In vivo NMR analysis of the influence of pyruvate decarboxylase and alcohol dehydrogenase of Zymomonas mobilis on the anaerobic metabolism of Escherichia coli

1991 ◽  
Vol 7 (4) ◽  
pp. 305-310 ◽  
Author(s):  
Juan C. Diaz Ricci ◽  
Bernd Hitzmann ◽  
James E. Bailey
Keyword(s):  
Escherichia Coli ◽  
Alcohol Dehydrogenase ◽  
Zymomonas Mobilis ◽  
Anaerobic Metabolism ◽  
Pyruvate Decarboxylase ◽  
Nmr Analysis ◽  
In Vivo Nmr

scholarly journals Ethanologenesis and respiration in a pyruvate decarboxylase-deficient Zymomonas mobilis

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Reinis Rutkis ◽  
Inese Strazdina ◽  
Zane Lasa ◽  
Per Bruheim ◽  
Uldis Kalnenieks
Keyword(s):  
Parent Strain ◽  
Zymomonas Mobilis ◽  
Nadh Oxidase ◽  
Pyruvate Decarboxylase ◽  
Production Ratio ◽  
Pyruvate Node ◽  
Branching Point ◽  
Adh Activity ◽  
Ethanol Synthesis

Abstract Objective Zymomonas mobilis is an alpha-proteobacterium with a rapid ethanologenic pathway, involving Entner–Doudoroff (E–D) glycolysis, pyruvate decarboxylase (Pdc) and two alcohol dehydrogenase (ADH) isoenzymes. Pyruvate is the end-product of the E–D pathway and the substrate for Pdc. Construction and study of Pdc-deficient strains is of key importance for Z. mobilis metabolic engineering, because the pyruvate node represents the central branching point, most novel pathways divert from ethanol synthesis. In the present work, we examined the aerobic metabolism of a strain with partly inactivated Pdc. Results Relative to its parent strain the mutant produced more pyruvate. Yet, it also yielded more acetaldehyde, the product of the Pdc reaction and the substrate for ADH, although the bulk ADH activity was similar in both strains, while the Pdc activity in the mutant was reduced by half. Simulations with the kinetic model of Z. mobilis E-D pathway indicated that, for the observed acetaldehyde to ethanol production ratio in the mutant, the ratio between its respiratory NADH oxidase and ADH activities should be significantly higher, than the measured values. Implications of this finding for the directionality of the ADH isoenzyme operation in vivo and interactions between ADH and Pdc are discussed.

scholarly journals Zymobacter palmae pyruvate decarboxylase is less efficient than that of Zymomonas mobilis for ethanol production in metabolically engineered Synechocystis sp PCC6803

2019 ◽  
Author(s):  
Lorraine Quinn ◽  
Patricia Armshaw ◽  
Tewfik Soulimane ◽  
Con Sheehan ◽  
Michael P Ryan ◽  
...  
Keyword(s):  
Alcohol Dehydrogenase ◽  
Ethanol Production ◽  
Zymomonas Mobilis ◽  
Pyruvate Decarboxylase ◽  
Inducible Promoter ◽  
Control Strain ◽  
Zymobacter Palmae ◽  
Synechocystis Sp ◽  
Pcc 6803

AbstractPyruvate decarboxylase (PDC) from Zymobacter palmae (ZpPDC) has been reported to have a lower Km the Zymomonas mobilis PDC (ZmPDC). ZpPDC was combined with native slr1192 alcohol dehydrogenase (adh) in an attempt to increase ethanol production in the photoautotrophic cyanobacterium Synechocystis sp. PCC 6803 over constructs created with Zmpdc. Native (Zppdc) and codon optimised (ZpOpdc) versions of the ZpPDC were cloned into a construct where the pdc expression was controlled via the psbA2 light inducible promoter from Synechocystis PCC 6803. These constructs were transformed into wildtype Synechocystis PCC 6803. Ethanol levels were then compared with identical constructs containing the Zmpdc. While strains with the Zppdc (UL071) and ZpOpdc (UL072) constructs did produce ethanol, levels were lower compared to a control strain (UL004) expressing the pdc from Zymomonas mobilis. The utilisation of a PDC with a lower Km from Zymobacter palmae did not result in enhanced ethanol production in Synechocystis PCC 6803.

scholarly journals High-resolution structure of the alcohol dehydrogenase domain of the bifunctional bacterial enzyme AdhE

2020 ◽  
Vol 76 (9) ◽  
pp. 414-421
Author(s):  
Liyana Azmi ◽  
Eilis C. Bragginton ◽  
Ian T. Cadby ◽  
Olwyn Byron ◽  
Andrew J. Roe ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Escherichia Coli ◽  
Alcohol Dehydrogenase ◽  
Aldehyde Dehydrogenase ◽  
X Ray ◽  
X Ray Scattering ◽  
Bacterial Enzyme ◽  
High Resolution Structure ◽  
Resolution Structure

The bifunctional alcohol/aldehyde dehydrogenase (AdhE) comprises both an N-terminal aldehyde dehydrogenase (AldDH) and a C-terminal alcohol dehydrogenase (ADH). In vivo, full-length AdhE oligomerizes into long oligomers known as spirosomes. However, structural analysis of AdhE is challenging owing to the heterogeneity of the spirosomes. Therefore, the domains of AdhE are best characterized separately. Here, the structure of ADH from the pathogenic Escherichia coli O157:H7 was determined to 1.65 Å resolution. The dimeric crystal structure was confirmed in solution by small-angle X-ray scattering.

scholarly journals 406 Pyruvate Decarboxylase and Alcohol Dehydrogenase Activities in Sweetpotato under Different Oxygen Atmospheres

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 514A-514
Author(s):  
Yuehe Huang ◽  
David H. Picha ◽  
Anthony W. Kilili
Keyword(s):  
Alcohol Dehydrogenase ◽  
Strong Correlation ◽  
Enzyme Activities ◽  
Ipomoea Batatas ◽  
Alcoholic Fermentation ◽  
Anaerobic Metabolism ◽  
Pyruvate Decarboxylase ◽  
Controlled Atmospheres ◽  
Key Enzyme ◽  
Combined Data

`Beauregard' sweetpotato (Ipomoea batatas L. Lam) roots were maintained under different controlled atmospheres ranging from 0% to 21% O2 at 22 °C in two separate trials for 14 days to study changes in activities of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH). Trial I showed no difference in activities of PDC and ADH between 0% and 1% O2, or among 2%, 5%, and 21% O2. Both PDC and ADH activities were significantly higher at 0% and 1% O2 compared to the 2%, 5%, and 21% O2 atmospheres. In trial II, both enzyme activities were lower at 1.5% O2 than at 0% O2, but higher than at 10% and 21% O2 atmospheres. The combined data of the two trials showed a very strong correlation between PDC and ADH activities (R2 = 0.86). In addition, a strong correlation existed between PDC activity and acetaldehyde concentration (R2 = 0.95). The maximal activities were at pH 6.5 for PDC and at pH 8.5 for ADH in the direction of acetaldehyde-to-ethanol. The results suggest that 1.5% O2 is the critical point for the transition from aerobic to anaerobic metabolism in CA storage of sweetpotato roots, and PDC is the key enzyme in alcoholic fermentation.

scholarly journals Zymobacter palmae Pyruvate Decarboxylase is Less Effective Than That of Zymomonas mobilis for Ethanol Production in Metabolically Engineered Synechocystis sp. PCC6803

2019 ◽  
Vol 7 (11) ◽  
pp. 494 ◽  
Author(s):  
Lorraine Quinn ◽  
Patricia Armshaw ◽  
Tewfik Soulimane ◽  
Con Sheehan ◽  
Michael P. Ryan ◽  
...  
Keyword(s):  
Alcohol Dehydrogenase ◽  
Ethanol Production ◽  
Zymomonas Mobilis ◽  
Pyruvate Decarboxylase ◽  
Biomass Productivity ◽  
Gene Cassette ◽  
Major Effect ◽  
Zymobacter Palmae ◽  
Synechocystis Sp ◽  
Pcc 6803

To produce bioethanol from model cyanobacteria such as Synechocystis, a two gene cassette consisting of genes encoding pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) are required to transform pyruvate first to acetaldehyde and then to ethanol. However the partition of pyruvate to ethanol comes at a cost, a reduction in biomass and pyruvate availability for other metabolic processes. Hence strategies to divert flux to ethanol as a biofuel in Synechocystis are of interest. PDC from Zymobacter palmae (ZpPDC) has been reported to have a lower Km then the Zymomonas mobilis PDC (ZmPDC), which has traditionally been used in metabolic engineering constructs. The Zppdc gene was combined with the native slr1192 alcohol dehydrogenase gene (adhA) in an attempt to increase ethanol production in the photoautotrophic cyanobacterium Synechocystis sp. PCC 6803 over constructs created with the traditional Zmpdc. Native (Zppdc) and codon optimized (ZpOpdc) versions of the ZpPDC were cloned into a construct where pdc expression was controlled via the psbA2 light inducible promoter from Synechocystis sp. PCC 6803. These constructs were transformed into wildtype Synechocystis sp. PCC 6803 for expression and ethanol production. Ethanol levels were then compared with identical constructs containing the Zmpdc. While strains with the Zppdc (UL071) and ZpOpdc (UL072) constructs did produce ethanol, levels were lower compared to a control strain (UL070) expressing the pdc from Zymomonas mobilis. All constructs demonstrated lower biomass productivity illustrating that the flux from pyruvate to ethanol has a major effect on biomass and ultimately overall biofuel productivity. Thus the utilization of a PDC with a lower Km from Zymobacter palmae unusually did not result in enhanced ethanol production in Synechocystis sp. PCC 6803.

scholarly journals Role of Escherichia coli heat shock proteins IbpA and IbpB in protection of alcohol dehydrogenase AdhE against heat inactivation in the presence of oxygen.

2009 ◽  
Vol 56 (1) ◽  
Author(s):  
Ewelina Matuszewska ◽  
Joanna Kwiatkowska ◽  
Elzbieta Ratajczak ◽  
Dorota Kuczyńska-Wiśnik ◽  
Ewa Laskowska
Keyword(s):  
Escherichia Coli ◽  
Heat Stress ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Alcohol Dehydrogenase ◽  
Heat Inactivation ◽  
Prolonged Incubation ◽  
Oxidative Inactivation ◽  
Shock Proteins

Escherichia coli small heat shock proteins IbpA and IbpB are molecular chaperones that bind denatured proteins and facilitate their subsequent refolding by the ATP-dependent chaperones DnaK/DnaJ/GrpE and ClpB. In vivo, the lack of IbpA and IbpB proteins results in increased protein aggregation under severe heat stress or delayed removal of aggregated proteins at recovery temperatures. In this report we followed the appearance and removal of aggregated alcohol dehydrogenase, AdhE, in E. coli submitted to heat stress in the presence of oxygen. During prolonged incubation of cells at 50 degrees C, when AdhE was progressively inactivated, we initially observed aggregation of AdhE and thereafter removal of aggregated AdhE. In contrast to previous studies, the lack of IbpA and IbpB did not influence the formation and removal of AdhE aggregates. However, in DeltaibpAB cells AdhE was inactivated and oxidized faster than in wild type strain. Our results demonstrate that IbpA and IbpB protected AdhE against thermal and oxidative inactivation, providing that the enzyme remained soluble. IbpA and IbpB were dispensable for the processing of irreversibly damaged and aggregated AdhE.

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