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 continuous culture of hybridoma cells. For the hybridoma cells, the sensor showed a good correlation with the biomass concentration. However, this was not the case for the Vero cells. As soon as glutamine was exhausted, the biomass activity stabilized, whereas the amount of biomass almost doubled. Because the sensor developed responds to nutrient limitations much faster than becomes visible through cell density measurements, and because the volumetric biomass activity can be related to the volumetric consumption rates and production rates of important metabolites, it shows excellent possibilities for control purposes.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Dorresteijn RC,Numan KH,de Gooijer CD,Tramper J,Beuvery ECdoi
10.1002/(SICI)1097-0290(19960720)51:2<206::AID-BITsubject
Has Abstractpub_date
1996-07-20 00:00:00pages
206-14issue
2eissn
0006-3592issn
1097-0290journal_volume
51pub_type
杂志文章abstract::Cost-effective production of biopharmaceuticals on a large scale can be carried out by perfusion cultures of mammalian cells. One problem with this mode of operation for submerged free-cell cultures is the requirement for an efficient cell separation device located in the effluent stream. The present work investigates...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19970505)54:3<239::AID-BIT
更新日期:1997-05-05 00:00:00
abstract::Relatively conservative modifications of three proteins were carried out to alter their surface properties. The protein properties modified were hydrophobicity and charge. This was done by acylation of amino groups with anhydrides. For the hydrophobic modification experiments, two proteins (beta-lactoglobulin and bovi...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19960205)49:3<290::AID-BIT
更新日期:1996-02-05 00:00:00
abstract::At the most fundamental level, saccharification occurs when cell wall degrading enzymes (CWDEs) diffuse, bind to and react on readily accessible cellulose fibrils. Thus, the study of the diffusive behavior of solutes into and out of cellulosic substrates is important for understanding how biomass pore size distributio...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24958
更新日期:2013-11-01 00:00:00
abstract::Relative levels of many individual proteins in Escherichia coli HB101 strains with 0, 37, 56, and 240 plasmids per chromosome were determined by computer image analysis of two-dimensional gel electrophoresis patterns. The plasmids investigated had very similar sequences except for small domains encoding the repressor ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260370808
更新日期:1991-04-05 00:00:00
abstract::For the application of immobilized enzymes, fixed bed reactors are used almost exclusively. Fixed bed reactors have specific disadvantages, especially for processes with a deactivating catalyst. Therefore, we have studied a novel reactor type with continuous transport of the immobilized biocatalyst. Flow of biocatalys...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260360407
更新日期:1990-08-05 00:00:00
abstract::Utilising whole cells of recombinant Escherichia coli K27 (pCYP102, pGEc47) containing active cytochrome P450BM-3 monooxygenase [E.C. 1. 14.14.1], multiple oxidations of saturated and unsaturated fatty acids were performed by the enzyme under conditions of excess oxygen. The amount of oxygen dissolved in the culture m...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(sici)1097-0290(19990805)64:3<333::aid-bit
更新日期:1999-08-05 00:00:00
abstract::A gene coding for human parathyroid hormone (hPTH) was synthesized and cloned into a yeast expression and secretion vector containing the mating factor alpha pre-pro leader sequence and the galactose-inducible promoter, GAL10. The intact hPTH(1-84) was found to be secreted into the culture medium. As observed in the p...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(sici)1097-0290(19980120)57:2<245::aid-bit
更新日期:1998-01-20 00:00:00
abstract::Nitrifying bacteria, cyanobacteria, and algae are important microorganisms in open pond wastewater treatment systems. Nitrification involving the sequential oxidation of ammonia to nitrite and nitrate, mainly due to autotrophic nitrifying bacteria, is essential to biological nitrogen removal in wastewater and global n...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22860
更新日期:2010-12-15 00:00:00
abstract::A pure culture of Pseudomonas fluorescens was used as a model system to study the kinetics of denitrification. An exponentially growing culture was harvested and resuspended in an anoxic acetate solution buffered with K/Na phosphate at pH values of 6.6, 7.0, 7.4, and 7.8. The temperature was kept at 28 degrees C in al...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260460512
更新日期:1995-06-05 00:00:00
abstract::Trypsin inhibitor was converted to hydrophobic states by covalently combining cholesteryl groups using an acylation reaction, and was immobilized in reverse micelles composed of a nonionic surfactant. Using this reverse micellar phase containing trypsin inhibitor as an affinity ligand, trypsin was selectively separate...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19970220)53:4<406::AID-BIT
更新日期:1997-02-20 00:00:00
abstract::The cell cycle dependency of foreign gene expression in recombinant mouse L cells was investigated. Two different recombinant mouse L cell lines having the glucocorticoid receptor-encoding gene and the lacZ reporter gene were used in this study. The lacZ gene expression was controlled by the glucocorticoid-inducible m...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19960505)50:3<229::AID-BIT
更新日期:1996-05-05 00:00:00
abstract::Continuous manufacturing is currently being seriously considered in the biopharmaceutical industry as the possible new paradigm for producing therapeutic proteins, due to production cost and product quality related benefits. In this study, a monoclonal antibody producing CHO cell line was cultured in perfusion mode an...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26069
更新日期:2017-02-01 00:00:00
abstract::The production of recombinant proteins by mammalian cells demands a highly controlled environment for cell cultivation. Temperature stress represents a commonly encountered disturbance in both research and process environments. In this study, we examined the effects of heat shock on the expression of recombinant human...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260401008
更新日期:1992-12-05 00:00:00
abstract::Multivalent cations have been known to be important components of activated sludge floc structure due to their bridging ability of the negatively charged sites on the biopolymer network. Recently in batch systems it was found that excess concentration of monovalent cations led to the deterioration in settleability, de...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21755
更新日期:2008-06-01 00:00:00
abstract::Frozen bagged seed inoculum was prepared, thawed and tested for seven cultures. Thawing techniques were developed and other key influences on thawing rate were quantified; seed bag thawing without a water bath rarely required more than 4 to 5 h and was as short as 0.5 to 1 h for lower fill volume bags. Testing include...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10323
更新日期:2002-09-20 00:00:00
abstract::Among various routes for the biological hydrogen production, the NAD(P)H-dependent pentose phosphate (PP) pathway is the most efficient for the dark fermentation. Few studies, however, have focused on the glucose-6-phosphate 1-dehydrogenase, encoded by zwf, as a key enzyme activating the PP pathway. Although the gluco...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.23259
更新日期:2011-12-01 00:00:00
abstract::Recently, we reported that the loss of a telomeric region of chromosome 8 in Chinese Hamster Ovary (CHO) cells correlates with higher recombinant productivities. New cell lines lacking this region, called CHO-C8DEL, showed several advantages during cell line generation and for the production of recombinant proteins (R...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26009
更新日期:2016-11-01 00:00:00
abstract::Mixed culture of microorganisms immobilized onto Celite diatomaceous earth particles were used to degrade 3,4-dichloroaniline (34DCA) in a three-phase draft tube fluidized bed bioreactor. Biodegradation was confirmed as the dominant removal mechanism by measurements of the concomitant chloride ion evolution. Degradati...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260380308
更新日期:1991-07-01 00:00:00
abstract::Agility to schedule and execute cell culture manufacturing campaigns quickly in a multi-product facility will play a key role in meeting the growing demand for therapeutic proteins. In an effort to shorten campaign timelines, maximize plant flexibility and resource utilization, we investigated the initiation of cell c...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24808
更新日期:2013-05-01 00:00:00
abstract::The bacterial consortium MPD-M, isolated from sediment associated with Colombian mangrove roots, was effective in the treatment of hydrocarbons in water with salinities varying from 0 to 180 g L(-1). Where the salinity of the culture medium surpassed 20 g L(-1), its effectiveness increased when the cells were immobili...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10318
更新日期:2002-07-20 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::A model that portrays substrate profiles in a steady-state multispecies granular biofilm is developed and coupled with a biofilm detachment model. The model accounts for glucose, propionate, hydrogen, and acetate transformations performed by three bacterial trophic groups: acidogens, syntrophic bacterial consortia, an...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19970420)54:2<122::AID-BIT
更新日期:1997-04-20 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::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 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
abstract::A novel endoglucanase gene, celM , was cloned from a thermal spring metagenome. The gene was expressed in Escherichia coli, and the protein was extracted and purified. The protein catalyzed the hydrolysis of amorphous cellulose in a wide range of temperatures, 30-95°C, with optimal activity at 80°C. It was able to tol...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.27668
更新日期:2021-01-06 00:00:00
abstract::Genetically-engineered cells offer a solution to the cell availability problem in tissue engineering a pancreatic substitute for the treatment of insulin-dependent diabetes. These cells can be non-beta cells, such as hepatocytes or myoblasts, retrieved as a biopsy from the same patient and genetically engineered to se...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20817
更新日期:2006-04-20 00:00:00
abstract::The enzymatic synthesis of polyesters from activated diesters and diols has been investigated. Differences between enzymatic synthesis and traditional chemical condensation processes are discussed. The disappearance of monomers during the initial phase of reaction indicates that enzyme has a higher specificity for tra...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19970705)55:1<227::AID-BIT
更新日期:1997-07-05 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::In our previous study [Hong Y, Brown DG (2009) Appl Environ Microbiol 75(8):2346-2353], the adenosine triphosphate (ATP) level of adhered bacteria was observed to be 2-5 times higher than that of planktonic bacteria. Consequently, the proton motive force (Delta p) of adhered bacteria was approximately 15% greater than...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22606
更新日期:2010-04-01 00:00:00