Biosynthesis and display of diverse metal nanoparticles by recombinant Escherichia coli

RSC Advances ◽  
2014 ◽  
Vol 4 (102) ◽  
pp. 58717-58719 ◽  
Author(s):  
Yi-Jung Tsai ◽  
Chun-Yu Ouyang ◽  
Shi-Yuan Ma ◽  
Dong-Yu Tsai ◽  
Hsueh-Wei Tseng ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Metal Ions ◽  
Metal Nanoparticles ◽  
Recombinant Escherichia Coli ◽  
E Coli

This study used the recombinant E. coli strain expressing the biomolecule, eumelanin, as an agent for the reduction of metal ions.

scholarly journals Purification and characterization of two fructose diphosphate aldolases from Escherichia coli (Crookes' strain)

1973 ◽  
Vol 131 (4) ◽  
pp. 833-841 ◽  
Author(s):  
Donald Stribling ◽  
Richard N. Perham
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Metal Ions ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Class Ii ◽  
Class I ◽  
E Coli ◽  
Km Value ◽  
Bivalent Metal Ions

Two fructose diphosphate aldolases (EC 4.1.2.13) were detected in extracts of Escherichia coli (Crookes' strain) grown on pyruvate or lactate. The two enzymes can be resolved by chromatography on DEAE-cellulose at pH7.5, or by gel filtration on Sephadex G-200, and both have been obtained in a pure state. One is a typical bacterial aldolase (class II) in that it is strongly inhibited by metal-chelating agents and is reactivated by bivalent metal ions, e.g. Ca2+, Zn2+. It is a dimer with a molecular weight of approx. 70000, and the Km value for fructose diphosphate is about 0.85mm. The other aldolase is not dependent on metal ions for its activity, but is inhibited by reduction with NaBH4 in the presence of substrate. The Km value for fructose diphosphate is about 20μm (although the Lineweaver–Burk plot is not linear) and the enzyme is probably a tetramer with molecular weight approx. 140000. It has been crystallized. On the basis of these properties it is tentatively assigned to class I. The appearance of a class I aldolase in bacteria was unexpected, and its synthesis in E. coli is apparently favoured by conditions of gluconeogenesis. Only aldolase of class II was found in E. coli that had been grown on glucose. The significance of these results for the evolution of fructose diphosphate aldolases is briefly discussed.

In Vivo Synthesis of Diverse Metal Nanoparticles by Recombinant Escherichia coli

2010 ◽  
Vol 49 (39) ◽  
pp. 7019-7024 ◽  
Author(s):  
Tae Jung Park ◽  
Sang Yup Lee ◽  
Nam Su Heo ◽  
Tae Seok Seo
Keyword(s):  
Escherichia Coli ◽  
Metal Nanoparticles ◽  
Recombinant Escherichia Coli ◽  
In Vivo Synthesis

scholarly journals Extracellular expression of Aerococcus viridans pyruvate oxidase in recombinant Escherichia coli through SecB co-expression

RSC Advances ◽  
2019 ◽  
Vol 9 (45) ◽  
pp. 26291-26301 ◽  
Author(s):  
Junwen Lu ◽  
Jianguo Zhang
Keyword(s):  
Escherichia Coli ◽  
Recombinant Escherichia Coli ◽  
Extracellular Expression ◽  
Pyruvate Oxidase ◽  
E Coli ◽  
Aerococcus Viridans ◽  
High Level

Extracellular pyruvate oxidase was expressed at a high level using E. coli by co-expression of chaperone SecB under bla promoter, and therefore cultivation optimization.

scholarly journals Cultivation Conditions for Phytase Production from Recombinant Escherichia coli DH5α

2013 ◽  
Vol 6 ◽  
pp. MBI.S10402 ◽  
Author(s):  
Rafidah Mohd Ariff ◽  
Anwar Fitrianto ◽  
Mohd Yazid Abd. Manap ◽  
Aini Ideris ◽  
Azhar Kassim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Phytase Activity ◽  
Recombinant Escherichia Coli ◽  
Cultivation Conditions ◽  
Phytase Production ◽  
Inoculum Level ◽  
E Coli ◽  
Significant Difference ◽  
Seed Age ◽  
A Cell

Response surface methodology (RSM) was used to optimize the cultivation conditions for the production of phytase by recombinant Escherichia coli DH5α. The optimum predicted cultivation conditions for phytase production were at 3 hours seed age, a 2.5% inoculum level, an L-arabinose concentration of 0.20%, a cell concentration of 0.3 (as measured at 600 nm) and 17 hours post-induction time with a predicted phytase activity of 4194.45 U/mL. The model was validated and the results showed no significant difference between the experimental and the predicted phytase activity ( P = 0.305). Under optimum cultivation conditions, the phytase activity of the recombinant E. coli DH5α was 364 times higher compared to the phytase activity of the wild-type producer, Enterobacter sakazakii ASUIA279. Hence, optimization of the cultivation conditions using RSM positively increased phytase production from recombinant E. coli DH5α.

scholarly journals Construction of Efficient Platform Escherichia coli Strains for Polyhydroxyalkanoate Production by Engineering Branched Pathway

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 509 ◽  
Author(s):  
Hye-Rim Jung ◽  
Su-Yeon Yang ◽  
Yu-Mi Moon ◽  
Tae-Rim Choi ◽  
Hun-Suk Song ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Growth ◽  
Carbon Flux ◽  
Recombinant Escherichia Coli ◽  
Acetyl Coa ◽  
E Coli ◽  
Efficient Conversion ◽  
Pha Production

Polyhydroxyalkanoate (PHA) is a potential substitute for petroleum-based plastics and can be produced by many microorganisms, including recombinant Escherichia coli. For efficient conversion of substrates and maximum PHA production, we performed multiple engineering of branched pathways in E. coli. We deleted four genes (pflb, ldhA, adhE, and fnr), which contributed to the formation of byproducts, using the CRISPR/Cas9 system and overexpressed pntAB, which catalyzes the interconversion of NADH and NADPH. The constructed strain, HR002, showed accumulation of acetyl-CoA and decreased levels of byproducts, resulting in dramatic increases in cell growth and PHA content. Thus, we demonstrated the effects of multiple engineering for redirecting carbon flux into PHA production without any concerns regarding simultaneous deletion.

scholarly journals Optimized Dissolved Oxygen Fuzzy Control for Recombinant Escherichia coli Cultivations

Algorithms ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 326
Author(s):  
Rafael Akira Akisue ◽  
Matheus Lopes Harth ◽  
Antonio Carlos Luperni Horta ◽  
Ruy de Sousa Junior
Keyword(s):  
Escherichia Coli ◽  
Decision Tree ◽  
Dissolved Oxygen ◽  
Fuzzy Inference ◽  
Recombinant Escherichia Coli ◽  
Oxygen Flow ◽  
Oxygen Solubility ◽  
Inference System ◽  
Flow Rates ◽  
E Coli

Due to low oxygen solubility and mechanical stirring limitations of a bioreactor, ensuring an adequate oxygen supply during a recombinant Escherichia coli cultivation is a major challenge in process control. Under the light of this fact, a fuzzy dissolved oxygen controller was developed, taking into account a decision tree algorithm presented in the literature, and implemented in the supervision software SUPERSYS_HCDC. The algorithm was coded in MATLAB with its membership function parameters determined using an Adaptive Network-Based Fuzzy Inference System tool. The controller was composed of three independent fuzzy inference systems: Princ1 and Princ2 assessed whether there would be an increment or a reduction in air and oxygen flow rates (respectively), whilst Delta estimated the size of these variations. To test the controller, simulations with a neural network model and E. coli cultivations were conducted. The fuzzification of the decision tree was successful, resulting in smoothing of air and oxygen flow rates and, hence, in an attenuation of dissolved oxygen oscillations. Statistically, the average standard deviation of the fuzzy controller was 2.45 times lower than the decision tree (9.48%). Results point toward an increase in the flow meter lifespan and a possible reduction of the metabolic stress suffered by E. coli during the cultivation.

scholarly journals Enhanced Production of Carboxymethylcellulase by Recombinant Escherichia coli Strain from Rice Bran with Shifts in Optimal Conditions of Aeration Rate and Agitation Speed on a Pilot-Scale

2019 ◽  
Vol 9 (19) ◽  
pp. 4083
Author(s):  
Chung-Il Park ◽  
Jae-Hong Lee ◽  
Jianhong Li ◽  
Jin-Woo Lee
Keyword(s):  
Escherichia Coli ◽  
Cell Growth ◽  
Pilot Scale ◽  
Aeration Rate ◽  
Coli Strain ◽  
Agitation Speed ◽  
Recombinant Escherichia Coli ◽  
Optimal Conditions ◽  
E Coli ◽  
Enhanced Production

The optimal conditions including the aeration rate and agitation speed of bioreactors for the production of carboxymethylcellulase (CMCase) by a recombinant Escherichia coli KACC 91335P, expressing CMCase gene of B. velezensis A-68, were different from those for its cell growth. The enhanced production of CMCase by E. coli KACC 91335P with the conventional multistage process needs at least two bioreactors. Shifts in the optimal conditions of the aeration rate and agitation speed of the bioreactor from the cell growth of E. coli KACC 91335P to those for its production of CMCase were investigated for development of the simple and economic process with the high productivity and low cost. The production of CMCase by E. coli KACC 91335P with shifts in the optimal conditions of the aeration rate and agitation speed from the cell growth to its production of CMCase in a 100 L pilot-scale bioreactor was 1.36 times higher than that with a fixed optimal conditions of the aeration rate and agitation speed for the production of CMCase and it was even 1.54 times higher than that with a fixed optimal conditions of the aeration rate and agitation speed for cell growth. The best time for the shift in the optimal conditions was found to be the mid-log phase of cell growth. Owing to the mixed-growth-associated production of CMCase by E. coli KACC 91335P, shifts in the optimal conditions of the aeration rate and agitation speed of bioreactors from the cell growth to its production of CMCase seemed to result in relatively more cells for the participation in its production of CMCase, which in turn enhanced its production of CMCase. The process with a simple control for shifts in the aeration rate and agitation speed of a bioreactor for the enhanced production of CMCase by E. coli KACC 91335P on the pilot-scale can be directly applied to the industrial-scaled production of cellulase.

In vitro studies on L-serine deaminase activity of Escherichia coli K12

1980 ◽  
Vol 58 (11) ◽  
pp. 1292-1297 ◽  
Author(s):  
E. B. Newman ◽  
V. Kapoor
Keyword(s):  
Escherichia Coli ◽  
Metal Ions ◽  
In Vitro Studies ◽  
Soluble Enzyme ◽  
E Coli ◽  
Escherichia Coli K12 ◽  
Substrate Analogues ◽  
Mammalian Enzyme ◽  
Serine Deaminase

Extracts of Escherichia coli K12 contain an enzyme which deaminates L-serine. This serine deaminase appears to be a soluble enzyme and is inhibited by substrate analogues, metal ions, and chelators. The activity, which is very unstable in vitro, is protected, and in some cases, even activated by substrate, substrate analogues, and by ferrous ion. The enzyme has proved unstable in all attempts at purification. It resembles closely the L-serine deaminase activity in other microorganisms, but is very different from the mammalian enzyme. As judged by comparison with organisms in which this enzyme serves as part of the principal carbon-handling pathway, L-serine deaminase activity is present in E. coli extracts in physiologically significant amounts.

scholarly journals Highly Sensitive Luminescent Bioassay Using Recombinant Escherichia coli Biosensor for Rapid Detection of Low Cr(VI) Concentration in Environmental Water

Biosensors ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 357
Author(s):  
Guey-Horng Wang ◽  
Chiu-Yu Cheng ◽  
Teh-Hua Tsai ◽  
Pin-Kuan Chiang ◽  
Ying-Chien Chung
Keyword(s):  
Escherichia Coli ◽  
Luminescence Intensity ◽  
Limit Of Detection ◽  
Industrial Effluents ◽  
Coli Strain ◽  
Water Bodies ◽  
Recombinant Escherichia Coli ◽  
Detection Time ◽  
T7 Promoter ◽  
E Coli

In this study, we constructed a recombinant Escherichia coli strain with different promoters inserted between the chromate-sensing regulator chrB and the reporter gene luxAB to sense low hexavalent chromium (Cr(VI)) concentrations (<0.05 mg/L); subsequently, its biosensor characteristics (sensitivity, selectivity, and specificity) for measuring Cr(VI) in various water bodies were evaluated. The luminescence intensity of each biosensor depended on pH, temperature, detection time, coexisting carbon source, coexisting ion, Cr(VI) oxyanion form, Cr(VI) concentration, cell type, and type of medium. Recombinant lux-expressing E. coli with the T7 promoter (T7-lux-E. coli, limit of detection (LOD) = 0.0005 mg/L) had the highest luminescence intensity or was the most sensitive for Cr(VI) detection, followed by E. coli with the T3 promoter (T3-lux-E. coli, LOD = 0.001 mg/L) and that with the SP6 promoter (SP6-lux-E. coli, LOD = 0.005 mg/L). All biosensors could be used to determine whether the Cr(VI) standard was met in terms of water quality, even when using thawing frozen cells as biosensors after 90-day cryogenic storage. The SP6-lux-E. coli biosensor had the shortest detection time (0.5 h) and the highest adaptability to environmental interference. The T7-lux-E. coli biosensor—with the optimal LOD, a wide measurement range (0.0005–0.5 mg/L), and low deviation (−5.0–7.9%) in detecting Cr(VI) from industrial effluents, domestic effluents, and surface water—is an efficient Cr(VI) biosensor. This unprecedented study is to evaluate recombinant lux E. coli with dissimilar promoters for their possible practice in Cr(VI) measurement in water bodies, and the biosensor performance is clearly superior to that of past systems in terms of detection time, LOD, and detection deviation for real water samples.

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