1
|
Vanyan L, Trchounian K. Glucose concentration is determinant for the functioning of hydrogenase 1 and hydrogenase 2 in regulating the proton and potassium fluxes in Escherichia coli at pH 7.5. Biochimie 2024:S0300-9084(24)00172-X. [PMID: 39038731 DOI: 10.1016/j.biochi.2024.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 07/17/2024] [Accepted: 07/19/2024] [Indexed: 07/24/2024]
Abstract
This study examines how FOF1-ATPase, hydrogenases (Hyd-1 and Hyd-2), and potassium transport systems (TrkA) interact to maintain the proton motive force (pmf) in E. coli during fermentation of different glucose concentrations (2 g L-1 and 8 g L-1). Our findings indicate that mutants lacking the hyaA-hyaC genes exhibited a 30 % increase in total proton flux compared to the wild type when grown with 2 g L-1 glucose. This has been observed during assays where similar glucose levels were supplemented. Disruptions in proton pumping, particularly in hyaB and hyaC single mutants, led to increased potassium uptake. The hyaB mutant showed a threefold increase in the contribution of FOF1-ATPase to proton flux, suggesting a significant role for Hyd-1 in proton translocation. In the hybC mutant grown in 2 g L-1 glucose conditions, DCCD-sensitive fluxes decreased by 70 %, indicating critical role of Hyd-2 in proton transport and FOF1 function. When cells were grown with 8 g L-1 glucose, the 2H+/1K+ ratio was significantly disturbed in both wild type and mutants. Despite these perturbances, mutants with disruptions in Hyd-1 and Hyd-2 maintained constant FOF1 function, suggesting that this enzyme remains stable in glucose-rich environments. These results provide valuable insights into how Hyd-1 and Hyd-2 contribute to the regulation of ion transport, particularly proton translocation, in response to glucose concentration. Our study uncovered potential complementary mechanisms between Hyd-1 and Hyd-2 subunits, suggesting a complex interplay between these enzymes via metabolic cross talk with FOF1 in response to glucose concentrations to maintain pmf.
Collapse
Affiliation(s)
- Liana Vanyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia; Research Institute of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia; Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia
| | - Karen Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia; Research Institute of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia; Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia.
| |
Collapse
|
2
|
Babayan A, Vassilian A, Poladyan A, Trchounian K. Role of the Escherichia coli FocA and FocB formate channels in controlling proton/potassium fluxes and hydrogen production during osmotic stress in energy-limited, stationary phase fermenting cells. Biochimie 2024; 221:91-98. [PMID: 38307245 DOI: 10.1016/j.biochi.2024.01.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/12/2024] [Accepted: 01/30/2024] [Indexed: 02/04/2024]
Abstract
Escherichia coli FocA and FocB formate channels export formate or import it for further disproportionation by the formate hydrogenlyase (FHL) complex to H2 and CO2. Here, we show that under pH and osmotic stress FocA and FocB play important roles in regulating proton and potassium fluxes and couple this with H2 production in stationary-phase cells. Using whole-cell assays with glucose as electron donor, a focB mutant showed a 50 % decrease in VH2, while N'N'-dicyclohexylcarbodiimide (DCCD) treatment of osmotically stressed cells underlined the role of FOF1 ATPase in H2 production. At pH 7.5 and under osmotic stress FocB contributed to the proton flux but not to the potassium flux. At pH 5.5 both formate channels contributed to the proton and potassium fluxes. Particulalry, a focA mutant had 40 % lower potassium flux whereas the proton flux increased approximately two-fold. Moreover, at pH 5.5H2 production was totally inhibited by DCCD in the focA mutant. Taken together, our results suggest that depending on external pH, the formate channels play an important role in osmoregulation by helping to balance proton/potassium fluxes and H2 production, and thus assist the proton FOF1-ATPase in maintenance of ion gradients in fermenting stationary-phase cells.
Collapse
Affiliation(s)
- A Babayan
- Department of Biochemistry, Microbiology and Biotechnology, Yerevan State University, 0025, Yerevan, Armenia; Research Institute of Biology, Yerevan State University, 0025, Yerevan, Armenia
| | - A Vassilian
- Research Institute of Biology, Yerevan State University, 0025, Yerevan, Armenia.
| | - A Poladyan
- Department of Biochemistry, Microbiology and Biotechnology, Yerevan State University, 0025, Yerevan, Armenia; Research Institute of Biology, Yerevan State University, 0025, Yerevan, Armenia.
| | - K Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Yerevan State University, 0025, Yerevan, Armenia; Research Institute of Biology, Yerevan State University, 0025, Yerevan, Armenia; Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 0025, Yerevan, Armenia.
| |
Collapse
|
3
|
Gevorgyan H, Poladyan A, Trchounian K, Vassilian A. Proton conductance and regulation of proton/potassium fluxes in Escherichia coli FhlA-lacking cells during fermentation of mixed carbon sources. Arch Biochem Biophys 2024; 755:109999. [PMID: 38621444 DOI: 10.1016/j.abb.2024.109999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/25/2024] [Accepted: 04/12/2024] [Indexed: 04/17/2024]
Abstract
Escherichia coli uptake potassium ions with the coupling of proton efflux and energy utilization via proton FOF1-ATPase. In this study contribution of formate hydrogen lyase (FHL) complexes in the proton/potassium fluxes and the formation of proton conductance (CMH+) were investigated using fhlA mutant strain. The proton flux rate (JH+) decreased in fhlA by ∼ 25 % and ∼70 % during the utilization of glucose and glycerol, respectively, at 20 h suggesting H+ transport via or through FHL complexes. The decrease in JK+ in fhlA by ∼40 % proposed the interaction between FHL and Trk secondary transport system during mixed carbon fermentation. Moreover, the usage of N,N'-dicyclohexylcarbodiimide (DCCD) demonstrated the mediation of FOF1-ATPase in this interaction. CMH+ was 13.4 nmol min-1 mV-1 in WT at 20 h, which decreased by 20 % in fhlA. Taken together, FHL complexes have a significant contribution to the modulation of H+/K+ fluxes and the CMH + for efficient energy transduction and regulation of the proton motive force during mixed carbon sources fermentation.
Collapse
Affiliation(s)
- Heghine Gevorgyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 0025, Yerevan, Armenia; Research Institute of Biology, Faculty of Biology, Yerevan State University, 0025, Yerevan, Armenia; Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 0025, Yerevan, Armenia
| | - Anna Poladyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 0025, Yerevan, Armenia; Research Institute of Biology, Faculty of Biology, Yerevan State University, 0025, Yerevan, Armenia.
| | - Karen Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 0025, Yerevan, Armenia; Research Institute of Biology, Faculty of Biology, Yerevan State University, 0025, Yerevan, Armenia; Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 0025, Yerevan, Armenia.
| | - Anait Vassilian
- Research Institute of Biology, Faculty of Biology, Yerevan State University, 0025, Yerevan, Armenia
| |
Collapse
|
4
|
Gevorgyan H, Baghdasaryan L, Trchounian K. Regulation of metabolism and proton motive force generation during mixed carbon fermentation by an Escherichia coli strain lacking the F OF 1-ATPase. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2024; 1865:149034. [PMID: 38354879 DOI: 10.1016/j.bbabio.2024.149034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 01/15/2024] [Accepted: 02/09/2024] [Indexed: 02/16/2024]
Abstract
Proton FOF1-ATPase is the key enzyme in E. coli under fermentative conditions. In this study the role of E. coli proton ATPase in the μ and formation of metabolic pathways during the fermentation of mixture of glucose, glycerol and formate using the DK8 (lacking FOF1) mutant strain was investigated. It was shown that the contribution of FOF1-ATPase in the specific growth rate was ∼45 %. Formate was not taken up in the DK8 strain during the initial hours of the growth. The utilization rates of glucose and glycerol were unchanged in DK8, however, the production of succinate, lactate and ethanol was decreased causing a reduction of the redox state up to -450 mV. Moreover, the contribution of FOF1-ATPase in the interplay between H+ and H2 cycles was described depending on the bacterial growth phase and main utilizing substrate. Besides, the H2 production rate in the DK8 strain was decreased by ∼60 % at 20 h and was absent at 72 h. Δp was decreased from -157 ± 4.8 mV to -140 ± 4.2 mV at 20 h and from -195 ± 5.9 mV to -148 ± 4.4 mV at 72 h, compared to WT. Taken together it can be concluded that during fermentation of mixed carbon sources metabolic cross talk between FOF1-ATPase-TrkA-Hyd-Fdh-H is taking place for maintaining the cell energy balance via regulation proton motive force.
Collapse
Affiliation(s)
- Heghine Gevorgyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 0025 Yerevan, Armenia; Scientific-Research Institute of Biology, Faculty of Biology, Yerevan State University, 0025 Yerevan, Armenia; Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 0025 Yerevan, Armenia
| | - Lilit Baghdasaryan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 0025 Yerevan, Armenia; Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 0025 Yerevan, Armenia
| | - Karen Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 0025 Yerevan, Armenia; Scientific-Research Institute of Biology, Faculty of Biology, Yerevan State University, 0025 Yerevan, Armenia; Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 0025 Yerevan, Armenia.
| |
Collapse
|
5
|
Gevorgyan H, Abaghyan T, Mirumyan M, Yenkoyan K, Trchounian K. Propionic and valproic acids have an impact on bacteria viability, proton flux and ATPase activity. J Bioenerg Biomembr 2023; 55:397-408. [PMID: 37700074 DOI: 10.1007/s10863-023-09983-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 08/29/2023] [Indexed: 09/14/2023]
Abstract
Short-chain fatty acids like propionic (PPA) and valproic acids (VP) can alter gut microbiota, which is suggested to play a role in development of autism spectrum disorders (ASD). In this study we investigated the role of various concentrations of PPA and VP in gut enteric gram-negative Escherichia coli K12 and gram-positive Enterococcus hirae ATCC 9790 bacteria growth properties, ATPase activity and proton flux. The specific growth rate (µ) was 0.24 h-1 and 0.82 h-1 in E. coli and E. hirae, respectively. Different concentrations of PPA reduced the value of µ similarly in both strains. PPA affects membrane permeability only in E. hirae. PPA decreased DCCD-sensitive ATPase activity in the presence of K+ ions by 20% in E. coli and 40% in E. hirae suggesting the importance of the FOF1-K+ transport system in the regulation of PPA-disrupted homeostasis. Moreover, the H+ flux during PPA consumption could be the protective mechanism for enteric bacteria. VP has a selective effect on the µ depending on bacteria. The overwhelming effect of VP was detected on the K+-promoted ATPase activity in E. hirae. Taken together it can be suggested that PPA and VP have a disruptive effect on E. coli and E. hirae growth, viability, bioenergetic and biochemical properties, which are connected with the alteration of FOF1-ATPase activity and H+ flux rate or direction.
Collapse
Affiliation(s)
- Heghine Gevorgyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian Str, Yerevan, 0025, Armenia
- Scientific-Research Institute of Biology, Faculty of Biology, Yerevan State University, Yerevan, 0025, Armenia
- Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, Yerevan, 0025, Armenia
| | - Tamara Abaghyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian Str, Yerevan, 0025, Armenia
- Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, Yerevan, 0025, Armenia
- Neuroscience Laboratory, Cobrain Center, Yerevan State Medical University named after M. Heratsi, Yerevan, 0025, Armenia
| | - Margarita Mirumyan
- Neuroscience Laboratory, Cobrain Center, Yerevan State Medical University named after M. Heratsi, Yerevan, 0025, Armenia
- Department of Biochemistry, Yerevan State Medical University named after M. Heratsi, Yerevan, 0025, Armenia
| | - Konstantin Yenkoyan
- Neuroscience Laboratory, Cobrain Center, Yerevan State Medical University named after M. Heratsi, Yerevan, 0025, Armenia.
- Department of Biochemistry, Yerevan State Medical University named after M. Heratsi, Yerevan, 0025, Armenia.
| | - Karen Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian Str, Yerevan, 0025, Armenia.
- Scientific-Research Institute of Biology, Faculty of Biology, Yerevan State University, Yerevan, 0025, Armenia.
- Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, Yerevan, 0025, Armenia.
| |
Collapse
|
6
|
Kalathil S, Miller M, Reisner E. Microbial Fermentation of Polyethylene Terephthalate (PET) Plastic Waste for the Production of Chemicals or Electricity. Angew Chem Int Ed Engl 2022; 61:e202211057. [PMID: 36103351 PMCID: PMC9828132 DOI: 10.1002/anie.202211057] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Indexed: 01/12/2023]
Abstract
Ideonella sakaiensis (I. sakaiensis) can grow on polyethylene terephthalate (PET) as the major carbon and energy source. Previous work has shown that PET conversion in the presence of oxygen released carbon dioxide and water while yielding adenosine triphosphate (ATP) through oxidative phosphorylation. This study demonstrates that I. sakaiensis is a facultative anaerobe that ferments PET to the feedstock chemicals acetate and ethanol in the absence of oxygen. In addition to PET, the pure monomer ethylene glycol (EG), the intermediate product ethanol, and the carbohydrate fermentation test substance maltose can also serve as fermenting substrates. Co-culturing of I. sakaiensis with the electrogenic and acetate-consuming Geobacter sulfurreducens produced electricity from PET or EG. This newly identified plastic fermentation process by I. sakaiensis provides thus a novel biosynthetic route to produce high-value chemicals or electricity from plastic waste streams.
Collapse
Affiliation(s)
- Shafeer Kalathil
- Yusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeCB2 1EWUK
| | - Melanie Miller
- Yusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeCB2 1EWUK
| | - Erwin Reisner
- Yusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeCB2 1EWUK
| |
Collapse
|
7
|
Karapetyan L, Mikoyan G, Vassilian A, Valle A, Bolivar J, Trchounian A, Trchounian K. Escherichia coli Dcu C 4-dicarboxylate transporters dependent proton and potassium fluxes and F OF 1-ATPase activity during glucose fermentation at pH 7.5. Bioelectrochemistry 2021; 141:107867. [PMID: 34118553 DOI: 10.1016/j.bioelechem.2021.107867] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/24/2021] [Accepted: 05/28/2021] [Indexed: 11/27/2022]
Abstract
During fermentation in Escherichia coli succinate is transported via Dcu transporters, encoded dcuA, dcuB, dcuC and dcuD although the role of DcuD protein has not been elucidated yet. It has been shown contribution of Dcu transporters in the N,N'-dicyclohexylcarbodiimide (DCCD) sensitive proton and potassium transport through the cytoplasmic membrane and membrane-associated ATPase activity. Total H± efflux was decreased ~ 40% while K± uptake was absent in dcuD mutant. DCCD-sensitive H± flux was absent in dcuD nevertheless it was increased ~ 3 fold in dcuACB. K± uptake in dcuACB was stimulated ~ 30% compared to wild type but in DCCD assays K± ions were effluxed with the rate of 0.15 mmol/min per 109 cells/ml. In dcuACB mutant membrane potential (ΔΨ) was ~ 30 mV higher than in wild type. dcuD gene expression was increased in the dcuACB mutant respect to wild type at pH 7.5 (~120%), suggesting that an increment of DcuD activity compensates the lack of DcuA, DcuC and DcuB carriers. It can be concluded that active DcuD is important for H± efflux via the FOF1-ATPase and K± uptake at pH 7.5. In addition, DcuA, DcuB and DcuC transporters are crucial for regulating DCCD-sensitive K± transport and ΔΨ in E. coli.
Collapse
Affiliation(s)
- L Karapetyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian str., 0025 Yerevan, Armenia; Scientific-Research Institute of Biology, Yerevan State University, 1 A. Manoogian str., 0025 Yerevan, Armenia; Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 1 A. Manoogian str., 0025 Yerevan, Armenia
| | - G Mikoyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian str., 0025 Yerevan, Armenia; Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 1 A. Manoogian str., 0025 Yerevan, Armenia
| | - A Vassilian
- Scientific-Research Institute of Biology, Yerevan State University, 1 A. Manoogian str., 0025 Yerevan, Armenia
| | - A Valle
- Department of Biomedicine, Biotechnology and Public Health-Biochemistry and Molecular Biology, University of Cádiz, Avda. República Saharui s/n, 11510 Puerto Real, Cádiz, Spain
| | - J Bolivar
- Department of Biomedicine, Biotechnology and Public Health-Biochemistry and Molecular Biology, University of Cádiz, Avda. República Saharui s/n, 11510 Puerto Real, Cádiz, Spain
| | - A Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian str., 0025 Yerevan, Armenia; Scientific-Research Institute of Biology, Yerevan State University, 1 A. Manoogian str., 0025 Yerevan, Armenia
| | - K Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian str., 0025 Yerevan, Armenia; Scientific-Research Institute of Biology, Yerevan State University, 1 A. Manoogian str., 0025 Yerevan, Armenia; Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 1 A. Manoogian str., 0025 Yerevan, Armenia.
| |
Collapse
|
8
|
Gevorgyan H, Khalatyan S, Vassilian A, Trchounian K. The role of Escherichia coli FhlA transcriptional activator in generation of proton motive force and F O F 1 -ATPase activity at pH 7.5. IUBMB Life 2021; 73:883-892. [PMID: 33773019 DOI: 10.1002/iub.2470] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 03/08/2021] [Accepted: 03/19/2021] [Indexed: 12/29/2022]
Abstract
Escherichia coli is able to utilize the mixture of carbon sources and produce molecular hydrogen (H2 ) via formate hydrogen lyase (FHL) complexes. In current work role of transcriptional activator of formate regulon FhlA in generation of fermentation end products and proton motive force, N'N'-dicyclohexylcarbodiimide (DCCD)-sensitive ATPase activity at 20 and 72 hr growth during utilization of mixture of glucose, glycerol, and formate were investigated. It was shown that in fhlA mutant specific growth rate was ~1.5 fold lower compared to wt, while addition of DCCD abolished the growth in fhlA but not in wt. Formate was not utilized in fhlA mutant but wt cells simultaneously utilized formate with glucose. Glycerol utilization started earlier (from 2 hr) in fhlA than in wt. The DCCD-sensitive ATPase activity in wt cells membrane vesicles increased ~2 fold at 72 hr and was decreased 70% in fhlA. Addition of formate in the assays increased proton ATPase activity in wt and mutant strain. FhlA absence mainly affected the ΔpH but not ΔΨ component of Δp in the cells grown at 72 hr but not in 24 hr. The Δp in wt cells decreased from 24 to 72 hr of growth ~40 mV while in fhlA mutant it was stable. Taken together, it is suggested that FhlA regulates the concentration of fermentation end products and via influencing FO F1 -ATPase activity contributes to the proton motive force generation.
Collapse
Affiliation(s)
- Heghine Gevorgyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, Yerevan, Armenia.,Faculty of Biology, Scientific-Research Institute of Biology, Yerevan State University, Yerevan, Armenia.,Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, Yerevan, Armenia
| | - Satenik Khalatyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, Yerevan, Armenia.,Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, Yerevan, Armenia.,Laboratory of Neuroscience, Yerevan State Medical University, Yerevan, Armenia
| | - Anait Vassilian
- Department of Ecology and Nature Protection, Faculty of Biology, Yerevan State University, Yerevan, Armenia
| | - Karen Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, Yerevan, Armenia.,Faculty of Biology, Scientific-Research Institute of Biology, Yerevan State University, Yerevan, Armenia.,Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, Yerevan, Armenia
| |
Collapse
|
9
|
Mikoyan G, Karapetyan L, Vassilian A, Trchounian A, Trchounian K. External succinate and potassium ions influence Dcu dependent FOF1-ATPase activity and H+ flux of Escherichia coli at different pHs. J Bioenerg Biomembr 2020; 52:377-382. [DOI: 10.1007/s10863-020-09847-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/19/2020] [Indexed: 01/12/2023]
|
10
|
Susceptibility of the Formate Hydrogenlyase Reaction to the Protonophore CCCP Depends on the Total Hydrogenase Composition. INORGANICS 2020. [DOI: 10.3390/inorganics8060038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Fermentative hydrogen production by enterobacteria derives from the activity of the formate hydrogenlyase (FHL) complex, which couples formate oxidation to H2 production. The molybdenum-containing formate dehydrogenase and type-4 [NiFe]-hydrogenase together with three iron-sulfur proteins form the soluble domain, which is attached to the membrane by two integral membrane subunits. The FHL complex is phylogenetically related to respiratory complex I, and it is suspected that it has a role in energy conservation similar to the proton-pumping activity of complex I. We monitored the H2-producing activity of FHL in the presence of different concentrations of the protonophore CCCP. We found an inhibition with an apparent EC50 of 31 µM CCCP in the presence of glucose, a higher tolerance towards CCCP when only the oxidizing hydrogenase Hyd-1 was present, but a higher sensitivity when only Hyd-2 was present. The presence of 200 mM monovalent cations reduced the FHL activity by more than 20%. The Na+/H+ antiporter inhibitor 5-(N-ethyl-N-isopropyl)-amiloride (EIPA) combined with CCCP completely inhibited H2 production. These results indicate a coupling not only between Na+ transport activity and H2 production activity, but also between the FHL reaction, proton import and cation export.
Collapse
|
11
|
Petrosyan H, Vanyan L, Mirzoyan S, Trchounian A, Trchounian K. Roasted coffee wastes as a substrate for Escherichia coli to grow and produce hydrogen. FEMS Microbiol Lett 2020; 367:5848194. [DOI: 10.1093/femsle/fnaa088] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 05/27/2020] [Indexed: 12/25/2022] Open
Abstract
ABSTRACT
After brewing roasted coffee, spent coffee grounds (SCGs) are generated being one of the daily wastes emerging in dominant countries with high rate and big quantity. Escherichia coli BW25113 wild-type strain, mutants with defects in hydrogen (H2)-producing/oxidizing four hydrogenases (Hyd) (ΔhyaB ΔhybC, ΔhycE, ΔhyfG) and septuple mutant (ΔhyaB ΔhybC ΔhycA ΔfdoG ΔldhA ΔfrdC ΔaceE) were investigated by measuring change of external pH, bacterial growth and H2 production during the utilization of SCG hydrolysate. In wild type, H2 was produced with rate of 1.28 mL H2 (g sugar)−1 h−1 yielding 30.7 mL H2 (g sugar)−1 or 2.75 L (kg SCG)−1 during 24 h. In septuple mutant, H2 production yield was 72 mL H2 (g sugar)−1 with rate of 3 mL H2 (g sugar)−1 h−1. H2 generation was absent in hycE single mutant showing the main role of Hyd-3 in H2 production. During utilization of SCG wild type, specific growth rate was 0.72 ± 0.01 h−1 with biomass yield of 0.3 g L−1. Genetic modifications and control of external parameters during growth could lead to prolonged and enhanced microbiological H2 production by organic wastes, which will aid more efficiently global sustainable energy needs resulting in diversification of mobile and fixed energy sources.
Collapse
Affiliation(s)
- Hripsime Petrosyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 Alex Manoogian Str., 0025 Yerevan, Armenia
- Scientific Research Institute of Biology, Faculty of Biology, Yerevan State University, 0025 Yerevan, Armenia
- Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 0025 Yerevan, Armenia
| | - Liana Vanyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 Alex Manoogian Str., 0025 Yerevan, Armenia
- Scientific Research Institute of Biology, Faculty of Biology, Yerevan State University, 0025 Yerevan, Armenia
- Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 0025 Yerevan, Armenia
| | - Satenik Mirzoyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 Alex Manoogian Str., 0025 Yerevan, Armenia
- Scientific Research Institute of Biology, Faculty of Biology, Yerevan State University, 0025 Yerevan, Armenia
- Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 0025 Yerevan, Armenia
| | - Armen Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 Alex Manoogian Str., 0025 Yerevan, Armenia
- Scientific Research Institute of Biology, Faculty of Biology, Yerevan State University, 0025 Yerevan, Armenia
| | - Karen Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 Alex Manoogian Str., 0025 Yerevan, Armenia
- Scientific Research Institute of Biology, Faculty of Biology, Yerevan State University, 0025 Yerevan, Armenia
- Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 0025 Yerevan, Armenia
| |
Collapse
|
12
|
Benoit SL, Maier RJ, Sawers RG, Greening C. Molecular Hydrogen Metabolism: a Widespread Trait of Pathogenic Bacteria and Protists. Microbiol Mol Biol Rev 2020; 84:e00092-19. [PMID: 31996394 PMCID: PMC7167206 DOI: 10.1128/mmbr.00092-19] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Pathogenic microorganisms use various mechanisms to conserve energy in host tissues and environmental reservoirs. One widespread but often overlooked means of energy conservation is through the consumption or production of molecular hydrogen (H2). Here, we comprehensively review the distribution, biochemistry, and physiology of H2 metabolism in pathogens. Over 200 pathogens and pathobionts carry genes for hydrogenases, the enzymes responsible for H2 oxidation and/or production. Furthermore, at least 46 of these species have been experimentally shown to consume or produce H2 Several major human pathogens use the large amounts of H2 produced by colonic microbiota as an energy source for aerobic or anaerobic respiration. This process has been shown to be critical for growth and virulence of the gastrointestinal bacteria Salmonella enterica serovar Typhimurium, Campylobacter jejuni, Campylobacter concisus, and Helicobacter pylori (including carcinogenic strains). H2 oxidation is generally a facultative trait controlled by central regulators in response to energy and oxidant availability. Other bacterial and protist pathogens produce H2 as a diffusible end product of fermentation processes. These include facultative anaerobes such as Escherichia coli, S Typhimurium, and Giardia intestinalis, which persist by fermentation when limited for respiratory electron acceptors, as well as obligate anaerobes, such as Clostridium perfringens, Clostridioides difficile, and Trichomonas vaginalis, that produce large amounts of H2 during growth. Overall, there is a rich literature on hydrogenases in growth, survival, and virulence in some pathogens. However, we lack a detailed understanding of H2 metabolism in most pathogens, especially obligately anaerobic bacteria, as well as a holistic understanding of gastrointestinal H2 transactions overall. Based on these findings, we also evaluate H2 metabolism as a possible target for drug development or other therapies.
Collapse
Affiliation(s)
- Stéphane L Benoit
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - Robert J Maier
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - R Gary Sawers
- Institute of Microbiology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Chris Greening
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
- Department of Microbiology, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia
| |
Collapse
|
13
|
Jain S, Dietrich HM, Müller V, Basen M. Formate Is Required for Growth of the Thermophilic Acetogenic Bacterium Thermoanaerobacter kivui Lacking Hydrogen-Dependent Carbon Dioxide Reductase (HDCR). Front Microbiol 2020; 11:59. [PMID: 32082286 PMCID: PMC7005907 DOI: 10.3389/fmicb.2020.00059] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 01/13/2020] [Indexed: 12/17/2022] Open
Abstract
The hydrogen-dependent carbon dioxide reductase is a soluble enzyme complex that directly utilizes hydrogen (H2) for the reduction of carbon dioxide (CO2) to formate in the first step of the acetyl-coenzyme A- or Wood-Ljungdahl pathway (WLP). HDCR consists of 2 catalytic subunits, a hydrogenase and a formate dehydrogenase (FDH) and two small subunits carrying iron-sulfur clusters. The enzyme complex has been purified and characterized from two acetogenic bacteria, from the mesophile Acetobacterium woodii and, recently, from the thermophile Thermoanaerobacter kivui. Physiological studies toward the importance of the HDCR for growth and formate metabolism in acetogens have not been carried out yet, due to the lack of genetic tools. Here, we deleted the genes encoding HDCR in T. kivui taking advantage of the recently developed genetic system. As expected, the deletion mutant (strain TKV_MB013) did not grow with formate as single substrate or under autotrophic conditions with H2 + CO2. Surprisingly, the strain did also not grow on any other substrate (sugars, mannitol or pyruvate), except for when formate was added. Concentrated cell suspensions quickly consumed formate in the presence of glucose only. In conclusion, HDCR provides formate which was essential for growth of the T. kivui mutant. Alternatively, extracellularly added formate served as terminal electron acceptor in addition to CO2, complementing the growth deficiency. The results show a tight coupling of multi-carbon substrate oxidation to the WLP. The metabolism in the mutant can be viewed as a coupled formate + CO2 respiration, which may be an ancient metabolic trait.
Collapse
Affiliation(s)
- Surbhi Jain
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Helge M Dietrich
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Volker Müller
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Mirko Basen
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| |
Collapse
|
14
|
Schoelmerich MC, Müller V. Energy-converting hydrogenases: the link between H 2 metabolism and energy conservation. Cell Mol Life Sci 2019; 77:1461-1481. [PMID: 31630229 DOI: 10.1007/s00018-019-03329-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/17/2019] [Accepted: 10/01/2019] [Indexed: 10/25/2022]
Abstract
The reversible interconversion of molecular hydrogen and protons is one of the most ancient microbial metabolic reactions and catalyzed by hydrogenases. A widespread yet largely enigmatic group comprises multisubunit [NiFe] hydrogenases, that directly couple H2 metabolism to the electrochemical ion gradient across the membranes of bacteria and of archaea. These complexes are collectively referred to as energy-converting hydrogenases (Ech), as they reversibly transform redox energy into physicochemical energy. Redox energy is typically provided by a low potential electron donor such as reduced ferredoxin to fuel H2 evolution and the establishment of a transmembrane electrochemical ion gradient ([Formula: see text]). The [Formula: see text] is then utilized by an ATP synthase for energy conservation by generating ATP. This review describes the modular structure/function of Ech complexes, focuses on insights into the energy-converting mechanisms, describes the evolutionary context and delves into the implications of relying on an Ech complex as respiratory enzyme for microbial metabolism.
Collapse
Affiliation(s)
- Marie Charlotte Schoelmerich
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany.,Microbiology and Biotechnology, Institute of Plant Sciences and Microbiology, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany
| | - Volker Müller
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany.
| |
Collapse
|
15
|
Moore JP, Li H, Engmann ML, Bischof KM, Kunka KS, Harris ME, Tancredi AC, Ditmars FS, Basting PJ, George NS, Bhagwat AA, Slonczewski JL. Inverted Regulation of Multidrug Efflux Pumps, Acid Resistance, and Porins in Benzoate-Evolved Escherichia coli K-12. Appl Environ Microbiol 2019; 85:e00966-19. [PMID: 31175192 PMCID: PMC6677852 DOI: 10.1128/aem.00966-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 05/30/2019] [Indexed: 01/23/2023] Open
Abstract
Benzoic acid, a partial uncoupler of the proton motive force (PMF), selects for sensitivity to chloramphenicol and tetracycline during the experimental evolution of Escherichia coli K-12. Transcriptomes of E. coli isolates evolved with benzoate showed the reversal of benzoate-dependent regulation, including the downregulation of multidrug efflux pump genes, the gene for the Gad acid resistance regulon, the nitrate reductase genes narHJ, and the gene for the acid-consuming hydrogenase Hyd-3. However, the benzoate-evolved strains had increased expression of OmpF and other large-hole porins that admit fermentable substrates and antibiotics. Candidate genes identified from benzoate-evolved strains were tested for their roles in benzoate tolerance and in chloramphenicol sensitivity. Benzoate or salicylate tolerance was increased by deletion of the Gad activator ariR or of the acid fitness island from slp to the end of the gadX gene encoding Gad regulators and the multidrug pump genes mdtEF Benzoate tolerance was also increased by deletion of multidrug component gene emrA, RpoS posttranscriptional regulator gene cspC, adenosine deaminase gene add, hydrogenase gene hyc (Hyd-3), and the RNA chaperone/DNA-binding regulator gene hfq Chloramphenicol resistance was decreased by mutations in genes for global regulators, such as RNA polymerase alpha subunit gene rpoA, the Mar activator gene rob, and hfq Deletion of lipopolysaccharide biosynthetic kinase gene rfaY decreased the rate of growth in chloramphenicol. Isolates from experimental evolution with benzoate had many mutations affecting aromatic biosynthesis and catabolism, such as aroF (encoding tyrosine biosynthesis) and apt (encoding adenine phosphoribosyltransferase). Overall, benzoate or salicylate exposure selects for the loss of multidrug efflux pumps and of hydrogenases that generate a futile cycle of PMF and upregulates porins that admit fermentable nutrients and antibiotics.IMPORTANCE Benzoic acid is a common food preservative, and salicylic acid (2-hydroxybenzoic acid) is the active form of aspirin. At high concentrations, benzoic acid conducts a proton across the membrane, depleting the proton motive force. In the absence of antibiotics, benzoate exposure selects against proton-driven multidrug efflux pumps and upregulates porins that admit fermentable substrates but that also allow the entry of antibiotics. Thus, evolution with benzoate and related molecules, such as salicylates, requires a trade-off for antibiotic sensitivity, a trade-off that could help define a stable gut microbiome. Benzoate and salicylate are naturally occurring plant signal molecules that may modulate the microbiomes of plants and animal digestive tracts so as to favor fermenters and exclude drug-resistant pathogens.
Collapse
Affiliation(s)
- Jeremy P Moore
- Department of Biology, Kenyon College, Gambier, Ohio, USA
| | - Haofan Li
- Department of Biology, Kenyon College, Gambier, Ohio, USA
| | | | | | - Karina S Kunka
- Department of Biology, Kenyon College, Gambier, Ohio, USA
| | - Mary E Harris
- Department of Biology, Kenyon College, Gambier, Ohio, USA
| | | | | | | | - Nadja S George
- Environmental Microbiology and Food Safety Laboratory, Beltsville Agricultural Research Center, U.S. Department of Agriculture, Beltsville, Maryland, USA
| | - Arvind A Bhagwat
- Environmental Microbiology and Food Safety Laboratory, Beltsville Agricultural Research Center, U.S. Department of Agriculture, Beltsville, Maryland, USA
| | | |
Collapse
|
16
|
Karapetyan L, Valle A, Bolivar J, Trchounian A, Trchounian K. Evidence for Escherichia coli DcuD carrier dependent F OF 1-ATPase activity during fermentation of glycerol. Sci Rep 2019; 9:4279. [PMID: 30862913 PMCID: PMC6414658 DOI: 10.1038/s41598-019-41044-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 02/27/2019] [Indexed: 01/11/2023] Open
Abstract
During fermentation Escherichia coli excrete succinate mainly via Dcu family carriers. Current work reveals the total and N,N'-dicyclohexylcarbodiimide (DCCD) inhibited ATPase activity at pH 7.5 and 5.5 in E. coli wild type and dcu mutants upon glycerol fermentation. The overall ATPase activity was highest at pH 7.5 in dcuABCD mutant. In wild type cells 50% of the activity came from the FOF1-ATPase but in dcuD mutant it reached ~80%. K+ (100 mM) stimulate total but not DCCD inhibited ATPase activity 40% and 20% in wild type and dcuD mutant, respectively. 90% of overall ATPase activity was inhibited by DCCD at pH 5.5 only in dcuABC mutant. At pH 7.5 the H+ fluxes in E. coli wild type, dcuD and dcuABCD mutants was similar but in dcuABC triple mutant the H+ flux decreased 1.4 fold reaching 1.15 mM/min when glycerol was supplemented. In succinate assays the H+ flux was higher in the strains where DcuD is absent. No significant differences were determined in wild type and mutants specific growth rate except dcuD strain. Taken together it is suggested that during glycerol fermentation DcuD has impact on H+ fluxes, FOF1-ATPase activity and depends on potassium ions.
Collapse
Affiliation(s)
- L Karapetyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia
| | - A Valle
- Department of Biomedicine, Biotechnology and Public Health-Biochemistry and Molecular Biology, Institute of Biomolecules (INBIO), University of Cádiz, Avda. República Saharui s/n, 11510, Puerto Real, Cádiz, Spain
| | - J Bolivar
- Department of Biomedicine, Biotechnology and Public Health-Biochemistry and Molecular Biology, Institute of Biomolecules (INBIO), University of Cádiz, Avda. República Saharui s/n, 11510, Puerto Real, Cádiz, Spain
| | - A Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia
- Scientific-Research Institute of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia
| | - K Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia.
- Scientific-Research Institute of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia.
- Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia.
| |
Collapse
|
17
|
Gabrielyan L, Hovhannisyan A, Gevorgyan V, Ananyan M, Trchounian A. Antibacterial effects of iron oxide (Fe 3O 4) nanoparticles: distinguishing concentration-dependent effects with different bacterial cells growth and membrane-associated mechanisms. Appl Microbiol Biotechnol 2019; 103:2773-2782. [PMID: 30706116 DOI: 10.1007/s00253-019-09653-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/14/2019] [Accepted: 01/16/2019] [Indexed: 12/12/2022]
Abstract
Nowadays, the influence of nanoparticles (NPs) on microorganisms attracts a great deal of attention as an alternative to antibiotics. Iron oxide (Fe3O4) NPs' effects on Gram-negative Escherichia coli BW 25113 and Gram-positive Enterococcus hirae ATCC 9790 growth and membrane-associated mechanisms have been investigated in this study. Growth specific rate of E. coli was decreased, indicating the bactericidal effect of Fe3O4 NPs. This inhibitory effect of NPs had a concentration-dependent manner. The reactive oxygen species together with superoxide radicals and singlet oxygen formed by Fe3O4 NPs could be the inhibition cause. Fe3O4 NPs showed opposite effects on E. hirae: the growth stimulation or inhibition was observed depending on NPs concentration used. Addition of NPs altered redox potential kinetics and inhibited H2 yield in E. coli; no change in intracellular pH was determined. Fe3O4 NPs decreased H+-fluxes through bacterial membrane more in E. coli than in E. hirae even in the presence of DCCD and increased ATPase activity more in E. hirae than in E. coli. Our results showed that the Fe3O4 NPs demonstrate differentiating effects on Gram-negative and Gram-positive bacteria likely due to the differences in bacterial cell wall structure and metabolic peculiarities. Fe3O4 NPs of different concentrations have no hemolytic (cytotoxic) activity against erythrocytes. Therefore, they can be proposed as antibacterial agents in biomedicine, biotechnology, and pharmaceutics.
Collapse
Affiliation(s)
- Lilit Gabrielyan
- Department of Medical Biochemistry and Biotechnology, Russian-Armenian University, 123 H. Emin Str., 0051, Yerevan, Armenia
| | - Ashkhen Hovhannisyan
- Department of Medical Biochemistry and Biotechnology, Russian-Armenian University, 123 H. Emin Str., 0051, Yerevan, Armenia
| | - Vladimir Gevorgyan
- Department of Technology for Materials and Electronic Technique Structures, Russian-Armenian University, 123 H. Emin Str., 0051, Yerevan, Armenia
| | - Michail Ananyan
- "Nano-industry" Concern, 4 Bardin Str., 1 bulk, 119334, Moscow, Russia
| | - Armen Trchounian
- Department of Medical Biochemistry and Biotechnology, Russian-Armenian University, 123 H. Emin Str., 0051, Yerevan, Armenia.
| |
Collapse
|
18
|
Fermentation Revisited: How Do Microorganisms Survive Under Energy-Limited Conditions? Trends Biochem Sci 2019; 44:391-400. [PMID: 30655166 DOI: 10.1016/j.tibs.2018.12.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 12/19/2018] [Accepted: 12/21/2018] [Indexed: 12/22/2022]
Abstract
During fermentation FOF1 hydrolyzes ATP, coupling proton transport to proton-motive force (pmf) generation. Despite that, pmf generated by ATP hydrolysis does not satisfy the energy budget of a fermenting cell. However, pmf can also be generated by extrusion of weak organic acids such as lactate and by hydrogen cycling catalyzed by hydrogenases (Hyds). Here we highlight recent advances in our understanding of how the transport of weak organic acids and enzymes contributes to pmf generation during fermentation. The potential impact of these processes on metabolism and energy conservation during microbial fermentation have been overlooked and they not only expand on Mitchell's chemiosmotic theory but also are of relevance to the fields of microbial biochemistry and human and animal health.
Collapse
|
19
|
Schuchmann K, Chowdhury NP, Müller V. Complex Multimeric [FeFe] Hydrogenases: Biochemistry, Physiology and New Opportunities for the Hydrogen Economy. Front Microbiol 2018; 9:2911. [PMID: 30564206 PMCID: PMC6288185 DOI: 10.3389/fmicb.2018.02911] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 11/13/2018] [Indexed: 12/03/2022] Open
Abstract
Hydrogenases are key enzymes of the energy metabolism of many microorganisms. Especially in anoxic habitats where molecular hydrogen (H2) is an important intermediate, these enzymes are used to expel excess reducing power by reducing protons or they are used for the oxidation of H2 as energy and electron source. Despite the fact that hydrogenases catalyze the simplest chemical reaction of reducing two protons with two electrons it turned out that they are often parts of multimeric enzyme complexes catalyzing complex chemical reactions with a multitude of functions in the metabolism. Recent findings revealed multimeric hydrogenases with so far unknown functions particularly in bacteria from the class Clostridia. The discovery of [FeFe] hydrogenases coupled to electron bifurcating subunits solved the enigma of how the otherwise highly endergonic reduction of the electron carrier ferredoxin can be carried out and how H2 production from NADH is possible. Complexes of [FeFe] hydrogenases with formate dehydrogenases revealed a novel enzymatic coupling of the two electron carriers H2 and formate. These novel hydrogenase enzyme complex could also contribute to biotechnological H2 production and H2 storage, both processes essential for an envisaged economy based on H2 as energy carrier.
Collapse
Affiliation(s)
- Kai Schuchmann
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Nilanjan Pal Chowdhury
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Volker Müller
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| |
Collapse
|
20
|
Soghomonyan D, Trchounian A. The survival of irradiated lactobacilli in the simulated gastrointestinal conditions with antibiotic ceftazidime. Lett Appl Microbiol 2018; 68:31-37. [PMID: 30269343 DOI: 10.1111/lam.13080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/22/2018] [Accepted: 09/24/2018] [Indexed: 01/09/2023]
Abstract
Lactobacillus acidophilus is one of the widespread probiotic bacteria that can overcome acid and bile barrier of stomach and intestine, respectively, and then have beneficial effects on the host improving its intestinal microbial balance. The cell membrane FO F1 -ATPase is an important factor in the response and tolerance to low pH through the action of controlling the H+ concentration between the cell cytoplasm and external medium. In this study, the effects of extremely high-frequency EMI at the frequencies of 51·8 GHz and 53 GHz and cetfazidime ( μmol l-1 ) on survival of L. acidophilus VKM B-1660 in the gastrointestinal model in vitro and on ATPase activity of their membrane vesicles were investigated. Irradiated L. acidophilus survived in media with acid pH; the irradiation stimulated N,N'-dicyclohexylcarbodiimide-sensitive FO F1 -ATPase activity under acidic conditions, but enhanced the inhibitory effects of ceftazidime. Probably irradiated L. acidophilus is overcoming the acid barrier even in the presence of ceftazidime due to the FO F1 -ATPase. The obtained results can allow the use of L. acidophilus in food industry, veterinary and medicine. SIGNIFICANCE AND IMPACT OF THE STUDY: The probiotic property of lactobacilli is defined with survival in different conditions of human digestive tract even in the presence of antibiotics and subjected to electromagnetic irradiation (EMI) at the extremely high frequency. Despite the fact that EMI and antibiotic ceftazidime affected Lactobacillus acidophilus; the viable number of bacterial cells was decreased in in vitro gastrointestinal model, but they could to grow in fresh growth medium. The changes in the FO F1 -ATPase activity were obtained at acidic pH. Thus, these bacteria can overcome acid barrier due to the FO F1 -ATPase: the irradiation stimulates the FO F1 -ATPase activity in the acidic conditions, but enhances the effects of ceftazidime. The results are important for identifying the mechanisms of lactobacilli survival for physical and chemical factors and valuable for use.
Collapse
Affiliation(s)
- D Soghomonyan
- Research Institute of Biology, Yerevan State University, Yerevan, Armenia
| | - A Trchounian
- Research Institute of Biology, Yerevan State University, Yerevan, Armenia.,Department of Biochemistry, Microbiology and Biotechnology, Yerevan State University, Yerevan, Armenia
| |
Collapse
|
21
|
Gevorgyan H, Trchounian A, Trchounian K. Understanding the Role ofEscherichia coliHydrogenases and Formate Dehydrogenases in the FOF1-ATPase Activity during the Mixed Acid Fermentation of Mixture of Carbon Sources. IUBMB Life 2018; 70:1040-1047. [DOI: 10.1002/iub.1915] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 06/16/2018] [Accepted: 06/25/2018] [Indexed: 02/02/2023]
Affiliation(s)
- Heghine Gevorgyan
- Department of Biochemistry, Microbiology and Biotechnology; Faculty of Biology, Yerevan State University; Yerevan Armenia
| | - Armen Trchounian
- Department of Biochemistry, Microbiology and Biotechnology; Faculty of Biology, Yerevan State University; Yerevan Armenia
- Scientific-Research Institute of Biology, Faculty of Biology; Yerevan State University; Yerevan Armenia
| | - Karen Trchounian
- Scientific-Research Institute of Biology, Faculty of Biology; Yerevan State University; Yerevan Armenia
| |
Collapse
|
22
|
Protein- and RNA-Enhanced Fermentation by Gut Microbiota of the Earthworm Lumbricus terrestris. Appl Environ Microbiol 2018; 84:AEM.00657-18. [PMID: 29602789 PMCID: PMC5960956 DOI: 10.1128/aem.00657-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 03/23/2018] [Indexed: 11/24/2022] Open
Abstract
Earthworms are a dominant macrofauna in soil ecosystems and have determinative effects on soil fertility and plant growth. These invertebrates feed on ingested material, and gizzard-linked disruption of ingested fungal and bacterial cells is conceived to provide diverse biopolymers in the anoxic alimentary canals of earthworms. Fermentation in the gut is likely important to the utilization of ingested biopolymer-derived compounds by the earthworm. This study therefore examined the fermentative responses of gut content-associated microbes of the model earthworm Lumbricus terrestris to (i) microbial cell lysate (to simulate gizzard-disrupted cells) and (ii) dominant biopolymers of such biomass, protein, and RNA. The microbial cell lysate augmented the production of H2, CO2, and diverse fatty acids (e.g., formate, acetate, propionate, succinate, and butyrate) in anoxic gut content microcosms, indicating that the cell lysate triggered diverse fermentations. Protein and RNA also augmented diverse fermentations in anoxic microcosms of gut contents, each yielding a distinct product profile (e.g., RNA yielded H2 and succinate, whereas protein did not). The combined product profile of protein and RNA treatments was similar to that of cell lysate treatments, and 16S rRNA-based analyses indicated that many taxa that responded to cell lysate were similar to taxa that responded to protein or RNA. In particular, protein stimulated Peptostreptococcaceae, Clostridiaceae, and Fusobacteriaceae, whereas RNA stimulated Aeromonadaceae. These findings demonstrate the capacity of gut-associated obligate anaerobes and facultative aerobes to catalyze biopolymer-driven fermentations and highlight the potential importance of protein and RNA as substrates linked to the overall turnover dynamics of organic carbon in the alimentary canal of the earthworm. IMPORTANCE The subsurface lifestyle of earthworms makes them an unnoticed component of the terrestrial biosphere. However, the propensity of these invertebrates to consume their home, i.e., soil and litter, has long-term impacts on soil fertility, plant growth, and the cycling of elements. The alimentary canals of earthworms can contain up to 500 ml anoxic gut content per square meter of soil, and ingested soil may contain 109 or more microbial cells per gram dry weight, considerations that illustrate that enormous numbers of soil microbes are subject to anoxia during gut passage. Feeding introduces diverse sources of biopolymers to the gut, and the gut fermentation of biopolymers could be important to the transformation of matter by the earthworm and its capacity to utilize fermentation-derived fatty acids. Thus, this study examined the capacity of microbes in earthworm gut contents to ferment protein and RNA, dominant biopolymers of cells that become disrupted during gut passage.
Collapse
|
23
|
Abstract
Numerous recent developments in the biochemistry, molecular biology, and physiology of formate and H2 metabolism and of the [NiFe]-hydrogenase (Hyd) cofactor biosynthetic machinery are highlighted. Formate export and import by the aquaporin-like pentameric formate channel FocA is governed by interaction with pyruvate formate-lyase, the enzyme that generates formate. Formate is disproportionated by the reversible formate hydrogenlyase (FHL) complex, which has been isolated, allowing biochemical dissection of evolutionary parallels with complex I of the respiratory chain. A recently identified sulfido-ligand attached to Mo in the active site of formate dehydrogenases led to the proposal of a modified catalytic mechanism. Structural analysis of the homologous, H2-oxidizing Hyd-1 and Hyd-5 identified a novel proximal [4Fe-3S] cluster in the small subunit involved in conferring oxygen tolerance to the enzymes. Synthesis of Salmonella Typhimurium Hyd-5 occurs aerobically, which is novel for an enterobacterial Hyd. The O2-sensitive Hyd-2 enzyme has been shown to be reversible: it presumably acts as a conformational proton pump in the H2-oxidizing mode and is capable of coupling reverse electron transport to drive H2 release. The structural characterization of all the Hyp maturation proteins has given new impulse to studies on the biosynthesis of the Fe(CN)2CO moiety of the [NiFe] cofactor. It is synthesized on a Hyp-scaffold complex, mainly comprising HypC and HypD, before insertion into the apo-large subunit. Finally, clear evidence now exists indicating that Escherichia coli can mature Hyd enzymes differentially, depending on metal ion availability and the prevailing metabolic state. Notably, Hyd-3 of the FHL complex takes precedence over the H2-oxidizing enzymes.
Collapse
|
24
|
Chen G, Kleindienst S, Griffiths DR, Mack EE, Seger ES, Löffler FE. Mutualistic interaction between dichloromethane- and chloromethane-degrading bacteria in an anaerobic mixed culture. Environ Microbiol 2017; 19:4784-4796. [DOI: 10.1111/1462-2920.13945] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 09/19/2017] [Accepted: 09/22/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Gao Chen
- Center for Environmental Biotechnology; University of Tennessee; Knoxville TN 37996 USA
- Department of Civil and Environmental Engineering; University of Tennessee; Knoxville TN 37996 USA
| | - Sara Kleindienst
- Center for Environmental Biotechnology; University of Tennessee; Knoxville TN 37996 USA
- Oak Ridge National Laboratory; University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division; Oak Ridge TN 37831 USA
- Center for Applied Geosciences; Department of Geosciences, Eberhard Karls University Tübingen; Tübingen 72074 Germany
| | | | - E. Erin Mack
- Corporate Remediation Group; E. I. DuPont de Nemours and Company; Wilmington DE 19805 USA
| | | | - Frank E. Löffler
- Center for Environmental Biotechnology; University of Tennessee; Knoxville TN 37996 USA
- Department of Civil and Environmental Engineering; University of Tennessee; Knoxville TN 37996 USA
- Oak Ridge National Laboratory; University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division; Oak Ridge TN 37831 USA
- Department of Microbiology; University of Tennessee; Knoxville TN 37996 USA
- Department of Biosystems Engineering and Soil Science; University of Tennessee; Knoxville TN 37996 USA
| |
Collapse
|
25
|
Pinske C, Sargent F. Exploring the directionality of Escherichia coli formate hydrogenlyase: a membrane-bound enzyme capable of fixing carbon dioxide to organic acid. Microbiologyopen 2016; 5:721-737. [PMID: 27139710 PMCID: PMC5061711 DOI: 10.1002/mbo3.365] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 03/14/2016] [Accepted: 03/23/2016] [Indexed: 12/31/2022] Open
Abstract
During mixed‐acid fermentation Escherichia coli produces formate, which is initially excreted out the cell. Accumulation of formate, and dropping extracellular pH, leads to biosynthesis of the formate hydrogenlyase (FHL) complex. FHL consists of membrane and soluble domains anchored within the inner membrane. The soluble domain comprises a [NiFe] hydrogenase and a formate dehydrogenase that link formate oxidation directly to proton reduction with the release of CO2 and H2. Thus, the function of FHL is to oxidize excess formate at low pH. FHL subunits share identity with subunits of the respiratory Complex I. In particular, the FHL membrane domain contains subunits (HycC and HycD) that are homologs of NuoL/M/N and NuoH, respectively, which have been implicated in proton translocation. In this work, strain engineering and new assays demonstrate unequivocally the nonphysiological reverse activity of FHL in vivo and in vitro. Harnessing FHL to reduce CO2 to formate is biotechnologically important. Moreover, assays for both possible FHL reactions provide opportunities to explore the bioenergetics using biochemical and genetic approaches. Comprehensive mutagenesis of hycC did not identify any single amino acid residues essential for FHL operation. However, the HycD E199, E201, and E203 residues were found to be critically important for FHL function.
Collapse
Affiliation(s)
- Constanze Pinske
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, Scotland, DD1 5EH, United Kingdom
| | - Frank Sargent
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, Scotland, DD1 5EH, United Kingdom.
| |
Collapse
|
26
|
Hunger S, Schmidt O, Gößner AS, Drake HL. Formate-derived H2, a driver of hydrogenotrophic processes in the root-zone of a methane-emitting fen. Environ Microbiol 2016; 18:3106-19. [DOI: 10.1111/1462-2920.13301] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 03/12/2016] [Indexed: 02/04/2023]
Affiliation(s)
- Sindy Hunger
- Department of Ecological Microbiology; University of Bayreuth; 95440 Bayreuth Germany
| | - Oliver Schmidt
- Department of Ecological Microbiology; University of Bayreuth; 95440 Bayreuth Germany
| | - Anita S. Gößner
- Department of Ecological Microbiology; University of Bayreuth; 95440 Bayreuth Germany
| | - Harold L. Drake
- Department of Ecological Microbiology; University of Bayreuth; 95440 Bayreuth Germany
| |
Collapse
|
27
|
Soghomonyan D, Trchounian K, Trchounian A. Millimeter waves or extremely high frequency electromagnetic fields in the environment: what are their effects on bacteria? Appl Microbiol Biotechnol 2016; 100:4761-71. [DOI: 10.1007/s00253-016-7538-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 04/02/2016] [Accepted: 04/05/2016] [Indexed: 12/11/2022]
|
28
|
Zhang W, Yang L, Li M, Ma B, Yan C, Chen J. Omics-Based Comparative Transcriptional Profiling of Two Contrasting Rice Genotypes during Early Infestation by Small Brown Planthopper. Int J Mol Sci 2015; 16:28746-64. [PMID: 26633389 PMCID: PMC4691075 DOI: 10.3390/ijms161226128] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Revised: 11/02/2015] [Accepted: 11/04/2015] [Indexed: 11/16/2022] Open
Abstract
The small brown planthopper (SBPH) is one of the destructive pests of rice. Although different biochemical pathways that are involved in rice responding to planthopper infestation have been documented, it is unclear which individual metabolic pathways are responsive to planthopper infestation. In this study, an omics-based comparative transcriptional profiling of two contrasting rice genotypes, an SBPH-resistant and an SBPH-susceptible rice line, was assessed for rice individual metabolic pathways responsive to SBPH infestation. When exposed to SBPH, 166 metabolic pathways were differentially regulated; of these, more than one-third of metabolic pathways displayed similar change patterns between these two contrasting rice genotypes; the difference of change pattern between these two contrasting rice genotypes mostly lies in biosynthetic pathways and the obvious difference of change pattern lies in energy metabolism pathways. Combining the Pathway Tools Omics Viewer with the web tool Venn, 21 and 6 metabolic pathways which potentially associated with SBPH resistance and susceptibility, respectively were identified. This study presents an omics-based comparative transcriptional profiling of SBPH-resistant and SBPH-susceptible rice plants during early infestation by SBPH, which will be very informative in studying rice-insect interaction. The results will provide insight into how rice plants respond to early infestation by SBPH from the biochemical pathways perspective.
Collapse
Affiliation(s)
- Weilin Zhang
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China.
| | - Ling Yang
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China.
| | - Mei Li
- Analysis Center of Agrobiology and Environmental Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Bojun Ma
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China.
| | - Chengqi Yan
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Ministry of China Key Laboratory of Biotechnology in Plant Protection, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
| | - Jianping Chen
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Ministry of China Key Laboratory of Biotechnology in Plant Protection, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
| |
Collapse
|
29
|
Blbulyan S, Trchounian A. Impact of membrane-associated hydrogenases on the FOF1-ATPase in Escherichia coli during glycerol and mixed carbon fermentation: ATPase activity and its inhibition by N,N′-dicyclohexylcarbodiimide in the mutants lacking hydrogenases. Arch Biochem Biophys 2015; 579:67-72. [DOI: 10.1016/j.abb.2015.05.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 05/28/2015] [Accepted: 05/29/2015] [Indexed: 10/23/2022]
|
30
|
Spaans SK, Weusthuis RA, van der Oost J, Kengen SWM. NADPH-generating systems in bacteria and archaea. Front Microbiol 2015; 6:742. [PMID: 26284036 PMCID: PMC4518329 DOI: 10.3389/fmicb.2015.00742] [Citation(s) in RCA: 197] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 07/06/2015] [Indexed: 12/22/2022] Open
Abstract
Reduced nicotinamide adenine dinucleotide phosphate (NADPH) is an essential electron donor in all organisms. It provides the reducing power that drives numerous anabolic reactions, including those responsible for the biosynthesis of all major cell components and many products in biotechnology. The efficient synthesis of many of these products, however, is limited by the rate of NADPH regeneration. Hence, a thorough understanding of the reactions involved in the generation of NADPH is required to increase its turnover through rational strain improvement. Traditionally, the main engineering targets for increasing NADPH availability have included the dehydrogenase reactions of the oxidative pentose phosphate pathway and the isocitrate dehydrogenase step of the tricarboxylic acid (TCA) cycle. However, the importance of alternative NADPH-generating reactions has recently become evident. In the current review, the major canonical and non-canonical reactions involved in the production and regeneration of NADPH in prokaryotes are described, and their key enzymes are discussed. In addition, an overview of how different enzymes have been applied to increase NADPH availability and thereby enhance productivity is provided.
Collapse
Affiliation(s)
| | - Ruud A. Weusthuis
- Bioprocess Engineering, Wageningen UniversityWageningen, Netherlands
| | - John van der Oost
- Laboratory of Microbiology, Wageningen UniversityWageningen, Netherlands
| | - Servé W. M. Kengen
- Laboratory of Microbiology, Wageningen UniversityWageningen, Netherlands
| |
Collapse
|
31
|
Valle A, Cabrera G, Cantero D, Bolivar J. Identification of enhanced hydrogen and ethanol Escherichia coli producer strains in a glycerol-based medium by screening in single-knock out mutant collections. Microb Cell Fact 2015; 14:93. [PMID: 26122736 PMCID: PMC4485358 DOI: 10.1186/s12934-015-0285-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 06/16/2015] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Earth's climate is warming as a result of anthropogenic emissions of greenhouse gases from fossil fuel combustion. Bioenergy, which includes biodiesel, biohydrogen and bioethanol, has emerged as a sustainable alternative fuel source. For this reason, in recent years biodiesel production has become widespread but this industry currently generates a huge amount of glycerol as a by-product, which has become an environmental problem in its own right. A feasible possibility to solve this problem is the use of waste glycerol as a carbon source for microbial transformation into biofuels such as hydrogen and ethanol. For instance, Escherichia coli is a microorganism that can synthesize these compounds under anaerobic conditions. RESULTS In this work an experimental procedure was established for screening E. coli single mutants to identify strains with enhanced ethanol and/or H2 productions compared to the wild type strain. In an initial screening of 150 single mutants, 12 novel strains (gnd, tdcE, rpiA nanE, tdcB, deoB, sucB, cpsG, frmA, glgC, fumA and gadB) were found to provide enhanced yields for at least one of the target products. The mutations, that improve most significantly the parameters evaluated (gnd and tdcE genes), were combined with other mutations in three engineered E. coli mutant strains in order to further redirect carbon flux towards the desired products. CONCLUSIONS This methodology can be a useful tool to disclose the metabolic pathways that are more susceptible to manipulation in order to obtain higher molar yields of hydrogen and ethanol using glycerol as main carbon source in multiple E. coli mutants.
Collapse
Affiliation(s)
- Antonio Valle
- Department of Biomedicine, Biotechnology and Public Health-Biochemistry and Molecular Biology, Campus de Excelencia Internacional Agroalimentario (ceiA3), Institute of Biomolecules, University of Cádiz, Avda República Saharui s/n, 11510, Puerto Real, Cádiz, Spain.
| | - Gema Cabrera
- Department of Chemical Engineering and Food Technology, Campus de Excelencia Internacional Agroalimentario (ceiA3), University of Cádiz, Avda República Saharui s/n, 11510, Puerto Real, Cádiz, Spain.
| | - Domingo Cantero
- Department of Chemical Engineering and Food Technology, Campus de Excelencia Internacional Agroalimentario (ceiA3), University of Cádiz, Avda República Saharui s/n, 11510, Puerto Real, Cádiz, Spain.
| | - Jorge Bolivar
- Department of Biomedicine, Biotechnology and Public Health-Biochemistry and Molecular Biology, Campus de Excelencia Internacional Agroalimentario (ceiA3), Institute of Biomolecules, University of Cádiz, Avda República Saharui s/n, 11510, Puerto Real, Cádiz, Spain.
| |
Collapse
|
32
|
Vivijs B, Haberbeck LU, Baiye Mfortaw Mbong V, Bernaerts K, Geeraerd AH, Aertsen A, Michiels CW. Formate hydrogen lyase mediates stationary-phase deacidification and increases survival during sugar fermentation in acetoin-producing enterobacteria. Front Microbiol 2015; 6:150. [PMID: 25762991 PMCID: PMC4340222 DOI: 10.3389/fmicb.2015.00150] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 02/09/2015] [Indexed: 12/02/2022] Open
Abstract
Two fermentation types exist in the Enterobacteriaceae family. Mixed-acid fermenters produce substantial amounts of lactate, formate, acetate, and succinate, resulting in lethal medium acidification. On the other hand, 2,3-butanediol fermenters switch to the production of the neutral compounds acetoin and 2,3-butanediol and even deacidify the environment after an initial acidification phase, thereby avoiding cell death. We equipped three mixed-acid fermenters (Salmonella Typhimurium, S. Enteritidis and Shigella flexneri) with the acetoin pathway from Serratia plymuthica to investigate the mechanisms of deacidification. Acetoin production caused attenuated acidification during exponential growth in all three bacteria, but stationary-phase deacidification was only observed in Escherichia coli and Salmonella, suggesting that it was not due to the consumption of protons accompanying acetoin production. To identify the mechanism, 34 transposon mutants of acetoin-producing E. coli that no longer deacidified the culture medium were isolated. The mutations mapped to 16 genes, all involved in formate metabolism. Formate is an end product of mixed-acid fermentation that can be converted to H2 and CO2 by the formate hydrogen lyase (FHL) complex, a reaction that consumes protons and thus can explain medium deacidification. When hycE, encoding the large subunit of hydrogenase 3 that is part of the FHL complex, was deleted in acetoin-producing E. coli, deacidification capacity was lost. Metabolite analysis in E. coli showed that introduction of the acetoin pathway reduced lactate and acetate production, but increased glucose consumption and formate and ethanol production. Analysis of a hycE mutant in S. plymuthica confirmed that medium deacidification in this organism is also mediated by FHL. These findings improve our understanding of the physiology and function of fermentation pathways in Enterobacteriaceae.
Collapse
Affiliation(s)
- Bram Vivijs
- Laboratory of Food Microbiology and Leuven Food Science and Nutrition Research Centre, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, KU Leuven Leuven, Belgium
| | - Leticia U Haberbeck
- Laboratory of Food Microbiology and Leuven Food Science and Nutrition Research Centre, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, KU Leuven Leuven, Belgium ; Division of Mechatronics, Biostatistics and Sensors, Department of Biosystems, Faculty of Bioscience Engineering, KU Leuven Leuven, Belgium
| | - Victor Baiye Mfortaw Mbong
- Division of Mechatronics, Biostatistics and Sensors, Department of Biosystems, Faculty of Bioscience Engineering, KU Leuven Leuven, Belgium
| | - Kristel Bernaerts
- Chemical and Biochemical Process Technology and Control Section, Department of Chemical Engineering, Faculty of Engineering Science KU Leuven, Leuven, Belgium
| | - Annemie H Geeraerd
- Division of Mechatronics, Biostatistics and Sensors, Department of Biosystems, Faculty of Bioscience Engineering, KU Leuven Leuven, Belgium
| | - Abram Aertsen
- Laboratory of Food Microbiology and Leuven Food Science and Nutrition Research Centre, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, KU Leuven Leuven, Belgium
| | - Chris W Michiels
- Laboratory of Food Microbiology and Leuven Food Science and Nutrition Research Centre, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, KU Leuven Leuven, Belgium
| |
Collapse
|
33
|
Physiology and bioenergetics of [NiFe]-hydrogenase 2-catalyzed H2-consuming and H2-producing reactions in Escherichia coli. J Bacteriol 2014; 197:296-306. [PMID: 25368299 DOI: 10.1128/jb.02335-14] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Escherichia coli uptake hydrogenase 2 (Hyd-2) catalyzes the reversible oxidation of H2 to protons and electrons. Hyd-2 synthesis is strongly upregulated during growth on glycerol or on glycerol-fumarate. Membrane-associated Hyd-2 is an unusual heterotetrameric [NiFe]-hydrogenase that lacks a typical cytochrome b membrane anchor subunit, which transfers electrons to the quinone pool. Instead, Hyd-2 has an additional electron transfer subunit, termed HybA, with four predicted iron-sulfur clusters. Here, we examined the physiological role of the HybA subunit. During respiratory growth with glycerol and fumarate, Hyd-2 used menaquinone/demethylmenaquinone (MQ/DMQ) to couple hydrogen oxidation to fumarate reduction. HybA was essential for electron transfer from Hyd-2 to MQ/DMQ. H2 evolution catalyzed by Hyd-2 during fermentation of glycerol in the presence of Casamino Acids or in a fumarate reductase-negative strain growing with glycerol-fumarate was also shown to be dependent on both HybA and MQ/DMQ. The uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP) inhibited Hyd-2-dependent H2 evolution from glycerol, indicating the requirement for a proton gradient. In contrast, CCCP failed to inhibit H2-coupled fumarate reduction. Although a Hyd-2 enzyme lacking HybA could not catalyze Hyd-2-dependent H2 oxidation or H2 evolution in whole cells, reversible H2-dependent reduction of viologen dyes still occurred. Finally, hydrogen-dependent dye reduction by Hyd-2 was reversibly inhibited in extracts derived from cells grown in H2 evolution mode. Our findings suggest that Hyd-2 switches between H2-consuming and H2-producing modes in response to the redox status of the quinone pool. Hyd-2-dependent H2 evolution from glycerol requires reverse electron transport.
Collapse
|