Abstract:
:Based on the recently constructed Escherichia coli itaconic acid production strain ita23, we aimed to improve the productivity by applying a two-stage process strategy with decoupled production of biomass and itaconic acid. We constructed a strain ita32 (MG1655 ΔaceA Δpta ΔpykF ΔpykA pCadCs), which, in contrast to ita23, has an active tricarboxylic acid (TCA) cycle and a fast growth rate of 0.52 hr-1 at 37°C, thus representing an ideal phenotype for the first stage, the growth phase. Subsequently we implemented a synthetic genetic control allowing the downregulation of the TCA cycle and thus the switch from growth to itaconic acid production in the second stage. The promoter of the isocitrate dehydrogenase was replaced by the Lambda promoter (pR ) and its expression was controlled by the temperature-sensitive repressor CI857 which is active at lower temperatures (30°C). With glucose as substrate, the respective strain ita36A grew with a fast growth rate at 37°C and switched to production of itaconic acid at 28°C. To study the impact of the process strategy on productivity, we performed one-stage and two-stage bioreactor cultivations. The two-stage process enabled fast formation of biomass resulting in improved peak productivity of 0.86 g/L/hr (+48%) and volumetric productivity of 0.39 g/L/hr (+22%) in comparison to the one-stage process. With our dynamic production strain, we also resolved the glutamate auxotrophy of ita23 and increased the itaconic acid titer to 47 g/L. The temperature-dependent activation of gene expression by the Lambda promoters (pR /pL ) has been frequently used to improve protein or, in a few cases, metabolite production in two-stage processes. Here we demonstrate that the system can be as well used in the opposite direction to selectively knock-down an essential gene (icd) in E. coli to design a two-stage process for improved volumetric productivity. The control by temperature avoids expensive inducers and has the potential to be generally used to improve cell factory performance.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Harder BJ,Bettenbrock K,Klamt Sdoi
10.1002/bit.26446subject
Has Abstractpub_date
2018-01-01 00:00:00pages
156-164issue
1eissn
0006-3592issn
1097-0290journal_volume
115pub_type
杂志文章abstract::The mobility of water in intact biofilms was measured with pulsed field gradient nuclear magnetic resonance (PFG-NMR) and used to characterise their diffusive properties. The results obtained with several well-defined systems, viz. pure water, agar, and agar containing inert particles or active bacteria were compared ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(sici)1097-0290(19981105)60:3<283::aid-bit
更新日期:1998-11-05 00:00:00
abstract::This article demonstrates the feasibility of a novel process concept for the remediation of PCB contaminated soil. The proposed process consists of PCB extraction from soil using solid polymer beads, followed by biodegradation of the extracted PCBs in a solid-liquid two-phase partitioning bioreactor (TPPB), where PCBs...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21674
更新日期:2008-04-01 00:00:00
abstract::We have studied the growth rate dependence of hepatitis B surface antigen (HBsAg) p24(s) monomer and lipoprotein particle synthesis produced in Saccharomyces cerevisiae using galactose-limited continuous culture. The hepatitis B virus S gene, which encodes the p24(s) monomer, is transcribed under the control of the GA...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19960305)49:5<578::AID-BIT
更新日期:1996-03-05 00:00:00
abstract::Pyruvate production by Torulopsis glabrata was used as a model to study the mechanism of product inhibition and the strategy for enhancing pyruvate production. It was found that the concentration of cell growth and pyruvate deceased with the increase of NaCl and sorbitol concentrations. To enhance the osmotic stress r...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21290
更新日期:2007-07-01 00:00:00
abstract::Biosorption of elements is a little understood phenomenon exhibited by some types of even nonliving microbial biomass. A common fungus Rhizopus arrhizus has been reported to take up uranium from aqueous solutions to the extent of 180 mg U(6+)/g. The mechanism of uranium sequestering by this type of biomass was studied...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260240211
更新日期:1982-02-01 00:00:00
abstract::Understanding the regulatory networks which control specific macrophage phenotypes is essential in identifying novel targets to correct macrophage mediated clinical disorders, often accompanied by inflammatory events. Since mesenchymal stromal cells (MSCs) have been shown to play key roles in regulating immune functio...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25282
更新日期:2014-11-01 00:00:00
abstract::The compound 5-hydroxymethylfurfural (HMF) has attracted much attention due to its versatility as an important bio-based platform chemical. Here, we engineered Raoultella ornithinolytica BF60 as a whole-cell biocatalyst for a highly efficient synthesis of 2,5-furandicarboxylic acid (FDCA) from HMF. Specifically, vario...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26725
更新日期:2018-09-01 00:00:00
abstract::The feasibility of continuous ester synthesis in a membrane bioreactor (MBR) by a recombinant cutinase from Fusarium solani pisi was investigated, using the optimal conditions previously attained by medium engineering. The objective was to analyze the MBR behavior as a differential or an integral reactor. The main com...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/1097-0290(20010120)72:2<127::aid-bit1>3.0.
更新日期:2001-01-20 00:00:00
abstract::Refiner mechanical pulp was biologically treated with several higher fungi in order to test their potential for increasing the strength of paper. It was among the white-rot fungi that the best results were obtained. Polyporus versicolor gave the best overall improvement in handsheet properties with no reduction in tea...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260240913
更新日期:1982-09-01 00:00:00
abstract::We show the design features of a membrane bioreactor based on pulsatile flow across dimpled membranes. Results show an enhanced mass transfer of air of at least five-fold magnitude as compared with flat membranes. An increased working volume form 20 mL to 120 mL reduced the k(L)A at a given Reynolds number because of ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260381016
更新日期:1991-12-05 00:00:00
abstract::Hairy roots have the potential to produce a variety of valuable small and large molecules. The mist reactor is a gas phase bioreactor that has shown promise for low-cost culture of hairy roots. Using a newer, disposable culture bag, mist reactor performance was studied with two species, Artemisia annua L. and Arachis ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22892
更新日期:2010-12-01 00:00:00
abstract::Lipase from Pseudomonas fluorescens biotype I was immobilized by adsorption of anion exchange resin using glutaraldehyde to enhance the adsorption. The activity yield of the immobilized lipase was very low (below 1%) when lipase activity was measured using emulsion substrate. The activity yield was 10-70% when lipase ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260360609
更新日期:1990-09-01 00:00:00
abstract::The production of heterologous proteins by secretion from cellular hosts is an important determinant for the cost of biotherapeutics. A single-cell analytical method called microengraving was used to examine the heterogeneity in secretion by the methylotrophic yeast Pichia pastoris. We show that constitutive secretion...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22688
更新日期:2010-06-01 00:00:00
abstract::We Propose a kinetic expression which accounts for the temperature dependence of ethanol yield losses in batch alcoholic fermentation. Moreover, the characteristic parameters of the microbial growth equation have been calculated for Saccharomyces cerevisiae under typical wine industry conditions. A substrate consumpti...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260380708
更新日期:1991-10-05 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::The feasibility of anaerobic methanethiol (MT) degradation at elevated sodium concentrations was investigated in a mesophilic (30 degrees C) lab-scale upflow anaerobic sludge bed (UASB) reactor, inoculated with estuarine sediment originating from the Wadden Sea (The Netherlands). MT was almost completely degraded (>95...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21367
更新日期:2007-09-01 00:00:00
abstract::Recent studies have demonstrated the feasibility of using ultrafiltration for the purification of plasmid DNA, but there is still little understanding of the factors governing DNA transmission. Experimental data were obtained for the transmission of a 3.0 kbp supercoiled plasmid DNA through composite regenerated cellu...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21575
更新日期:2008-02-01 00:00:00
abstract::A modified mixing plane approach for steady state simulation of flow field in fully baffled biological reactor is presented and discussed. Without requiring any experimental input, this approach of dividing the vessel into suitable number of connected and disconnected zones; solving steady state equation separately in...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21030
更新日期:2006-11-05 00:00:00
abstract::Hydroxycinnamic acids are known to inhibit microbial growth during fermentation of lignocellulosic biomass hydrolysates, and the ability to diminish hydroxycinnamic acid toxicity would allow for more effective biological conversion of biomass to fuels and other value-added products. In this work, we provide a proof-of...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25473
更新日期:2015-03-01 00:00:00
abstract::Working conditions of a biochemical fuel cell formed by an oxygen cathode and a platinum bioanode in a Saccharomyces cerevisiae suspension metabolizing glucose are described. The biocell response in terms of bioanode potential and current drainage under different fermentation conditions is reported. A kinetic equation...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260171011
更新日期:1975-10-01 00:00:00
abstract::This research focused on how the extent and type of primary solid-liquid separation can affect the performance of guard filtration and chromatography, in this instance hydrophobic interaction chromatography. The system used in the study was yeast (Saccharomyces cerevisiae) with the target molecule being an intracellul...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21823
更新日期:2008-08-01 00:00:00
abstract::Bacterial profile modification (BPM), a form of tertiary oil recovery, diverts water from the water-flooded high-permeability zone into the oil-bearing low-permeability zone. During field use, exopolymer-producing bacteria plug the high-permeability zone only in the immediate vicinity of the injection point (the near-...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20315
更新日期:2005-01-05 00:00:00
abstract::An alkali stable polyamidase was isolated from a new strain of Nocardia farcinica. The enzyme consists of four subunits with a total molecular weight of 190 kDa. The polyamidase cleaved amide and ester bonds of water insoluble model substrates like adipic acid bishexylamide and bis(benzoyloxyethyl)terephthalate and hy...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22139
更新日期:2009-03-01 00:00:00
abstract::A two-parameter deactivation model is proposed to describe the kinetics of activity stabilization for some enzymes. The single-step unimolecular mechanism exhibits non-first-order deactivation kinetics since the final enzyme state, E(1) is not completely inactivated. The usefulness of the model is demonstrated by appl...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260300604
更新日期:1987-10-20 00:00:00
abstract::Mevalonate is a useful metabolite synthesized from three molecules of acetyl-CoA, consuming two molecules of NADPH. Escherichia coli ( E. coli) catabolizes glucose to acetyl-CoA via several routes, such as the Embden-Meyerhof-Parnas (EMP) and the oxidative pentose phosphate (oxPP) pathways. Although the oxPP pathway s...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26923
更新日期:2019-05-01 00:00:00
abstract::Stem cell self-renewal versus differentiation fate decisions are difficult to characterize and analyze due to multiple competing rate processes occurring simultaneously among heterogeneous cell subpopulations. To address this challenge, we describe a mathematical model for cell population dynamics that allows flow cyt...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20244
更新日期:2004-11-05 00:00:00
abstract::In vitro gliding assay, microtubule translocation by kinesin motor proteins on a surface, has been used as an engineering tool in analyte detection, molecular cargo transport, and other applications. Although controlling the moving direction is often necessary to realize these applications, current direction control m...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26933
更新日期:2019-05-01 00:00:00
abstract::Saccharomyces cerevisiae is a widely used host organism for the production of heterologous proteins, often cultivated in glucose-based fed-batch processes. This production system however has many factors limiting the productivity, mainly towards the end of the fermentation. For the optimised production of a Camelid an...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21150
更新日期:2007-02-15 00:00:00
abstract::The key to achieving successful, reproducible results following the introduction of beneficial microbes into soil relies on the survival rate of the inoculated bacteria in a heterogeneous soil environment and hence an improved encapsulation method was developed. Owing to the constraints associated with the inoculum fo...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20957
更新日期:2006-09-05 00:00:00
abstract::A dynamic method is proposed for k(l)a measurement in aerated and agitated reactors, in which a change in the total pressure in the reactor by approximately 20% leads to a simultaneous change in the oxygen concentration in all the bubbles in the dispersion. This procedure suppresses the influence of nonideal mixing of...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260331107
更新日期:1989-05-01 00:00:00