Abstract:
:An immobilized enzyme (pancreatic ribonuclease bound to porous titania) was investigated for the degradation of purified yeast ribonucleic acid as a substrate. The immobilized enzyme is active and stable in the pH range 4--8. Dependence of enzymatic activity on ionic strength, pH, temperature, fluid flow rate, and substrate concentration were investigated. A cumulative fluid residence time of 6 sec is sufficient for 50% substrate conversion at 25 degrees C and pH 7.0. The critical flow rate (i.e., the fluid flow rate necessary to remove film diffusion resistance) approximately doubles with each 10 degree C rise in reaction temperature. The critical flow rates obtained in this study are about 40 times greater than those obtained for a similar study on immobilized glucose oxidase. Arrhenius plots gave activation energies of -9.6 and -7.1 kcal/g mol at pH 4.6 and 7.0, respectively. The work reported herein is a bench-scale investigation of an immobilized enzyme with primary emphasis on the mass transfer and kinetic characteristics of the system. The rapid reaction rates obtainable at relatively low temperatures offer a potential alternative method of purifying yeast single cell protein (SCP) with miminum loss of desired protein. The key questions are how such a system would react in a yeast homogenate, what conditions in such a system must be controlled, and what type of immobilized reactor should be utilized, if such further work continued to show promise.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Dale BE,White DHdoi
10.1002/bit.260210910subject
Has Abstractpub_date
1979-09-01 00:00:00pages
1639-48issue
9eissn
0006-3592issn
1097-0290journal_volume
21pub_type
杂志文章abstract::Using phage display technology, we have isolated 12-mer peptide ligands that bind to human blood outgrowth endothelial cells (HBOEC). To avoid non-specific binding we apply negative-positive selection approach by pre-incubating the library with non-HBOEC. The selected phage clones bind to their target cell population ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21420
更新日期:2007-09-01 00:00:00
abstract::Small interfering RNAs (siRNAs) are invaluable research tools for studying gene functions in mammalian cells. siRNAs are mainly produced by chemical synthesis or by enzymatic digestion of double-stranded RNA (dsRNA) produced in vitro. Recently, bacterial cells, engineered with ectopic plant viral siRNA binding protein...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26740
更新日期:2018-09-01 00:00:00
abstract::This article compares the processes for wheat straw lignocellulose fractionation by percolation, counter-current progressing batch percolation and batch reaction at low NaOH-loadings (3-6% of DM). The flow-through processes were found to improve delignification and subsequent enzymatic saccharification, reduce NaOH-co...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26030
更新日期:2016-12-01 00:00:00
abstract::In this study, the effects of the electric charges and fields on the viability of airborne microorganisms were investigated. The electric charges of different magnitude and polarity were imparted on airborne microbial cells by a means of induction charging. The airborne microorganisms carrying different electric charg...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10290
更新日期:2002-07-20 00:00:00
abstract::Current approaches for purifying plasmids from bacterial production systems exploit the physiochemical properties of nucleic acids in non-specific capture systems. In this study, an affinity system for plasmid DNA (pDNA) purification has been developed utilizing the interaction between the lac operon (lacO) sequence c...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20955
更新日期:2006-09-05 00:00:00
abstract::A sucrose utilization pathway was established in Ralstonia eutropha NCIMB11599 and R. eutropha 437-540 by introducing the Mannheimia succiniciproducens MBEL55E sacC gene that encodes β-fructofuranosidase. These engineered strains were examined for the production of poly(3-hydroxybutyrate) [P(3HB)] and poly(3-hydroxybu...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25469
更新日期:2015-03-01 00:00:00
abstract::Two general models for batch simultaneous enzymatic and microbial reaction (SEMR) processes are presented, the second derived from and simpler than the first and accounting for enzyme denaturation. Using the second model and parameter values from the literature, simulation was used to examine a range of enzyme additio...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260371114
更新日期:1991-05-01 00:00:00
abstract::Affinity chromatography using immobilized S-protein was used for the screening of affinity peptide ligands from two soluble peptide libraries. Peptide library I consisted of octamers with glycine (G) at both termini of each peptide, i.e. GXXXXXXG. The six center positions were constructed using random sequences of six...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:
更新日期:1999-06-20 00:00:00
abstract::The anaerobic digestion of a cellulose-enriched fraction of domestic refuse by means of rumen microorganisms in an "artificial rumen" digester was studied. Various combinations of solid and liquid retention times and loading rates were applied to establish optimum conditions for the acidogenic phase digestion of the r...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260320604
更新日期:1988-09-05 00:00:00
abstract::The nar promoter of Escherichia coli, which is maximally induced under anaerobic conditions in the presence of nitrate, was characterized to see whether the nar promoter cloned onto pBR322 can be used as an inducible promoter. To increase the expression level, the nar promoter was expressed in E. coli where active nit...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19961205)52:5<572::AID-BIT
更新日期:1996-12-05 00:00:00
abstract::Porcine pancreatic lipase and Fusarium solani cutinase were used to catalyze transesterification reactions between methyl propionate, ethyl propionate, and a series of primary alcohols at high temperatures in a continuous packed-bed gas-solid reactor, in which the solid phase is composed of the enzyme and the substrat...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260390415
更新日期:1992-02-20 00:00:00
abstract::Bioprocess identification starts with collection of process information. Usually there is a variety of information available, consisting of actual measurement data, historical data, empirical kinetic and yield correlations, and general knowledge available from literature. A central problem is to find out how the vario...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19960220)49:4<364::AID-BIT
更新日期:1996-02-20 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::Anaerobic biological wastewater treatment has numerous advantages over conventional aerobic processes; anaerobic biotechnologies, however, still have a reputation for low-quality effluents and operational instabilities. In this study, anaerobic bioreactors were augmented with an oxygen-transferring membrane to improve...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20219
更新日期:2005-02-20 00:00:00
abstract::A two-dimensional model for quantitative evaluation of the effect of convective and diffusive substrate transport on biofilm heterogeneity was developed. The model includes flow computation around the irregular biofilm surface, substrate mass transfer by convection and diffusion, biomass growth, and biomass spreading....
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/1097-0290(20000905)69:5<504::aid-bit5>3.0.
更新日期:2000-09-05 00:00:00
abstract::A mixed culture of sulfate-reducing bacteria containing the species Desulfovibrio desulfuricans was used to study sulfate-reduction stoichiometry and kinetics using ethanol as the carbon source. Growth yield was lower, and kinetics were slower, for ethanol compared to lactate. Ethanol was converted into acetate and no...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:
更新日期:2000-12-05 00:00:00
abstract::Several synthetic metabolic pathways for butanol synthesis have been reported in Escherichia coli by modification of the native CoA-dependent pathway from selected Clostridium species. These pathways are all dependent on the O2 -sensitive AdhE2 enzyme from Clostridium acetobutylicum that catalyzes the sequential reduc...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25324
更新日期:2015-01-01 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
abstract::D-Methionine was converted to L-methionine in a reaction system where four enzymes were used. D-amino acid oxidase (D-AAO) from Arthrobacter protophormiae was used for the complete conversion of D-methionine to 2-oxo-4-methylthiobutyric acid. Catalase was added to prevent 2-oxo-4-methylthiobutyric acid decarboxylation...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21501
更新日期:2007-12-01 00:00:00
abstract::Recombinant Escherichia coli JM101 was used for the in vivo biocatalytic synthesis of 3-tert-butyl- catechol. The bacterial strain synthesized the laboratory-evolved variant HbpA(T2) of 2-hydroxybiphenyl 3-monooxygenase (HbpA, EC 1.14.13.44) from Pseudomonas azelaica HBP1. The mutant enzyme HbpA(T2) is able to hydroxy...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10487
更新日期:2003-03-05 00:00:00
abstract::The rate of celluose degradation, limited due to the inhibition by cellobiose, can be increased by the hydrolysis of cellobiose to glucose using immobilized beta-glucosidase. Production of beta-glucosidase in four yeasts was studied and a maximum activity of 1.22 IU/mg cells was obtained in cells of Pichia etchellsii ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260260408
更新日期:1984-04-01 00:00:00
abstract::Potentially damaging reactive oxygen species (ROS) are involved in a number of pathways ranging from signal transduction to apoptosis. Cells have adapted this alteration in redox status into a complex regulatory mechanism. ROS are specifically able to induce the expression of a multitude of genes. We constructed and c...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20389
更新日期:2005-03-05 00:00:00
abstract::Physical damage of animal cells in suspension culture, due to stirring and sparging, is coupled with complex metabolic responses. Nylon microcapsules, therefore, were used as a physical model to study the mechanisms of damage in a stirred bioreactor and in a bubble column. Microcapsule breaskage folowed first-order ki...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260401018
更新日期:1992-12-05 00:00:00
abstract::Ultrafiltration through Carbosep M(4) mineral membrane of protein solutions of decreasing complexity (whey before and after centrifugation or clarification, beta-lactoglobulin) was studied. Mathematical models were used to explain variations in flux with time. Taking into account variations in protein retention and hy...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260340205
更新日期:1989-06-20 00:00:00
abstract::A new method for solid-state ethanol fermentation (the SSEF system) was experimented on for the ethanol production from solid starchy materials, where a packedbed-type fermentor was used. Both cultivation of Aspergillus saitoi and enrichment of a saccharifying enzyme were effective for hydrolysis of the starch. Ethano...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260270907
更新日期:1985-09-01 00:00:00
abstract::This study demonstrated that hydrogen-producing acidogenic sludge could agglutinate into granules in a well-mixed reactor treating a synthetic sucrose-containing wastewater at 26 degrees C, pH 5.5, with 6 h of hydraulic retention. A typical matured granule is 1.6 mm in diameter, 1.038 g/mL in density, 11% in ash conte...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10174
更新日期:2002-04-05 00:00:00
abstract::Addition of Tween 85 to aqueous suspensions of Anabaena variabilis induced photosynthetic evolution of hydrogen over a time span of several weeks: As much as 148 nmol H(2)/h . mg dry weight was produced in the first week by a suspension containing 4.2 mg dry weight of cells and 77 mM Tween 85. The chemical structure o...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260420812
更新日期:1993-10-01 00:00:00
abstract::Liquid membrane bilayers, generated by bacteriorhodopsin on a supporting membrane, exhibit photo osmosis. The phenomenon has been shown to be a consequence of light-induced electrical potential differences which develop across the liquid membrane bilayer due to the light-driven proton pumping action of bacteriorhodops...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260310602
更新日期:1988-04-20 00:00:00
abstract::An extensive investigation of anaerobic methane fermentation requires identifying the relationship between the physical environment and biological process. In this study, a computational fluid dynamics (CFD) technique was used to characterize bacterial fermentation mechanisms intertwined with mixing and heat transfer ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24551
更新日期:2012-11-01 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