Abstract:
:Cross-linked polyurethane (PU) was prepared for entrapping thermolysin. Using the immobilized thermolysin (IT), Z-L-aspartic acid (ZA) was reacted with -Lphenylalanine methyl ester (L-PM) in water-saturated ethyl acetate to give only alpha-Z-L-aspartylL-phenylalanine methyl ester (alpha-ZAPM). Ninety-four percent conversion of alpha-ZAPM was obtained for 30 h of reaction at 40 degrees C when 46 mg of enzyme was entrapped. PU support prepared from polypropylene glycol (#2000) showed better properties than from polypropylene (#1000) and polyethylene (#1000). Addition of polyol could increase the gel fraction of PU. The IT PU-ll-G-3, prepared from 1/2 mole ratio of PPG (#2000)/glycerin, gave the highest gel fraction and best swelling, and 89.0% of residual activity was obtained after four times of reuse (72 h). The stability of immobilized thermolysin was good; the activity loss resulting from degradatin and leak of enzyme in each time of reuse were found only about 2%. The kinetics of immobilized thermolysin-catalyzed condensation reaction of ZA with L-PM in water-saturated ethyl acetate was found to be first order in L-PM and the Lineweaver-Burk plot of 1/V against 1/[ZA] yields a straight line, showing that the reaction involves consecutive reactions of ZA and L-PM with the immobilized enzyme and with the ZA-immobilized enzyme complex, with the second reaction being the rate determining step.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Yang CP,Su CSdoi
10.1002/bit.260320504subject
Has Abstractpub_date
1988-08-20 00:00:00pages
595-603issue
5eissn
0006-3592issn
1097-0290journal_volume
32pub_type
杂志文章abstract::Derivatives of Escherichia coli C were engineered to produce primarily succinate or malate in mineral salts media using simple fermentations (anaerobic stirred batch with pH control) without the addition of plasmids or foreign genes. This was done by a combination of gene deletions (genetic engineering) and metabolic ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21694
更新日期:2008-04-01 00:00:00
abstract::A facile methodology has been developed for covalently derivatizing the surfaces of common materials with a designed antibacterial polycation, poly(vinyl-N-pyridinium bromide), wherein the first, key step involves surface coating with a nanolayer of silica. Various commercial synthetic polymers derivatized in this man...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10299
更新日期:2002-08-20 00:00:00
abstract::A model that was used to describe toxicity from high concentrations of chlorinated aliphatic hydrocarbons (CAHs) on reductively dechlorinating cultures in batch reactors (Sabalowsky and Semprini (in press)) was extended here to simulate observations in continuous flow suspended and attached growth reactors. The reduct...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22822
更新日期:2010-10-15 00:00:00
abstract::The engineering of production cell lines to express anti-apoptotic genes has been pursued in recent years due to potential process benefits, including enhanced cell survival, increased protein expression, and improved product quality. In this study, a baby hamster kidney cell line secreting recombinant factor VIII (BH...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21479
更新日期:2007-11-01 00:00:00
abstract::The mouse mammary tumor virus (MMTV) promoter is induced by the addition of a glucocorticoid hormone or analog such as dexamethasone. The hormone binds to its specific transcription factor, glucocorticoid receptor (GR), and the activated complex then binds to the glucocorticoid response elements (GREs) in the enhancer...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:
更新日期:2000-01-20 00:00:00
abstract::A comparative study of antimicrobial activity is done using three different electrospun nanofibers namely-CA, PAN, and PVC used as control and with various amounts of AgNO(3) being treated with UV-irradiation leading to the enhancement of silver nanoparticles. DMF is used as the common solvent which helps to undergo s...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21351
更新日期:2007-08-15 00:00:00
abstract::Melanoma is now the fifth most common type of cancer in North America. At present, there is no optimal treatment for this cancer. However, the lowering of the tyrosine level can inhibit the growth of melanoma. Unfortunately, this diet restriction cannot be humanly tolerated and causes vomiting, nausea, and severe body...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20084
更新日期:2004-06-30 00:00:00
abstract::A recombinant strain of Salmonella enterica serovar Typhimurium (mutant in propionate-activation activity) was metabolically engineered to control the composition of poly(3-hydroxybutyrate-co-3-hydroxy- valerate) (PHBV), a polyhydroxyalkanoate copolymer with commercially desirable properties. A gene (prpE) encoding pr...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.1150
更新日期:2001-09-01 00:00:00
abstract::In this study we describe a model that estimates the extracellular (nonfungal) and overall water contents of wheat grains during solid-state fermentation (SSF) with Aspergillus oryzae, using on-line measurements of oxygen, carbon dioxide, and water vapor in the gas phase. The model uses elemental balances to predict s...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/1097-0290(20000120)72:2<231::aid-bit11>3.0
更新日期:2001-01-20 00:00:00
abstract::Plant cell walls are composed primarily of cellulose, hemicelluloses, lignins, and pectins. Of these components, lignins exhibit unique chemistry and physiological functions. Although lignins can be used as a product feedstock or as a fuel, lignins are also generally seen as a barrier to efficient enzymatic breakdown ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21959
更新日期:2008-12-01 00:00:00
abstract::Continous culture experiments with the obligatory methanotroph, Methylosinus trichosporium OB3b, were conducted to study the whole-cell methane monooxygenase (MMO) and nitrogenase activities in a nitrate minimal salts medium under oxygen-limited conditions with methane as the carbone source. The important variables in...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260400609
更新日期:1992-09-01 00:00:00
abstract::Metabolic engineering of isopropyl alcohol (IPA)-producing Escherichia coli strains was conducted along with 13 C-metabolic flux analysis (MFA). A metabolically engineered E. coli strain expressing the adc gene derived from Clostridium acetobutylicum and the IPADH gene from C. beijerinckii did not produce IPA during i...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26390
更新日期:2017-12-01 00:00:00
abstract::Constitutive activation of Wnt signaling plays an important role in colorectal and liver tumorigenesis. Cell-based assays using synthetic TCF/LEF (T-cell factor/lymphoid enhancer factor) reporters, as readouts of β-catenin/TCF-dependent transcriptional activity, have contributed greatly to the discovery of small molec...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26394
更新日期:2017-12-01 00:00:00
abstract::Zwittermicin A (ZwA), a hybrid polyketide- peptide antibiotic, and N-acyl -homoserine-lactonase (AHL-lactonase), a kind of quorum-quenching enzyme, have the potential to prevent the virulence of Erwinia carotovora, which is a major pathogen of soft rot. The purpose of this study was to combine the two agents in one ho...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21794
更新日期:2008-06-15 00:00:00
abstract::Extractive work-up of whole-cell biotransformations generally suffers from the formation of stable gels and slimes upon addition of the organic solvent to the cell suspension and the cell-free solution, respectively. This problem has been overcome by enzymatic lysis of emulsifying agents present in the medium through ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20155
更新日期:2004-08-20 00:00:00
abstract::The reaction kinetics for phenol biodegradation at low substrate concentrations can be estimated based on the analysis of changes in the dissolved oxygen concentration in the bulk liquid during biodegradation. The measured oxygen concentration changes with an interesting behavior as biodegradation proceeds. The oxygen...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19960620)50:6<709::AID-BIT
更新日期:1996-06-20 00:00:00
abstract::Buddleja davidii is a unique biomass that has many attractive agroenergy features, especially its wide range of growth habitat. The anatomical characteristics of B. davidii were investigated before and after ethanol organosolv pretreatment (one of the leading pretreatment technologies) in order to further understand t...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22884
更新日期:2010-12-01 00:00:00
abstract::Synthetic mixtures of predominant lignocellulosic hexose sugars were supplemented with separate aliquots of three inhibitory compounds (furfural, hydroxymethylfurfural (HMF), and acetic acid) in a series of concentrations and fermented by the spent sulfite liquor (SSL)-adapted yeast strain Tembec T1 and the natural is...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20838
更新日期:2006-04-20 00:00:00
abstract::This study examined the hydrodynamic characteristics of a liquid-solid fluidized-bed bioreactor using elastic particles (PVA gel beads) of various diameters as carriers. The drag coefficient-Reynolds number, velocity-voidage, and expansion index-Reynolds number relationships observed during fluidization of PVA gel bea...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10710
更新日期:2003-09-05 00:00:00
abstract::Hydrogen production by Rhodobacter capsulatus is an anaerobic, photobiological process requiring specific mixing conditions. In this study, an innovative design of a photobioreactor is proposed. The design is based on a plate-type photobioreactor with an interconnected meandering channel to allow culture mixing and H2...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.27656
更新日期:2020-12-15 00:00:00
abstract::Pulses of several nonreacting solutes were fed to a column containing immobilized enzyme catalyst beads. The response curves were recorded, and their first and second moments were determined by numerical integration. From the moment analysis, the void volume, internal porosity, and tortuosity of the support were calcu...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260250707
更新日期:1983-07-01 00:00:00
abstract::Numerous biotechnological production processes are based on the submerse cultivation of filamentous fungi. Process design, however, is often hampered by the complex growth pattern of these organisms. In the morphologic development of coagulating filamentous fungi, like Aspergillus niger, conidial aggregation is the fi...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21569
更新日期:2008-02-01 00:00:00
abstract::Microcrystalline cellulose (10 g/L Avicel) was hydrolysed by two major cellulases, cellobiohydrolase I (CBH I) and endoglucanase II (EG II), of Trichoderma reesei. Two types of experiments were performed, and in both cases the enzymes were added alone and together, in equimolar mixtures. In time course studies the rea...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:
更新日期:1998-09-05 00:00:00
abstract::The design and operation of an industrial penicillin-V deacylation reactor is simulated, using a kinetic expression and mass transport parameters for the immobilized enzyme particles which were determined experimentally in a previous study. It is desirable to use a series of equalsized plug flow reactors with pH contr...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260261213
更新日期:1984-12-01 00:00:00
abstract::Acid phosphatase thermal deactivation follows a complex path: an initial decay toward an equilibrium distribution of at least two intermediate structures, mutually at the equilibrium, followed by a final breakdown toward a completely inactive enzyme configuration. The results obtained in the presence of sorbitol have ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260381006
更新日期:1991-12-05 00:00:00
abstract::Fluorescence in situ hybridization (FISH) has been extensively used in the past decades for the detection and localization of microorganisms. However, a mechanistic approach of the whole FISH process is still missing, and the main limiting steps for the hybridization to occur remain unclear. In here, FISH is approache...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章,评审
doi:10.1002/bit.27462
更新日期:2020-10-01 00:00:00
abstract::Feasibility of elemental sulfur reduction by Desulfovibrio desulfuricans in anaerobic conditions in a stirred reactor was studied. Hydrogen was used as energy source, whereas the carbonated species were bicarbonate and yeast extract. Attention was paid to reactor engineering aspects, biofilm formation on the sulfur su...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21457
更新日期:2007-10-15 00:00:00
abstract::The purpose of this article is to provide a few concrete examples of the potential to acceptably reduce the scope of validation and qualification testing based on scientific justification for the specific area of microbial fermentation. The key areas explored include: autoclave operational qualification (OQ) testing, ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.1094
更新日期:2001-07-05 00:00:00
abstract::Formaldehyde is a prevalent environmental toxin and a key intermediate in single carbon metabolism. The ability to monitor formaldehyde concentration is, therefore, of interest for both environmental monitoring and for metabolic engineering of native and synthetic methylotrophs, but current methods suffer from low sen...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26455
更新日期:2018-01-01 00:00:00
abstract::Sugarcane bagasse is an abundant and sustainable resource, generated as a by-product of sugarcane milling. The cellulosic material within bagasse can be broken down into glucose molecules and fermented to produce ethanol, making it a promising feedstock for biofuel production. Mild acid pretreatment hydrolyses the hem...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24984
更新日期:2013-12-01 00:00:00