Abstract:
:Enzymatic acrylation is a process of potentially strong interest to the chemical industry. Direct esterification involving acrylic acid is unfortunately rather slow, with inhibition phenomena appearing at high acid concentrations. In the present study the acrylation of 1-octanol catalyzed by immobilized Candida antarctica lipase B (Novozym 435) was shown to be as much as an order of magnitude faster when ethyl acrylate served as the donor of the acrylic group. Water activity is a key parameter for optimizing the rate of ester synthesis. The optimum water activity for the esterification of octanol by acrylic acid was found to be 0.75, that for its esterification by propionic acid to be 0.45 and the transesterification involving ethyl acrylate to be fastest at a water activity of 0.3. The reasons for these differences in optimum water activity are discussed in terms of enzyme specificity, substrate solvation, and mass transfer effects.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Nordblad M,Adlercreutz Pdoi
10.1002/bit.21706subject
Has Abstractpub_date
2008-04-15 00:00:00pages
1518-24issue
6eissn
0006-3592issn
1097-0290journal_volume
99pub_type
杂志文章abstract::In this article we present magnetic resonance microscopy (MRM) characterization of the advective transport in a biofilm capillary reactor. The biofilm generates non-axial flows that are up to 20% of the maximum axial velocity. The presence of secondary velocities of this magnitude alters the mass transport in the bior...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20400
更新日期:2005-03-30 00:00:00
abstract::Protein glycosylation, or the attachment of sugar moieties (glycans) to proteins, is important for protein stability, activity, and immunogenicity. However, understanding the roles and regulations of site-specific glycosylation events remains a significant challenge due to several technological limitations. These limi...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26502
更新日期:2018-03-01 00:00:00
abstract::Chromatography is the method of choice for the separation of proteins, at both analytical and preparative scale. Orthogonal purification strategies for industrial use can easily be implemented by combining different modes of adsorption. Nevertheless, with flexibility comes the freedom of choice and optimal conditions ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24738
更新日期:2013-03-01 00:00:00
abstract::Current techniques for characterizing biofilm physiology lack the signal filtering capability required for quantifying signals associated with real time biologically active transport. Though a great deal was learned from previous investigations, no results have been reported on the characterization of in vivo, real ti...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22128
更新日期:2009-02-15 00:00:00
abstract::Highly branched mutants of two strains of Aspergillus oryzae (IFO4177, which produces alpha-amylase, and a transformant of IFO4177 [AMG#13], which produces heterologous glucoamylase in addition to alpha-amylase) were generated by UV or nitrous acid mutagenesis. Four mutants of the parental strain (IFO4177), which were...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(sici)1097-0290(19991220)65:6<638::aid-bit
更新日期:1999-12-20 00:00:00
abstract::Application of the well-characterized Streptococcus pyogenes CRISPR-Cas9 system in actinomycetes streptomycetes has enabled high-efficiency multiplex genome editing and CRISPRi-mediated transcriptional regulation in these prolific bioactive metabolite producers. Nonetheless, SpCas9 has its limitations and can be ineff...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.27021
更新日期:2019-09-01 00:00:00
abstract::Numerous studies on poly γ-d-glutamicacid (γ-PGA) production have investigated terrestrial renewable sources for reducing production costs, but there are no studies using waste marine resources so far. We aimed to develop a cost-effective production method of γ-d-PGA by Bacillus sp. SJ-10 using green macroalgae (Ulva ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26966
更新日期:2019-07-01 00:00:00
abstract::A microarray targeting four sequenced strains in the Dehalococcoides (Dhc) genus was used to analyze gene expression in a robust long-term trichloroethene (TCE)-degrading microbial community (designated ANAS) during feeding cycles that involve conditions of periodic substrate supply. The Dhc transcriptome was examined...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24819
更新日期:2013-05-01 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 three-pool growth model of an individual Escherichia coli cell is described herein. The model is based on a previously developed chemically structured complex single cell growth model. The reduction in model complexity and the identification of the essential modes of motion, over the time scale of growth, is achieve...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260310203
更新日期:1988-02-05 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::An efficient method was developed for media separation and cell collection for eukaryotic cells growing in suspension. The method is based on tangential flow microfiltration using an open channel arrangement in a hollow fiber configuration. Best results (highest processing flux rate) for polysulfone hollow fibers were...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260480412
更新日期:1995-11-20 00:00:00
abstract::RNA sequencing (RNASeq) has been widely used to associate alterations in Chinese hamster ovary (CHO) cell gene expression with bioprocess phenotypes; however, alternative messenger RNA (mRNA) splicing, has thus far, received little attention. In this study, we utilized RNASeq for transcriptomic analysis of a monoclona...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.27365
更新日期:2020-08-01 00:00:00
abstract::A mechanistically detailed single-cell model E. coli B/r-A was adapted to simulate the effects of vector presence on cell metabolism. Competition for RNA polymerase between chromosome and plasmid DNA is explicitly included. Distribution of active ribosomes among chromosome- and plasmid-derived messenger RNA, another k...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260290305
更新日期:1987-02-01 00:00:00
abstract::In the present investigation molecular sieve has been found to be a suitable carrier for the immobilization of enzymes. From the present study it may be specifically found that trypsin and pappain can be immobilized by molecular sieve type 4a following a very simple techniqure. The immobilized enzyme can be used both ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260190902
更新日期:1977-09-01 00:00:00
abstract::The heterotrophic marine alga Crypthecodinium cohnii is known to produce docosahexaenoic acid (DHA), a polyunsaturated fatty acid with food and pharmaceutical applications, during batch cultivation on complex media containing sea salt, yeast extract, and glucose. In the present study, fed-batch cultivation was studied...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10513
更新日期:2003-03-20 00:00:00
abstract::Geotrichum candidum was cultivated at the surface of solid model media containing peptone to simulate the composition of Camembert cheese. The surface growth of G. candidum induced the diffusion of substrates from the core to the rind and the diffusion of produced metabolites from the rind to the core. In the range of...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20100
更新日期:2004-07-05 00:00:00
abstract::Propionic acid (PA) and its salts are widely used in the food, pharmaceutical, and chemical industries. Microbial production of PA by propionibacteria is a typical product-inhibited process, and acid resistance is crucial in the improvement of PA titers and productivity. We previously identified two key acid resistanc...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25902
更新日期:2016-06-01 00:00:00
abstract::Phage Φ80 can infect Escherichia coli in a stealthy manner and persist by forming lysogens. Such Φ80 lysogens are fairly common and often go undetected unless the host is grown at temperatures below 37°C. Since low growth temperatures are required for growing temperature-sensitive mutants and often preferred for large...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26971
更新日期:2019-07-01 00:00:00
abstract::In addition to the role of maintaining the pH, buffers can also facilitate the transport of H(+) ions in acid-generating systems. The role of this facilitation in proton transport in porous pellets on acid-generating immobilized enzymic reactions is examined. The activity in these systems can be maximized by a proper ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260270609
更新日期:1985-06-01 00:00:00
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 s...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19970705)55:1<118::AID-BIT
更新日期:1997-07-05 00:00:00
abstract::The effects of dilution rates on the performance of a two-stage fermentation system for a recombinant Escherichia coli culture were studied. Dilution rate determines the apparent or averaged specific growth rate of a heterogeneous population of cells in the recombinant culture. The specific growth rate affects the gen...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260380805
更新日期:1991-10-20 00:00:00
abstract::Fungal morphology in many filamentous fungal fermentations leads to high broth viscosity which limits oxygen mass transfer, and often results in reduced productivity. The objective in this study was to determine if a simple, fed-batch, process strategy-pulsed addition of limiting-carbon source-could be used to reduce ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10548
更新日期:2003-04-05 00:00:00
abstract::A newly designed batch calorimeter was used to investigate the degradability of some celluloses having varying degrees of crystallinity. The PTC of an aerobic culture of Cellulomonas uda ATCC 21399 obtained revealed a diauxic growth which is attributed to the presence of hemicellulose contaminating Avicel and MN300 ce...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260270711
更新日期:1985-07-01 00:00:00
abstract::Biofiltration of air polluted by volatile organic compounds is now recognized by the industrial and research communities as an effective and viable alternative to standard environmental technologies. Whereas many studies have focused on solid/liquid/gas biofilters, there have been fewer reports on waste air treatment ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20035
更新日期:2004-04-05 00:00:00
abstract::A kinetic model describing the cephalosporin biosynthesis in Streptomyces clavuligerus was developed. Using previously reported kinetic data of biosynthetic enzymes, we examined the kinetics of cephalosporin production. The predicted time profile of the specific production rate during a batch culture parallels that of...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260380815
更新日期:1991-10-20 00:00:00
abstract::Galactose oxidase (E.C. 1.1.3.9) was covalently immobilized to chemically modified porous silica particles by reaction of the native enzyme with pendant benzoyl azide groups on the carrier. The enzyme loading on the carrier was 100-150 units per milliliter. The immobilized enzyme was incorporated into a hardware assem...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260181204
更新日期:1976-12-01 00:00:00
abstract::A technology has been developed to achieve optimal attachment of adhesion-independent lymphocytes to microcarrier beads. The activation of T-lymphocytes by concanavalin A was tested under microgravity conditions in an experiment carried out in space during the first Spacelab Life Science Mission. Activation, measure...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260400815
更新日期:1992-10-20 00:00:00
abstract::There is strong evidence in the literature supporting the existence of significant mass transfer limitations on the kinetics of exogenous H(2) consumption by methanogens. The half saturation constant for H (2) uptake by a mixed-culture, CH(4) producing enrichment was measured using an experimental protocol that avoide...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260400704
更新日期:1992-10-05 00:00:00
abstract::Pre-filtration using ion exchange membrane adsorbers can improve parvovirus filter throughput of monoclonal antibodies (mAbs). The membranes work by binding trace foulants, and although some antibody product also binds, yields > or =99% are easily achieved by overloading. Results show that foulant adsorption is depend...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22729
更新日期:2010-07-01 00:00:00