Abstract:
:Metabolic carbon labelling experiments enable a large amount of extracellular fluxes and intracellular carbon isotope enrichments to be measured. Since the relation between the measured quantities and the unknown intracellular metabolic fluxes is given by bilinear balance equations, flux determination from this data set requires the numerical solution of a nonlinear inverse problem. To this end, a general algorithm for flux estimation from metabolic carbon labelling experiments based on the least squares approach is developed in this contribution and complemented by appropriate tools for statistical analysis. The linearization technique usually applied for the computation of nonlinear confidence regions is shown to be inappropriate in the case of large exchange fluxes. For this reason a sophisticated compactification transformation technique for nonlinear statistical analysis is developed. Statistical analysis is then performed by computing appropriate statistical quality measures like output sensitivities, parameter sensitivities and the parameter covariance matrix. This allows one to determine the order of magnitude of exchange fluxes in most practical situations. An application study with a large data set from lysine-producing Corynebacterium glutamicum demonstrates the power and limitations of the carbon-labelling technique. It is shown that all intracellular fluxes in central metabolism can be quantitated without assumptions on intracellular energy yields. At the same time several exchange fluxes are determined which is invaluable information for metabolic engineering.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Wiechert W,Siefke C,de Graaf AA,Marx Adoi
10.1002/(SICI)1097-0290(19970705)55:1<118::AID-BITsubject
Has Abstractpub_date
1997-07-05 00:00:00pages
118-35issue
1eissn
0006-3592issn
1097-0290journal_volume
55pub_type
杂志文章abstract::Growth decoupling can be used to optimize the production of biochemicals and proteins in cell factories. Inhibition of excess biomass formation allows for carbon to be utilized efficiently for product formation instead of growth, resulting in increased product yields and titers. Here, we used CRISPR interference to in...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.27536
更新日期:2020-08-18 00:00:00
abstract::Proteolysis associated with recombinant protein expression in Chinese Hamster Ovary (CHO) cells has hindered the development of biologics including HIV vaccines. When expressed in CHO cells, the recombinant HIV envelope protein, gp120, undergoes proteolytic clipping by a serine protease at a key epitope recognized by ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.27016
更新日期:2019-09-01 00:00:00
abstract::Benzil was reduced stereospecifically to (S)-benzoin by Bacillus cereus strain Tim-r01. To isolate the gene responsible for asymmetric reduction, we constructed a library consisting of Escherichia coli clones that harbored plasmids expressing Bacillus cereus genes. The library was screened using the halo formation ass...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.1191
更新日期:2001-12-20 00:00:00
abstract::Control of cell shape and behavior through the micropattern technique by spatial immobilization of adhesive proteins on a surface has provided novel insights in several aspects of cell biology, such as tissue morphogenesis, cell growth and cell differentiation, and apoptosis. In this work, we present the use of poly(e...
journal_title:Biotechnology and bioengineering
pub_type: 信件
doi:10.1002/bit.22997
更新日期:2011-04-01 00:00:00
abstract::Bacterial magnetic particles (BMPs) were used for the identification of cyanobacterial DNA. Genus-specific oligonucleotide probes for the detection of Anabaena spp., Microcystis spp., Nostoc spp., Oscillatoria spp., and Synechococcus spp. were designed from the variable region of the cyanobacterial 16S rDNA of 148 str...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.1073
更新日期:2001-06-05 00:00:00
abstract::Production of conidia of the biocontrol fungus Coniothyrium minitans by solid-state cultivation in a packed-bed reactor on an industrial scale is feasible. Spore yield and oxygen consumption rate of C. minitans during cultivation on oats and three inert solids (hemp, perlite, and bagasse) saturated with a liquid mediu...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(sici)1097-0290(19991120)65:4<447::aid-bit
更新日期:1999-11-20 00:00:00
abstract::At the laboratory scale, sudden step increases from 30 to 42 degrees C can be readily accomplished when expressing heterologous proteins in heat-inducible systems. However, for large scale-cultures only slow ramp-type increases in temperature are possible due to heat transfer limitations, where the heating rate decrea...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22084
更新日期:2009-02-01 00:00:00
abstract::A limited life cycle assessment (LCA) was performed on a combined biological and chemical process for the production of adipic acid, which was compared to the traditional petrochemical process. The LCA comprises the biological conversion of the aromatic feedstocks benzoic acid, impure aromatics, toluene, or phenol fro...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.23074
更新日期:2011-06-01 00:00:00
abstract::Although sophorolipids (SLs) produced by S. bombicola are a real showcase for the industrialization of microbial biosurfactants, some important drawbacks are associated with this efficient biological process, e.g., the simultaneous production of acidic and lactonic SLs. Depending on the application, there is a require...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25815
更新日期:2016-03-01 00:00:00
abstract::A novel deuterium ((2)H) NMR technique as developed for measuring the total number of deuterons exchanged by lyophilised protein samples following hydrogen-deuterium (H-D) exchange. Using this methodology differences in the H-D exchange behaviour of the proteolytic enzyme subtilisin Carlsberg hydrated either in air or...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:
更新日期:2000-11-05 00:00:00
abstract::The enantiocatalytic performance of immobilized lipase in an emulsion membrane reactor using stable emulsion prepared by membrane emulsification technology was studied. The production of optical pure (S)-naproxen from racemic naproxen methyl ester was used as a model reaction system. The O/W emulsion, containing the s...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10826
更新日期:2003-12-20 00:00:00
abstract::While many pretreatments attempt to improve the enzymatic digestibility of biomass by removing lignin, this study shows that improving the surface area accessible to cellulase is a more important factor for achieving a high sugar yield. Here we compared the pretreatment of switchgrass by two methods, cellulose solvent...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22919
更新日期:2011-01-01 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::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
abstract::Extracellular beta-xylosidase (1,4-beta-D-xylan xylohydrolase, EC 3.2.1.37) from culture filtrates of Neurospora crassa was purified to homogeneity by preparative isoelectric focusing followed by gel electrophoresis. The molecular weight of the purified xylosidase was 83,000 D and the K(m) on p-nitrophenyl-beta-D-xylo...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260281210
更新日期:1986-12-01 00:00:00
abstract::We study the role of nano-scale cues in controlling neuronal growth. We use photolithography to fabricate substrates with repeatable line-pattern ridges of nano-scale heights. We find that neuronal processes, which are of micron size, have strong interactions with ridges even as low as 10 nm. The interaction between t...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24444
更新日期:2012-07-01 00:00:00
abstract::The methanol-regulated alcohol oxidase promoter (PAOX1 ) of Pichia pastoris (syn. Komagataella spp. ) is one of the strongest promoters for heterologous gene expression. Although increasing the gene dosage is a common strategy to improve recombinant protein productivities, P. pastoris strains harboring more than two c...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26947
更新日期:2019-07-01 00:00:00
abstract::3-Dehydroshikimic acid (DHS), in addition to being a potent antioxidant, is the key hydroaromatic intermediate in the biocatalytic conversion of glucose into aromatic bioproducts and a variety of industrial chemicals. Microbial synthesis of DHS, like other intermediates in the common pathway of aromatic amino acid bio...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:
更新日期:1999-07-05 00:00:00
abstract::A novel technique for immobilization of Candida rugosa lipase onto anionic colloidal gas aphrons (CGAs) is described. CGAs are spherical microbubbles (10-100 microm) composed of an inner gas core surrounded by a surfactant shell. In this initial study, greater than 80% lipase (w/w) was effectively retained on the CGAs...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.1116
更新日期:2001-08-05 00:00:00
abstract::Incremental truncation is a method for constructing libraries of every one base pair truncation of a segment of DNA. Incremental truncation libraries can be created using a time-dependent nuclease method or through the incorporation of alpha-phosphothioate dNTPs by PCR or by primer extension (THIO(pcr) truncation and ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10604
更新日期:2003-06-05 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::Nucleotide sugar-dependent ("Leloir") glycosyltransferases (GTs), represent a new paradigm for the application of biocatalytic glycosylations to the production of fine chemicals. However, it remains to be shown that GT processes meet the high efficiency targets of industrial biotransformations. We demonstrate in this ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26204
更新日期:2017-04-01 00:00:00
abstract::Two-dimensional image analysis was applied to counting, sizing, and density determinations of granules in full-scale and laboratory-scale upflow anaerobic sludge blanket (UASB) digesters. An advantage of this technique for monitoring laboratory-scale digester sludge is the small amount of material required for analysi...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260420303
更新日期:1993-07-01 00:00:00
abstract::10-Deacetylabaccatin III (10 DAB), an important precursor for paclitaxel semisynthesis, is enhanced in yew extracts using C10-deacetylase and C13-deacylase enzymes.(4) C10-deacetylase is an intracellular enzyme produced by the fermentation of a soil microorganism, Nocardioides luteus (SC 13912). During the fermentatio...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260480518
更新日期:1995-12-05 00:00:00
abstract::PER.C6 cells were cultivated for propagation of a replication-defective adenovirus vector in serum-free suspension bioreactors. Cellular metabolism during cell growth and adenovirus propagation was fully characterized using on-line and off-line methods. The energy metabolism was found to accelerate transiently after a...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20455
更新日期:2005-06-05 00:00:00
abstract::A drug-releasing model compound based on photosensitive acrylated ortho-nitrobenzylether (o-NBE) moiety and fluorescein was synthesized to demonstrate photolysis as a mechanism for drug release. Release of this model compound from a hydrogel network can be controlled with light intensity (5-20 mW/cm(2)), exposure dura...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22882
更新日期:2010-12-15 00:00:00
abstract::The implementation of control algorithms to batch bioreactors is often complicated by variations in process dynamics that occur during the course of fermentation. Such a wide operating range often renders the performance of fixed gain proportional-integral-differential (PID) controllers unsatisfactory. In this work, d...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260320415
更新日期:1988-08-05 00:00:00
abstract::An immobilized enzyme reactor has been developed to remove heparin, the anticoagulant that is required in all extracorporeal devices for patients undergoing open-heart surgery or kidney dialysis. The device uses the enzyme heparinase (EC 4.2.2.7), which is covalently linked to agarose with cyanogen bromide. A critical...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260300209
更新日期:1987-08-05 00:00:00
abstract::The transesterification reaction of N-acetyl-L-phenylalanine ethyl ester with 1-propanol catalyzed by alpha-chymotrypsin was examined in the ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF(6)]) and 1-octyl-3-methylimidazolium hexafluorophosphate ([omim][PF(6)]), and in combination with supercr...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.1177
更新日期:2001-10-20 00:00:00
abstract::Abnormal airway mucus presents a significant challenge for inhalational drug delivery. Recognizing the thick and tenacious airway mucus seen in the cystic fibrosis (CF) patients as a critical barrier to effective drug delivery, both into the mucus layer itself as well as across that layer to the underlying airway epit...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.23046
更新日期:2011-06-01 00:00:00