactosidase and invertase. The swivel cap on the elongated bottle permits the introduction of air while the bottle rotates. Parameters of air flow rate (0.05-0.2 liter/kg/min), rpm (0.15-...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260220213
更新日期:1980-02-01 00:00:00
abstract::In this study, we assessed the importance of cytoskeleton organization in the mammalian cells used to produce therapeutic proteins. Two cytoskeletal genes, Actin alpha cardiac muscle 1 (ACTC1) and a guanosine triphosphate GTPase-activating protein (TAGAP), were found to be upregulated in highly productive therapeutic ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.27277
更新日期:2020-04-01 00:00:00
abstract::Cell morphology is an important macroscopic indicator of cellular physiology and is increasingly used as a mean of probing culture state in vitro. Phase contrast microscopy (PCM) is a valuable tool for observing live cells morphology over long periods of time with minimal culture artifact. Two general approaches are c...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26064
更新日期:2017-01-01 00:00:00
abstract::Rapid fermentation of cane molasses into ethanol has been studied in batch, continuous (free-cell and cell-immobilized systems) by a strain of Saccharomyces cerevisiae at temperature 30 degrees C and pH 5.0. The maximum productivity of ethanol obtained in immobilized system was 28.6 g L(-1) h(-1). The cells were immob...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260240403
更新日期:1982-04-01 00:00:00
abstract::Adsorption of cellulases onto lignin is considered a major factor in retarding enzymatic cellulose degradation of lignocellulosic biomass. However, the adsorption mechanisms and kinetics are not well understood for individual types of cellulases. This study examines the binding affinity, kinetics of adsorption, and co...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26820
更新日期:2018-12-01 00:00:00
abstract::Trehalase is the enzyme which hydrolyzes the disaccharide trehalose into two alpha-D-glucose molecules. In this article, we present the immobilization of trehalase on aminopropyl glass particles. The enzyme was extracted from Escherichia coli Mph2, a strain harboring the pTRE11 plasmid, which contains the trehalase ge...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19970405)54:1<33::AID-BIT4
更新日期:1997-04-05 00:00:00
abstract::Various structure-similar plant secondary metabolites like ginseng saponins (ginsenosides) possess different or even totally opposite biological activities. Intentional manipulation of the ginsenoside heterogeneity in cellular biosynthesis is of great interest and significance [Zhong and Yue (2005); Adv Biochem Eng Bi...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21829
更新日期:2008-08-01 00:00:00
abstract::We investigated the role of green sulfur bacteria inlight-responsive electricity generation in microbial electrochemical cells (MXCs). We operated MXCs containing either monocultures or defined cocultures of previously enriched phototrophic Chlorobium and anode-respiring Geobacter under anaerobic conditions in the abs...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25011
更新日期:2014-02-01 00:00:00
abstract::The kinetic properties of acetate-degrading methanogenic granular sludge of different mean diameters were assessed at different up-flow velocities (V(up)). Using this approach, the influence of internal and external mass transfer could be estimated. First, the apparent Monod constant (K(S)) for each data set was calcu...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.1044
更新日期:2001-04-20 00:00:00
abstract::Regenerative medicine has emerged as an important discipline that aims to repair injury or replace damaged tissues or organs by introducing living cells or functioning tissues. Successful regenerative medicine strategies will likely depend upon a simultaneous optimization strategy for the design of biomaterials, cell-...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26452
更新日期:2018-01-01 00:00:00
abstract::The sec-alcohol dehydrogenase activity of whole cells of Rhodococcus ruber DSM 44541 has been employed as an efficient biocatalytic redox system due to the use of acetone and 2-propanol at elevated concentrations for cofactor regeneration in the oxidation and reduction mode, respectively, and external addition of NADH...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10540
更新日期:2003-03-30 00:00:00
abstract::Enzyme engineering is a powerful tool to fine-tune the enzymes. It is a technique by which the stability, activity, and specificity of the enzymes can be altered. The characteristic properties of an enzyme can be amended by immobilization and protein engineering. Among them, protein engineering is the most promising, ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章,评审
doi:10.1002/bit.27329
更新日期:2020-06-01 00:00:00
abstract::Recent studies have demonstrated the feasibility of using ultrafiltration for the purification of plasmid DNA, but there is still little understanding of the factors governing DNA transmission. Experimental data were obtained for the transmission of a 3.0 kbp supercoiled plasmid DNA through composite regenerated cellu...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21575
更新日期:2008-02-01 00:00:00
abstract::Surface plasmon resonance (SPR) technique was used to directly detect an intact form of insect pathogen: the baculovirus, Autographa californica multiple nuclear polyhedrosis virus (AcMNPV). An SPR sensor chip with three bio-functional layers was used to detect the intact AcMNPV: amine-reactive crosslinker with a disu...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20882
更新日期:2006-07-05 00:00:00
abstract::Studies have been conducted in a gas circulation type fermentor in order to characterize the ethanol fermentation of uncooked cassava starch with Rhizopus koji. Results showed that ethanol concentration reached 13-14% (v/v) in 4-day broth, and the maximum productivity of ethanol was 2.3 g ethanol/L broth h. This produ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260270823
更新日期:1985-08-01 00:00:00
abstract::We studied the resolution of racemic glycidol through esterification with butyric acid catalyzed by porcine pancreatic lipase in organic media. A screening of seven solvents (log P values between 0.49 and 3.0, P being the n-octanol-water partition coefficient of the solvent) showed that neither log P nor the logarithm...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260420409
更新日期:1993-08-05 00:00:00