1
|
Meißner J, Königshof M, Wrede K, Warneke R, Mardoukhi MSY, Commichau FM, Stülke J. Control of asparagine homeostasis in Bacillus subtilis: identification of promiscuous amino acid importers and exporters. J Bacteriol 2024; 206:e0042023. [PMID: 38193659 PMCID: PMC10882977 DOI: 10.1128/jb.00420-23] [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: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 01/10/2024] Open
Abstract
The Gram-positive model bacterium B. subtilis is able to import all proteinogenic amino acids from the environment as well as to synthesize them. However, the players involved in the acquisition of asparagine have not yet been identified for this bacterium. In this work, we used d-asparagine as a toxic analog of l-asparagine to identify asparagine transporters. This revealed that d- but not l-asparagine is taken up by the malate/lactate antiporter MleN. Specific strains that are sensitive to the presence of l-asparagine due to the lack of the second messenger cyclic di-AMP or due to the intracellular accumulation of this amino acid were used to isolate and characterize suppressor mutants that were resistant to the presence of otherwise growth-inhibiting concentrations of l-asparagine. These screens identified the broad-spectrum amino acid importers AimA and BcaP as responsible for the acquisition of l-asparagine. The amino acid exporter AzlCD allows detoxification of l-asparagine in addition to 4-azaleucine and histidine. This work supports the idea that amino acids are often transported by promiscuous importers and exporters. However, our work also shows that even stereo-enantiomeric amino acids do not necessarily use the same transport systems.IMPORTANCETransport of amino acid is a poorly studied function in many bacteria, including the model organism Bacillus subtilis. The identification of transporters is hampered by the redundancy of transport systems for most amino acids as well as by the poor specificity of the transporters. Here, we apply several strategies to use the growth-inhibitive effect of many amino acids under defined conditions to isolate suppressor mutants that exhibit either reduced uptake or enhanced export of asparagine, resulting in the identification of uptake and export systems for l-asparagine. The approaches used here may be useful for the identification of transporters for other amino acids both in B. subtilis and in other bacteria.
Collapse
Affiliation(s)
- Janek Meißner
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Manuel Königshof
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Katrin Wrede
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Robert Warneke
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | | | - Fabian M. Commichau
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
| | - Jörg Stülke
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| |
Collapse
|
2
|
Abate E, Mehdi M, Addisu S, Degef M, Tebeje S, Kelemu T. Emerging roles of cytosolic phosphoenolpyruvate kinase 1 (PCK1) in cancer. Biochem Biophys Rep 2023; 35:101528. [PMID: 37637941 PMCID: PMC10457690 DOI: 10.1016/j.bbrep.2023.101528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/20/2023] [Accepted: 08/09/2023] [Indexed: 08/29/2023] Open
Abstract
Although it was traditionally believed that gluconeogenesis enzymes were absent from cancers that did not originate in gluconeogenic organs, numerous investigations have shown that they are functionally expressed in a variety of tumors as mediators of shortened forms of Gluconeogenesis. One of the isomers of PEPCK, the first-rate limiting enzyme in gluconeogenesis, is PCK 1, which catalyzes the conversion of oxaloacetate (OAA) and GTP into PEP, CO2, and GDP. It is also known as PEPCK-C or PCK1, and it is cytosolic. Despite being paradoxical, it has been demonstrated that, in addition to its enzymatic role in normal metabolism, this enzyme also plays a role in tumors that arise in gluconeogenic and non-gluconeogenic organs. According to newly available research, it has metabolic and non-metabolic roles in tumor progression and development. Thus, this review will give insight into PCK1 relationship, function, and mechanism in or with different types of cancer using contemporary findings.
Collapse
Affiliation(s)
- Ebsitu Abate
- Department of Medical Biochemistry, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Mohammed Mehdi
- Department of Medical Biochemistry, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Sisay Addisu
- Department of Medical Biochemistry, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Maria Degef
- Department of Medical Biochemistry, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Solomon Tebeje
- Department of Medical Biochemistry, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Tsehayneh Kelemu
- Department of Medical Biochemistry, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| |
Collapse
|
3
|
Wang Z, Zeng Y, Cheng K, Cai Z, Zhou J. The quorum sensing system of Novosphingobium sp. ERN07 regulates aggregate formation that promotes cyanobacterial growth. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 851:158354. [PMID: 36041622 DOI: 10.1016/j.scitotenv.2022.158354] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 08/03/2022] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
Microbial aggregates play key roles in cyanobacterial blooms. Being a bacterial communication mechanism, quorum sensing (QS) synchronizes gene expression in a density-dependent manner and regulates bacterial physiological behavior. However, the regulatory role of QS in the formation of cyanobacteria-associated bacterial aggregates remains poorly understood. Here, we present insight into the role of QS in regulating bacterial aggregate formation in a representative bacterial strain, Novosphingobium sp. ERN07, which was isolated from Microcystis blooms in Lake Taihu. A biosensor assay showed that ERN07 exhibits significant AHL-producing capacity. Biochemical and microscopic analysis revealed that this strain possesses the ability to form aggregated communities. Gene knockout experiments indicated that the AHL-mediated QS system positively regulates bacterial aggregation. The aggregated communities possess the ability to enhance the production of extracellular polymeric substances (EPS), alter EPS composition ratios, and affect biofilm formation. The addition of aggregated substances also has a significant growth-promoting effect on M. aeruginosa. Transcriptomic analysis revealed that the aggregated substances positively regulate photosynthetic efficiency and energy metabolism of M. aeruginosa. These findings show that QS can mediate the aggregation phenotype and associated substrate spectrum composition, contributing to a better understanding of microalgal-bacterial interactions and mechanisms of Microcystis bloom maintenance in the natural environment.
Collapse
Affiliation(s)
- Zhaoyi Wang
- Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong Province, PR China
| | - Yanhua Zeng
- Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong Province, PR China; State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, Hainan Province, PR China
| | - Keke Cheng
- Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong Province, PR China
| | - Zhonghua Cai
- Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong Province, PR China
| | - Jin Zhou
- Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong Province, PR China.
| |
Collapse
|
4
|
Thanamit K, Hoerhold F, Oswald M, Koenig R. Linear programming based gene expression model (LPM-GEM) predicts the carbon source for Bacillus subtilis. BMC Bioinformatics 2022; 23:226. [PMID: 35689204 PMCID: PMC9188260 DOI: 10.1186/s12859-022-04742-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 05/23/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Elucidating cellular metabolism led to many breakthroughs in biotechnology, synthetic biology, and health sciences. To date, deriving metabolic fluxes by 13C tracer experiments is the most prominent approach for studying metabolic fluxes quantitatively, often with high accuracy and precision. However, the technique has a high demand for experimental resources. Alternatively, flux balance analysis (FBA) has been employed to estimate metabolic fluxes without labeling experiments. It is less informative but can benefit from the low costs and low experimental efforts and gain flux estimates in experimentally difficult conditions. Methods to integrate relevant experimental data have been emerged to improve FBA flux estimations. Data from transcription profiling is often selected since it is easy to generate at the genome scale, typically embedded by a discretization of differential and non-differential expressed genes coding for the respective enzymes. RESULT We established the novel method Linear Programming based Gene Expression Model (LPM-GEM). LPM-GEM linearly embeds gene expression into FBA constraints. We implemented three strategies to reduce thermodynamically infeasible loops, which is a necessary prerequisite for such an omics-based model building. As a case study, we built a model of B. subtilis grown in eight different carbon sources. We obtained good flux predictions based on the respective transcription profiles when validating with 13C tracer based metabolic flux data of the same conditions. We could well predict the specific carbon sources. When testing the model on another, unseen dataset that was not used during training, good prediction performance was also observed. Furthermore, LPM-GEM outperformed a well-established model building methods. CONCLUSION Employing LPM-GEM integrates gene expression data efficiently. The method supports gene expression-based FBA models and can be applied as an alternative to estimate metabolic fluxes when tracer experiments are inappropriate.
Collapse
Affiliation(s)
- Kulwadee Thanamit
- Systems Biology Research Group, Institute for Infectious Diseases and Infection Control (IIMK), Jena University Hospital, Kollegiengasse 10, 07743, Jena, Germany
| | - Franziska Hoerhold
- Systems Biology Research Group, Institute for Infectious Diseases and Infection Control (IIMK), Jena University Hospital, Kollegiengasse 10, 07743, Jena, Germany
| | - Marcus Oswald
- Systems Biology Research Group, Institute for Infectious Diseases and Infection Control (IIMK), Jena University Hospital, Kollegiengasse 10, 07743, Jena, Germany
| | - Rainer Koenig
- Systems Biology Research Group, Institute for Infectious Diseases and Infection Control (IIMK), Jena University Hospital, Kollegiengasse 10, 07743, Jena, Germany.
| |
Collapse
|
5
|
On-line monitoring of industrial interest Bacillus fermentations, using impedance spectroscopy. J Biotechnol 2022; 343:52-61. [PMID: 34826536 DOI: 10.1016/j.jbiotec.2021.11.005] [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: 04/15/2021] [Revised: 10/12/2021] [Accepted: 11/13/2021] [Indexed: 11/21/2022]
Abstract
Impedance spectroscopy is a technique used to characterize electrochemical systems, increasing its applicability as well to monitor cell cultures. During their growth, Bacillus species have different phases which involve the production and consumption of different metabolites, culminating in the cell differentiation process that allows the generation of bacterial spores. In order to use impedance spectroscopy as a tool to monitor industrial interest Bacillus cultures, we conducted batch fermentations of Bacillus species such as B. subtilis, B. amyloliquefaciens, and B. licheniformis coupled with this technique. Each fermentation was characterized by the scanning of 50 frequencies between 0.5 and 5 MHz every 30 min. Pearson's correlation between impedance and phase angle profiles (obtained from each frequency scanned) with the kinetic profiles of each strain allowed the selection of fixed frequencies of 0.5, 1.143, and 1.878 MHz to follow-up of the fermentations of B. subtilis, B. amyloliquefaciens and B. licheniformis, respectively. Dielectric profiles of impedance, phase angle, reactance, and resistance obtained at the fixed frequency showed consistent changes with exponential, transition, and spore release phases.
Collapse
|
6
|
Hofmann J, Bitew MA, Kuba M, De Souza DP, Newton HJ, Sansom FM. Characterisation of putative lactate synthetic pathways of Coxiella burnetii. PLoS One 2021; 16:e0255925. [PMID: 34388185 PMCID: PMC8362950 DOI: 10.1371/journal.pone.0255925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 07/26/2021] [Indexed: 11/19/2022] Open
Abstract
The zoonotic pathogen Coxiella burnetii, the causative agent of the human disease Q fever, is an ever-present danger to global public health. Investigating novel metabolic pathways necessary for C. burnetii to replicate within its unusual intracellular niche may identify new therapeutic targets. Recent studies employing stable isotope labelling established the ability of C. burnetii to synthesize lactate, despite the absence of an annotated synthetic pathway on its genome. A noncanonical lactate synthesis pathway could provide a novel anti-Coxiella target if it is essential for C. burnetii pathogenesis. In this study, two C. burnetii proteins, CBU1241 and CBU0823, were chosen for analysis based on their similarities to known lactate synthesizing enzymes. Recombinant GST-CBU1241, a putative malate dehydrogenase (MDH), did not produce measurable lactate in in vitro lactate dehydrogenase (LDH) activity assays and was confirmed to function as an MDH. Recombinant 6xHis-CBU0823, a putative NAD+-dependent malic enzyme, was shown to have both malic enzyme activity and MDH activity, however, did not produce measurable lactate in either LDH or malolactic enzyme activity assays in vitro. To examine potential lactate production by CBU0823 more directly, [13C]glucose labelling experiments compared label enrichment within metabolic pathways of a cbu0823 transposon mutant and the parent strain. No difference in lactate production was observed, but the loss of CBU0823 significantly reduced 13C-incorporation into glycolytic and TCA cycle intermediates. This disruption to central carbon metabolism did not have any apparent impact on intracellular replication within THP-1 cells. This research provides new information about the mechanism of lactate biosynthesis within C. burnetii, demonstrating that CBU1241 is not multifunctional, at least in vitro, and that CBU0823 also does not synthesize lactate. Although critical for normal central carbon metabolism of C. burnetii, loss of CBU0823 did not significantly impair replication of the bacterium inside cells.
Collapse
Affiliation(s)
- Janine Hofmann
- Faculty of Veterinary and Agricultural Sciences, Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, University of Melbourne, Parkville, Victoria, Australia
| | - Mebratu A. Bitew
- Department of Pathology, Microbiology and Immunology, University of California, Davis, California, United States of America
| | - Miku Kuba
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - David P. De Souza
- Metabolomics Australia, The Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Hayley J. Newton
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Fiona M. Sansom
- Faculty of Veterinary and Agricultural Sciences, Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
7
|
Lysinibacillus sphaericus III(3)7 and Plasmid Vector pMK4: New Challenges in Cloning Platforms. MICROBIOLOGY RESEARCH 2021. [DOI: 10.3390/microbiolres12020031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The acquisition and especially the maintenance of a plasmid usually brings a fitness cost that reduces the reproductive rate of the bacterial host; for strains like Lysinibacillus sphaericus III(3)7, which possesses important environmental properties, this alteration along with morphological changes and reduced sporulation rates may exert a negative effect on metabolic studies using plasmids as cloning platforms. The aim of this study is to approach the metabolic behavior of pMK4-bearing cells of L. sphaericus III(3)7 through the use of bioinformatic and in vitro analyses. An incompatibility model between the pMK4 vector and a predicted megaplasmid, pBsph, inside III(3)7 cells was constructed based on an incA region. Additionally, in vitro long-term plasmid stability was not found in plasmid-bearing cells. Alignments between replicons, mobile genetic elements and RNA-RNA interactions were assessed, pairwise alignment visualization, graphic models and morphological changes were evaluated by SEM. Metabolite analysis was done through HPLC coupled to a Q-TOF 6545, and electrospray ionization was used, finally, Aedes aegypti and Culex quinquefasciatus larvae were used for larvicidal activity assessment. Results found, a decreased growth rate, spore formation reduction and morphological changes, which supported the idea of metabolic cost exerted by pMK4. An incompatibility between pMK4 and pBsph appears to take place inside L. sphaericus III(3)7 cells, however, further in vitro studies are needed to confirm it.
Collapse
|
8
|
Investigating Synthesis of the MalS Malic Enzyme during Bacillus subtilis Spore Germination and Outgrowth and the Influence of Spore Maturation and Sporulation Conditions. mSphere 2020; 5:5/4/e00464-20. [PMID: 32759333 PMCID: PMC7407067 DOI: 10.1128/msphere.00464-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The spores formed by Bacillus subtilis remain in a quiescent state for extended periods due to their dormancy and resistance features. Dormancy is linked to a very low level of core water content and a phase-bright state of spores. The present report, focusing on proteins MalS and PdhD (pyruvate dehydrogenase subunit D) and complementary to our companion report published in this issue, aims to shed light on a major dilemma in the field, i.e., whether protein synthesis, in particular that of MalS, takes place in phase-bright spores. Clustered MalS-GFP in dormant spores diffuses throughout the spore as germination proceeds. However, fluorescence intensity measurements, supported by Western blot analysis and SILAC proteomics, confirm that there is no new MalS protein synthesis in bright-phase dormant spores. Spore-forming bacteria of the orders Bacillales and Clostridiales play a major role in food spoilage and foodborne diseases. When environmental conditions become favorable, these spores can germinate as the germinant receptors located on the spore’s inner membrane are activated via germinant binding. This leads to the formation of vegetative cells via germination and subsequent outgrowth and potential deleterious effects on foods. The present report focuses on analysis of the synthesis of the MalS (malic enzyme) protein during Bacillus subtilis spore germination by investigating the dynamics of the presence and fluorescence level of a MalS-GFP (MalS-green fluorescent protein) fusion protein using time-lapse fluorescence microscopy. Our results show an initial increase in MalS-GFP fluorescence intensity within the first 15 min of germination, followed by a discernible drop and stabilization of the fluorescence throughout spore outgrowth as reported previously (L. Sinai, A. Rosenberg, Y. Smith, E. Segev, and S. Ben-Yehuda, Mol Cell 57:695–707, 2015, https://doi.org/10.1016/j.molcel.2014.12.019). However, in contrast to the earlier report, both Western blotting and SILAC (stable isotopic labeling of amino acids in cell culture) analysis showed there was no increase in MalS-GFP levels during the 15 min after the addition of germinants and that MalS synthesis did not begin until more than 90 min after germinant addition. Thus, the increase in MalS-GFP fluorescence early in germination is not due to new protein synthesis but is perhaps due to a change in the physical environment of the spore cores. Our findings also show that different sporulation conditions and spore maturation times affect expression of MalS-GFP and the germination behavior of the spores, albeit to a minor extent, but still result in no changes in MalS-GFP levels early in spore germination. IMPORTANCE The spores formed by Bacillus subtilis remain in a quiescent state for extended periods due to their dormancy and resistance features. Dormancy is linked to a very low level of core water content and a phase-bright state of spores. The present report, focusing on proteins MalS and PdhD (pyruvate dehydrogenase subunit D) and complementary to our companion report published in this issue, aims to shed light on a major dilemma in the field, i.e., whether protein synthesis, in particular that of MalS, takes place in phase-bright spores. Clustered MalS-GFP in dormant spores diffuses throughout the spore as germination proceeds. However, fluorescence intensity measurements, supported by Western blot analysis and SILAC proteomics, confirm that there is no new MalS protein synthesis in bright-phase dormant spores.
Collapse
|
9
|
Spona-Friedl M, Braun A, Huber C, Eisenreich W, Griebler C, Kappler A, Elsner M. Substrate-dependent CO2 fixation in heterotrophic bacteria revealed by stable isotope labelling. FEMS Microbiol Ecol 2020; 96:5828077. [DOI: 10.1093/femsec/fiaa080] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 04/30/2020] [Indexed: 11/14/2022] Open
Abstract
ABSTRACTVirtually all heterotrophs incorporate carbon dioxide by anaplerotic fixation. Little explored, however, is the interdependency of pathways and rates of CO2fixation on the concurrent usage of organic substrate(s). Potentially, this could reveal which substrates out of a pool of dissolved organic carbon are utilised by environmental microorganisms. To explore this possibility, Bacillus subtilis W23 was grown in a minimal medium with normalised amounts of either glucose, lactate or malate as only organic substrates, each together with 1 g/L NaH13CO3. Incorporation of H13CO3− was traced by elemental analysis-isotope ratio mass spectrometry of biomass and gas chromatography-mass spectrometry of protein-derived amino acids. Until the late logarithmic phase, 13C incorporation into the tricarboxylic acid cycle increased with time and occurred via [4–13C]oxaloacetate formed by carboxylation of pyruvate. The levels of 13C incorporation were highest for growth on glucose and lowest on malate. Incorporation of 13C into gluconeogenesis products was mainly detected in the lactate and malate experiment, whereas glucose down-regulated this path. A proof-of-principle study with a natural groundwater community confirmed the ability to determine incorporation from H13CO3− by natural communities leading to specific labelling patterns. This underlines the potential of the labelling approach to characterise carbon sources of heterotrophic microorganisms in their natural environments.
Collapse
Affiliation(s)
- Marina Spona-Friedl
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Alexander Braun
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Claudia Huber
- Chair of Biochemistry, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
| | - Wolfgang Eisenreich
- Chair of Biochemistry, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
| | - Christian Griebler
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
- Department of Functional and Evolutionary Ecology, Universität Wien, Althanstr. 14, A-1090 Wien, Austria
| | - Andreas Kappler
- Geomicrobiology, Eberhard-Karls-University Tuebingen, Sigwartstr. 10, 72076 Tuebingen, Germany
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
- Chair of Analytical Chemistry and Water Chemistry, Technische Universität München, Marchioninistr. 17, 81377 München, Germany
| |
Collapse
|
10
|
Halmschlag B, Hoffmann K, Hanke R, Putri SP, Fukusaki E, Büchs J, Blank LM. Comparison of Isomerase and Weimberg Pathway for γ-PGA Production From Xylose by Engineered Bacillus subtilis. Front Bioeng Biotechnol 2020; 7:476. [PMID: 32039180 PMCID: PMC6985040 DOI: 10.3389/fbioe.2019.00476] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 12/23/2019] [Indexed: 11/13/2022] Open
Abstract
The production of poly-γ-glutamic acid (γ-PGA), a biopolymer consisting of D- and L-glutamic acid monomers, currently relies on L-glutamate, or citrate as carbon substrates. Here we aimed at using plant biomass-derived substrates such as xylose. γ-PGA producing microorganisms including Bacillus subtilis natively metabolize xylose via the isomerase pathway. The Weimberg pathway, a xylose utilization pathway first described for Caulobacter crescentus, offers a carbon-efficient alternative converting xylose to 2-oxoglutarate without carbon loss. We engineered a recombinant B. subtilis strain that was able to grow on xylose with a growth rate of 0.43 h-1 using a recombinant Weimberg pathway. Although ion-pair reversed-phase LC/MS/MS metabolome analysis revealed lower concentrations of γ-PGA precursors such as 2-oxoglutarate, the γ-PGA titer was increased 6-fold compared to the native xylose isomerase strain. Further metabolome analysis indicates a metabolic bottleneck in the phosphoenolpyruvate-pyruvate-oxaloacetate node causing bi-phasic (diauxic) growth of the recombinant Weimberg strain. Flux balance analysis (FBA) of the γ-PGA producing B. subtilis indicated that a maximal theoretical γ-PGA yield is achieved on D-xylose/ D-glucose mixtures. The results of the B. subtilis strain harboring the Weimberg pathway on such D-xylose/ D-glucose mixtures demonstrate indeed resource efficient, high yield γ-PGA production from biomass-derived substrates.
Collapse
Affiliation(s)
- Birthe Halmschlag
- Institute of Applied Microbiology, Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Kyra Hoffmann
- AVT-Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - René Hanke
- AVT-Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - Sastia P Putri
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Eiichiro Fukusaki
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Jochen Büchs
- AVT-Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - Lars M Blank
- Institute of Applied Microbiology, Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
| |
Collapse
|
11
|
Measures to improve wine malolactic fermentation. Appl Microbiol Biotechnol 2019; 103:2033-2051. [DOI: 10.1007/s00253-018-09608-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 12/27/2018] [Indexed: 01/06/2023]
|
12
|
Takahashi-Íñiguez T, Barrios-Hernández J, Rodríguez-Maldonado M, Flores ME. Tricarboxylic acid cycle without malate dehydrogenase in Streptomyces coelicolor M-145. Arch Microbiol 2018; 200:1279-1286. [DOI: 10.1007/s00203-018-1541-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 06/01/2018] [Accepted: 06/16/2018] [Indexed: 11/28/2022]
|
13
|
Gu Y, Lv X, Liu Y, Li J, Du G, Chen J, Rodrigo LA, Liu L. Synthetic redesign of central carbon and redox metabolism for high yield production of N-acetylglucosamine in Bacillus subtilis. Metab Eng 2018; 51:59-69. [PMID: 30343048 DOI: 10.1016/j.ymben.2018.10.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 09/26/2018] [Accepted: 10/01/2018] [Indexed: 01/06/2023]
Abstract
One of the primary goals of microbial metabolic engineering is to achieve high titer, yield and productivity (TYP) of engineered strains. This TYP index requires optimized carbon flux toward desired molecule with minimal by-product formation. De novo redesign of central carbon and redox metabolism holds great promise to alleviate pathway bottleneck and improve carbon and energy utilization efficiency. The engineered strain, with the overexpression or deletion of multiple genes, typically can't meet the TYP index, due to overflow of central carbon and redox metabolism that compromise the final yield, despite a high titer or productivity might be achieved. To solve this challenge, we reprogramed the central carbon and redox metabolism of Bacillus subtilis and achieved high TYP production of N-acetylglucosamine. Specifically, a "push-pull-promote" approach efficiently reduced the overflown acetyl-CoA flux and eliminated byproduct formation. Four synthetic NAD(P)-independent metabolic routes were introduced to rewire the redox metabolism to minimize energy loss. Implementation of these genetic strategies led us to obtain a B. subtilis strain with superior TYP index. GlcNAc titer in shake flask was increased from 6.6 g L-1 to 24.5 g L-1, the yield was improved from 0.115 to 0.468 g GlcNAc g-1 glucose, and the productivity was increased from 0.274 to 0.437 g L-1 h-1. These titer and yield are the highest levels ever reported and, the yield reached 98% of the theoretical pathway yield (0.478 g g-1 glucose). The synthetic redesign of carbon metabolism and redox metabolism represent a novel and general metabolic engineering strategy to improve the performance of microbial cell factories.
Collapse
Affiliation(s)
- Yang Gu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Xueqin Lv
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Yanfeng Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Jian Chen
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | | | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.
| |
Collapse
|
14
|
Buffing MF, Link H, Christodoulou D, Sauer U. Capacity for instantaneous catabolism of preferred and non-preferred carbon sources in Escherichia coli and Bacillus subtilis. Sci Rep 2018; 8:11760. [PMID: 30082753 PMCID: PMC6079084 DOI: 10.1038/s41598-018-30266-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 07/26/2018] [Indexed: 02/08/2023] Open
Abstract
Making the right choice for nutrient consumption in an ever-changing environment is a key factor for evolutionary success of bacteria. Here we investigate the regulatory mechanisms that enable dynamic adaptation between non-preferred and preferred carbon sources for the model Gram-negative and -positive species Escherichia coli and Bacillus subtilis, respectively. We focus on the ability for instantaneous catabolism of a gluconeogenic carbon source upon growth on a glycolytic carbon source and vice versa. By following isotopic tracer dynamics on a 1–2 minute scale, we show that flux reversal from the preferred glucose to non-preferred pyruvate as the sole carbon source is primarily transcriptionally regulated. In the opposite direction, however, E. coli can reverse its flux instantaneously by means of allosteric regulation, whereas in B. subtilis this flux reversal is transcriptionally regulated. Upon removal of transcriptional regulation, B. subtilis assumes the ability of instantaneous glucose catabolism. Using an approach that combines quantitative metabolomics and kinetic modelling, we then identify the additionally necessary key metabolite-enzyme interactions that implement the instantaneous flux reversal in the transcriptionally deregulated B. subtilis, and validate the most relevant allosteric interactions.
Collapse
Affiliation(s)
- Marieke F Buffing
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.,Life Science Zurich PhD Program on Systems Biology, Zurich, Switzerland
| | - Hannes Link
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Dimitris Christodoulou
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.,Life Science Zurich PhD Program on Systems Biology, Zurich, Switzerland
| | - Uwe Sauer
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.
| |
Collapse
|
15
|
Rosenthal AZ, Qi Y, Hormoz S, Park J, Li SHJ, Elowitz MB. Metabolic interactions between dynamic bacterial subpopulations. eLife 2018; 7:33099. [PMID: 29809139 PMCID: PMC6025961 DOI: 10.7554/elife.33099] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 05/21/2018] [Indexed: 01/08/2023] Open
Abstract
Individual microbial species are known to occupy distinct metabolic niches within multi-species communities. However, it has remained largely unclear whether metabolic specialization can similarly occur within a clonal bacterial population. More specifically, it is not clear what functions such specialization could provide and how specialization could be coordinated dynamically. Here, we show that exponentially growing Bacillus subtilis cultures divide into distinct interacting metabolic subpopulations, including one population that produces acetate, and another population that differentially expresses metabolic genes for the production of acetoin, a pH-neutral storage molecule. These subpopulations exhibit distinct growth rates and dynamic interconversion between states. Furthermore, acetate concentration influences the relative sizes of the different subpopulations. These results show that clonal populations can use metabolic specialization to control the environment through a process of dynamic, environmentally-sensitive state-switching. The chemical reactions that occur within a living organism are collectively referred to as its metabolism. Many metabolic reactions produce byproducts that will poison the cells if they are not dealt with: fermenting bacteria, for example, release harmful organic acids and alcohols. How the bacteria respond to these toxins has been most studied at the level of entire microbial populations, meaning the activities of individual cells are effectively “averaged” together. Yet, even two bacteria with the same genes and living in the same environment can behave in different ways. This raises the question: do bacterial populations specialize into distinct subpopulations that play distinct roles when dealing with metabolic products, or do all cells in the community act in unison? Rosenthal et al. set out to answer this question for a community of Bacillus subtilis, a bacterium that is commonly studied in the laboratory and used for the industrial production of enzymes. The analysis focused on genes involved in fundamental metabolic processes, known as the TCA cycle, which the bacteria use to generate energy and build biomass. The experiments revealed that, even when all the cells are genetically identical, different Bacillus subtilis cells do indeed specialize into metabolic subpopulations with distinct growth rates. Time-lapse movies of bacteria that made fluorescent markers of different colors whenever certain metabolic genes became active showed cells switching different colors on and off, indicating that they switch between metabolic subpopulations. Further biochemical studies and measures of gene activity revealed that the different subpopulations produce and release distinct metabolic products, including toxic byproducts. Notably, the release of these metabolites by one subpopulation appeared to activate other subpopulations within the community. This example of cells specializing into unique interacting metabolic subpopulations provides insight into several fundamental issues in microbiology and beyond. It is relevant to evolutionary biologists, since the fact that fractions of the population can switch in and out of a metabolic state, instead of evolving into several inflexible specialists, may provide an evolutionary advantage in fluctuating natural environments by reducing the risk of extinction. It also has implications for industrial fermentation processes and metabolic engineering, and may help biotechnologists design more efficient ways to harness bacterial metabolism to produce useful products.
Collapse
Affiliation(s)
- Adam Z Rosenthal
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States.,Department of Applied Physics, California Institute of Technology, Pasadena, United States
| | - Yutao Qi
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States.,Department of Applied Physics, California Institute of Technology, Pasadena, United States
| | - Sahand Hormoz
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States.,Department of Applied Physics, California Institute of Technology, Pasadena, United States
| | - Jin Park
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States.,Department of Applied Physics, California Institute of Technology, Pasadena, United States
| | - Sophia Hsin-Jung Li
- Department of Molecular Biology, Princeton University, Princeton, United States
| | - Michael B Elowitz
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States.,Department of Applied Physics, California Institute of Technology, Pasadena, United States.,Howard Hughes Medical Institute, Pasadena, United States
| |
Collapse
|
16
|
Martins SJ, Medeiros FHV, Lakshmanan V, Bais HP. Impact of Seed Exudates on Growth and Biofilm Formation of Bacillus amyloliquefaciens ALB629 in Common Bean. Front Microbiol 2018; 8:2631. [PMID: 29375501 PMCID: PMC5767182 DOI: 10.3389/fmicb.2017.02631] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 12/15/2017] [Indexed: 11/22/2022] Open
Abstract
We aimed to unravel the events which favor the seed-rhizobacterium Bacillus amyloliquefaciens strain ALB629 (hereafter ALB629) interaction and which may interfere with the rhizobacterium colonization and growth on the spermosphere of common bean. Seed exudates from common bean were tested in vitro for ALB629 biofilm formation and bacterial growth. Furthermore, the performance of ALB629 on plant-related variables under drought stress was checked. Seed exudates (1 and 5% v/v) increased ALB629 biofilm formation. Additionally, the colony forming units for ALB629 increased both in culture and on the bean seed surface. The bean seed exudates up-regulated biofilm operons in ALB629 TasA and EpsD by ca. two and sixfold, respectively. The high-performance liquid chromatography (HPLC)-coupled with MS showed that malic acid is present as a major organic acid component in the seed exudates. Seeds treated with ALB629 and amended with malic acid resulted in seedlings with a higher bacterial concentration, induced plant drought tolerance, and promoted plant growth. We showed that seed exudates promote growth of ALB629 and malic acid was identified as a major organic acid component in the bean seed exudates. Our results also show that supplementation of ALB629 induced drought tolerance and growth in plants. The research pertaining to the biological significance of seed exudates in plant–microbe interaction is unexplored field and our work shows the importance of seed exudates in priming both growth and tolerance against abiotic stress.
Collapse
Affiliation(s)
- Samuel J Martins
- Department of Plant Pathology, Universidade Federal de Lavras, Lavras, Brazil.,Department of Plant and Soil Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, DE, United States
| | - Flávio H V Medeiros
- Department of Plant Pathology, Universidade Federal de Lavras, Lavras, Brazil
| | - Venkatachalam Lakshmanan
- Department of Plant and Soil Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, DE, United States
| | - Harsh P Bais
- Department of Plant and Soil Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, DE, United States
| |
Collapse
|
17
|
Transcriptomic profiles of Clostridium ljungdahlii during lithotrophic growth with syngas or H 2 and CO 2 compared to organotrophic growth with fructose. Sci Rep 2017; 7:13135. [PMID: 29030620 PMCID: PMC5640608 DOI: 10.1038/s41598-017-12712-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 09/14/2017] [Indexed: 01/13/2023] Open
Abstract
Clostridium ljungdahlii derives energy by lithotrophic and organotrophic acetogenesis. C. ljungdahlii was grown organotrophically with fructose and also lithotrophically, either with syngas - a gas mixture containing hydrogen (H2), carbon dioxide (CO2), and carbon monoxide (CO), or with H2 and CO2. Gene expression was compared quantitatively by microarrays using RNA extracted from all three conditions. Gene expression with fructose and with H2/CO2 was compared by RNA-Seq. Upregulated genes with both syngas and H2/CO2 (compared to fructose) point to the urea cycle, uptake and degradation of peptides and amino acids, response to sulfur starvation, potentially NADPH-producing pathways involving (S)-malate and ornithine, quorum sensing, sporulation, and cell wall remodeling, suggesting a global and multicellular response to lithotrophic conditions. With syngas, the upregulated (R)-lactate dehydrogenase gene represents a route of electron transfer from ferredoxin to NAD. With H2/CO2, flavodoxin and histidine biosynthesis genes were upregulated. Downregulated genes corresponded to an intracytoplasmic microcompartment for disposal of methylglyoxal, a toxic byproduct of glycolysis, as 1-propanol. Several cytoplasmic and membrane-associated redox-active protein genes were differentially regulated. The transcriptomic profiles of C. ljungdahlii in lithotrophic and organotrophic growth modes indicate large-scale physiological and metabolic differences, observations that may guide biofuel and commodity chemical production with this species.
Collapse
|
18
|
Stability of Proteins Out of Service: the GapB Case of Bacillus subtilis. J Bacteriol 2017; 199:JB.00148-17. [PMID: 28760849 DOI: 10.1128/jb.00148-17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/22/2017] [Indexed: 11/20/2022] Open
Abstract
Bacillus subtilis possesses two glyceraldehyde-3-phosphate dehydrogenases with opposite roles, the glycolytic NAD-dependent GapA and the NADP-dependent GapB enzyme, which is exclusively required during gluconeogenesis but not active under conditions promoting glycolysis. We propose that proteins that are no longer needed will be recognized and proteolyzed by Clp proteases and thereby recycled. To test this postulation, we analyzed the stability of the glycolytic enzyme GapA and the gluconeogenetic enzyme GapB in the presence and absence of glucose. It turned out that GapA remained rather stable under both glycolytic and gluconeogenetic conditions. In contrast, the gluconeogenetic enzyme GapB was degraded after a shift from malate to glucose (i.e., from gluconeogenesis to glycolysis), displaying an estimated half-life of approximately 3 h. Comparative in vivo pulse-chase labeling and immunoprecipitation experiments of the wild-type strain and isogenic mutants identified the ATP-dependent ClpCP protease as the enzyme responsible for the degradation of GapB. However, arginine protein phosphorylation, which was recently described as a general tagging mechanism for protein degradation, did not seem to play a role in GapB proteolysis, because GapB was also degraded in a mcsB mutant, lacking arginine kinase, in the same manner as in the wild type.IMPORTANCE GapB, the NADP-dependent glyceraldehyde-3-phosphosphate dehydrogenase, is essential for B. subtilis under gluconeogenetic conditions. However, after a shift to glycolytic conditions, GapB loses its physiological function within the cell and becomes susceptible to degradation, in contrast to GapA, the glycolytic NAD-dependent glyceraldehyde-3-phosphate dehydrogenase, which remains stable under glycolytic and gluconeogenetic conditions. Subsequently, GapB is proteolyzed in a ClpCP-dependent manner. According to our data, the arginine kinase McsB is not involved as adaptor protein in this process. ClpCP appears to be in charge in the removal of inoperable enzymes in B. subtilis, which is a strictly regulated process in which the precise recognition mechanism(s) remains to be identified.
Collapse
|
19
|
Genomic Analysis of Calderihabitans maritimus KKC1, a Thermophilic, Hydrogenogenic, Carboxydotrophic Bacterium Isolated from Marine Sediment. Appl Environ Microbiol 2017; 83:AEM.00832-17. [PMID: 28526793 DOI: 10.1128/aem.00832-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 05/13/2017] [Indexed: 11/20/2022] Open
Abstract
Calderihabitans maritimus KKC1 is a thermophilic, hydrogenogenic carboxydotroph isolated from a submerged marine caldera. Here, we describe the de novo sequencing and feature analysis of the C. maritimus KKC1 genome. Genome-based phylogenetic analysis confirmed that C. maritimus KKC1 was most closely related to the genus Moorella, which includes well-studied acetogenic members. Comparative genomic analysis revealed that, like Moorella, C. maritimus KKC1 retained both the CO2-reducing Wood-Ljungdahl pathway and energy-converting hydrogenase-based module activated by reduced ferredoxin, but it lacked the HydABC and NfnAB electron-bifurcating enzymes and pyruvate:ferredoxin oxidoreductase required for ferredoxin reduction for acetogenic growth. Furthermore, C. maritimus KKC1 harbored six genes encoding CooS, a catalytic subunit of the anaerobic CO dehydrogenase that can reduce ferredoxin via CO oxidation, whereas Moorella possessed only two CooS genes. Our analysis revealed that three cooS genes formed known gene clusters in other microorganisms, i.e., cooS-acetyl coenzyme A (acetyl-CoA) synthase (which contained a frameshift mutation), cooS-energy-converting hydrogenase, and cooF-cooS-FAD-NAD oxidoreductase, while the other three had novel genomic contexts. Sequence composition analysis indicated that these cooS genes likely evolved from a common ancestor. Collectively, these data suggest that C. maritimus KKC1 may be highly dependent on CO as a low-potential electron donor to directly reduce ferredoxin and may be more suited to carboxydotrophic growth compared to the acetogenic growth observed in Moorella, which show adaptation at a thermodynamic limit.IMPORTANCECalderihabitans maritimus KKC1 and members of the genus Moorella are phylogenetically related but physiologically distinct. The former is a hydrogenogenic carboxydotroph that can grow on carbon monoxide (CO) with H2 production, whereas the latter include acetogenic bacteria that grow on H2 plus CO2 with acetate production. Both species may require reduced ferredoxin as an actual "energy equivalent," but ferredoxin is a low-potential electron carrier and requires a high-energy substrate as an electron donor for reduction. Comparative genomic analysis revealed that C. maritimus KKC1 lacked specific electron-bifurcating enzymes and possessed six CO dehydrogenases, unlike Moorella species. This suggests that C. maritimus KKC1 may be more dependent on CO, a strong electron donor that can directly reduce ferredoxin via CO dehydrogenase, and may exhibit a survival strategy different from that of acetogenic Moorella, which solves the energetic barrier associated with endergonic reduction of ferredoxin with hydrogen.
Collapse
|
20
|
Durand S, Braun F, Helfer AC, Romby P, Condon C. sRNA-mediated activation of gene expression by inhibition of 5'-3' exonucleolytic mRNA degradation. eLife 2017; 6. [PMID: 28436820 PMCID: PMC5419742 DOI: 10.7554/elife.23602] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 04/23/2017] [Indexed: 12/13/2022] Open
Abstract
Post-transcriptional control by small regulatory RNA (sRNA) is critical for rapid adaptive processes. sRNAs can directly modulate mRNA degradation in Proteobacteria without interfering with translation. However, Firmicutes have a fundamentally different set of ribonucleases for mRNA degradation and whether sRNAs can regulate the activity of these enzymes is an open question. We show that Bacillus subtilis RoxS, a major trans-acting sRNA shared with Staphylococus aureus, prevents degradation of the yflS mRNA, encoding a malate transporter. In the presence of malate, RoxS transiently escapes from repression by the NADH-sensitive transcription factor Rex and binds to the extreme 5'-end of yflS mRNA. This impairs the 5'-3' exoribonuclease activity of RNase J1, increasing the half-life of the primary transcript and concomitantly enhancing ribosome binding to increase expression of the transporter. Globally, the different targets regulated by RoxS suggest that it helps readjust the cellular NAD+/NADH balance when perturbed by different stimuli.
Collapse
Affiliation(s)
- Sylvain Durand
- UMR8261 CNRS, Université Paris Diderot (Sorbonne Paris Cité), Institut de Biologie Physico-Chimique, Paris, France
| | - Frédérique Braun
- UMR8261 CNRS, Université Paris Diderot (Sorbonne Paris Cité), Institut de Biologie Physico-Chimique, Paris, France
| | - Anne-Catherine Helfer
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, Strasbourg, France
| | - Pascale Romby
- UMR8261 CNRS, Université Paris Diderot (Sorbonne Paris Cité), Institut de Biologie Physico-Chimique, Paris, France.,Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, Strasbourg, France
| | - Ciarán Condon
- UMR8261 CNRS, Université Paris Diderot (Sorbonne Paris Cité), Institut de Biologie Physico-Chimique, Paris, France
| |
Collapse
|
21
|
Saejung C, Thammaratana T. Biomass recovery during municipal wastewater treatment using photosynthetic bacteria and prospect of production of single cell protein for feedstuff. ENVIRONMENTAL TECHNOLOGY 2016; 37:3055-3061. [PMID: 27070497 DOI: 10.1080/09593330.2016.1175512] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Utilization of photosynthetic bacteria (PSB) for wastewater treatment and production of biomass for economical single cell protein production is a feasible option. In this study, Rhodopseudomonas sp. CSK01 was used for municipal wastewater treatment and the effect of initial pH, light intensity and additional carbon source was investigated. Optimum chemical oxygen demand (COD) removal and biomass production were achieved when the initial pH and light intensity were 7 and 4000 lux, respectively. The specific growth rate, biomass yield and biomass productivity were found to be 0.4/d, 3.2 g/g COD and 2.1 g/L/d, respectively, which were improved by 100%, 167% and 200% relative to the original condition. Under the optimal conditions, COD removal reached 85% and maximum biomass was 6.2 g/L accomplished within three days of cultivation. The biomass had a relatively high protein content (60.1%) consisting of all essential amino acids. The contents of histidine, lysine, phenylalanine and leucine were superior to those of the previously described PSB. Results showed that COD removal was not improved in the presence of additional carbon sources (glucose, sucrose and malic acid). The addition of malic acid significantly increased the biomass accumulation by 279% relative to the original condition, whereas COD removal was declined due to carbon catabolite repression. In this study, PSB biomass recovery and catabolite repression are proposed in municipal wastewater treatment by Rhodopseudomonas sp.
Collapse
Affiliation(s)
- Chewapat Saejung
- a Department of Microbiology, Faculty of Science , Khon Kaen University , Khon Kaen , Thailand
- b Applied Taxonomic Research Center, Faculty of Science , Khon Kaen University , Khon Kaen , Thailand
| | - Thani Thammaratana
- a Department of Microbiology, Faculty of Science , Khon Kaen University , Khon Kaen , Thailand
| |
Collapse
|
22
|
Zhang Y, Smallbone LA, diCenzo GC, Morton R, Finan TM. Loss of malic enzymes leads to metabolic imbalance and altered levels of trehalose and putrescine in the bacterium Sinorhizobium meliloti. BMC Microbiol 2016; 16:163. [PMID: 27456220 PMCID: PMC4960864 DOI: 10.1186/s12866-016-0780-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 07/15/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malic enzymes decarboxylate the tricarboxylic acid (TCA) cycle intermediate malate to the glycolytic end-product pyruvate and are well positioned to regulate metabolic flux in central carbon metabolism. Despite the wide distribution of these enzymes, their biological roles are unclear in part because the reaction catalyzed by these enzymes can be by-passed by other pathways. The N2-fixing alfalfa symbiont Sinorhizobium meliloti contains both a NAD(P)-malic enzyme (DME) and a separate NADP-malic enzyme (TME) and to help understand the role of these enzymes, we investigated growth, metabolomic, and transcriptional consequences resulting from loss of these enzymes in free-living cells. RESULTS Loss of DME, TME, or both enzymes had no effect on growth with the glycolytic substrate, glucose. In contrast, the dme mutants, but not tme, grew slowly on the gluconeogenic substrate succinate and this slow growth was further reduced upon the addition of glucose. The dme mutant strains incubated with succinate accumulated trehalose and hexose sugar phosphates, secreted malate, and relative to wild-type, these cells had moderately increased transcription of genes involved in gluconeogenesis and pathways that divert metabolites away from the TCA cycle. While tme mutant cells grew at the same rate as wild-type on succinate, they accumulated the compatible solute putrescine. CONCLUSIONS NAD(P)-malic enzyme (DME) of S. meliloti is required for efficient metabolism of succinate via the TCA cycle. In dme mutants utilizing succinate, malate accumulates and is excreted and these cells appear to increase metabolite flow via gluconeogenesis with a resulting increase in the levels of hexose-6-phosphates and trehalose. For cells utilizing succinate, TME activity alone appeared to be insufficient to produce the levels of pyruvate required for efficient TCA cycle metabolism. Putrescine was found to accumulate in tme cells growing with succinate, and whether this is related to altered levels of NADPH requires further investigation.
Collapse
Affiliation(s)
- Ye Zhang
- Department of Biology, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada.,College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Laura Anne Smallbone
- Department of Biology, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada
| | - George C diCenzo
- Department of Biology, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada
| | - Richard Morton
- Department of Biology, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada
| | - Turlough M Finan
- Department of Biology, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada.
| |
Collapse
|
23
|
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
|
24
|
Luche S, Eymard-Vernain E, Diemer H, Van Dorsselaer A, Rabilloud T, Lelong C. Zinc oxide induces the stringent response and major reorientations in the central metabolism of Bacillus subtilis. J Proteomics 2015. [PMID: 26211718 DOI: 10.1016/j.jprot.2015.07.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Microorganisms, such as bacteria, are one of the first targets of nanoparticles in the environment. In this study, we tested the effect of two nanoparticles, ZnO and TiO2, with the salt ZnSO4 as the control, on the Gram-positive bacterium Bacillus subtilis by 2D gel electrophoresis-based proteomics. Despite a significant effect on viability (LD50), TiO2 NPs had no detectable effect on the proteomic pattern, while ZnO NPs and ZnSO4 significantly modified B. subtilis metabolism. These results allowed us to conclude that the effects of ZnO observed in this work were mainly attributable to Zn dissolution in the culture media. Proteomic analysis highlighted twelve modulated proteins related to central metabolism: MetE and MccB (cysteine metabolism), OdhA, AspB, IolD, AnsB, PdhB and YtsJ (Krebs cycle) and XylA, YqjI, Drm and Tal (pentose phosphate pathway). Biochemical assays, such as free sulfhydryl, CoA-SH and malate dehydrogenase assays corroborated the observed central metabolism reorientation and showed that Zn stress induced oxidative stress, probably as a consequence of thiol chelation stress by Zn ions. The other patterns affected by ZnO and ZnSO4 were the stringent response and the general stress response. Nine proteins involved in or controlled by the stringent response showed a modified expression profile in the presence of ZnO NPs or ZnSO4: YwaC, SigH, YtxH, YtzB, TufA, RplJ, RpsB, PdhB and Mbl. An increase in the ppGpp concentration confirmed the involvement of the stringent response during a Zn stress. All these metabolic reorientations in response to Zn stress were probably the result of complex regulatory mechanisms including at least the stringent response via YwaC.
Collapse
Affiliation(s)
- Sylvie Luche
- Pro-MD team, Université Joseph Fourier, CEA Grenoble, iRTSV, Laboratoire de Chimie et Biologie des Métaux, UMR CNRS-CEA-UJF, Grenoble, France
| | - Elise Eymard-Vernain
- Pro-MD team, Université Joseph Fourier, CEA Grenoble, iRTSV, Laboratoire de Chimie et Biologie des Métaux, UMR CNRS-CEA-UJF, Grenoble, France
| | - Hélène Diemer
- Laboratoire de Spectrométrie de Masse Bio-Organique, IPHC, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg, France; CNRS, UMR7178, 67087 Strasbourg, France
| | - Alain Van Dorsselaer
- Laboratoire de Spectrométrie de Masse Bio-Organique, IPHC, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg, France; CNRS, UMR7178, 67087 Strasbourg, France
| | - Thierry Rabilloud
- Pro-MD team, UMR CNRS 5249, Laboratoire de Chimie et Biologie des Métaux, UMR CNRS-CEA-UJF, Grenoble, France
| | - Cécile Lelong
- Pro-MD team, Université Joseph Fourier, CEA Grenoble, iRTSV, Laboratoire de Chimie et Biologie des Métaux, UMR CNRS-CEA-UJF, Grenoble, France.
| |
Collapse
|
25
|
The molecular timeline of a reviving bacterial spore. Mol Cell 2015; 57:695-707. [PMID: 25661487 PMCID: PMC4339302 DOI: 10.1016/j.molcel.2014.12.019] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 12/01/2014] [Accepted: 12/12/2014] [Indexed: 01/01/2023]
Abstract
The bacterial spore can rapidly convert from a dormant to a fully active cell. Here we study this remarkable cellular transition in Bacillus subtilis and reveal the identity of the newly synthesized proteins throughout spore revival. Our analysis uncovers a highly ordered developmental program that correlates with the spore morphological changes and reveals the spatial and temporal molecular events fundamental to reconstruct a cell. As opposed to current knowledge, we found that translation takes place during the earliest revival event, termed germination, a process hitherto considered to occur without the need for any macromolecule synthesis. Furthermore, we demonstrate that translation is required for execution of germination and relies on the bona fide translational factors RpmE and Tig. Our study sheds light on the spore revival process and on the vital building blocks underlying cellular awakening, thereby paving the way for designing new antimicrobial agents to eradicate spore-forming pathogens. We reveal the identity of the newly synthesized proteins throughout spore revival We define the timeline of molecular events occurring during spore revival Protein synthesis occurs during germination and is essential for its execution RpmE and Tig are required for protein synthesis during germination
Collapse
|
26
|
Saigo M, Golic A, Alvarez CE, Andreo CS, Hogenhout SA, Mussi MA, Drincovich MF. Metabolic regulation of phytoplasma malic enzyme and phosphotransacetylase supports the use of malate as an energy source in these plant pathogens. MICROBIOLOGY-SGM 2014; 160:2794-2806. [PMID: 25294105 DOI: 10.1099/mic.0.083469-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Phytoplasmas ('Candidatus Phytoplasma') are insect-vectored plant pathogens. The genomes of these bacteria are small with limited metabolic capacities making them dependent on their plant and insect hosts for survival. In contrast to mycoplasmas and other relatives in the class Mollicutes, phytoplasmas encode genes for malate transporters and malic enzyme (ME) for conversion of malate into pyruvate. It was hypothesized that malate is probably a major energy source for phytoplasmas as these bacteria are limited in the uptake and processing of carbohydrates. In this study, we investigated the metabolic capabilities of 'Candidatus (Ca.) phytoplasma' aster yellows witches'-broom (AYWB) malic enzyme (ME). We found that AYWB-ME has malate oxidative decarboxylation activity, being able to convert malate to pyruvate and CO2 with the reduction of either NAD or NADP, and displays distinctive kinetic mechanisms depending on the relative concentration of the substrates. AYWB-ME activity was strictly modulated by the ATP/ADP ratio, a feature which has not been found in other ME isoforms characterized to date. In addition, we found that the 'Ca. Phytoplasma' AYWB PduL-like enzyme (AYWB-PduL) harbours phosphotransacetylase activity, being able to convert acetyl-CoA to acetyl phosphate downstream of pyruvate. ATP also inhibited AYWB-PduL activity, as with AYWB-ME, and the product of the reaction catalysed by AYWB-PduL, acetyl phosphate, stimulated AYWB-ME activity. Overall, our data indicate that AYWB-ME and AYWB-PduL activities are finely coordinated by common metabolic signals, like ATP/ADP ratios and acetyl phosphate, which support their participation in energy (ATP) and reducing power [NAD(P)H] generation from malate in phytoplasmas.
Collapse
Affiliation(s)
- Mariana Saigo
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI- CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000 Rosario, Argentina
| | - Adrián Golic
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI- CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000 Rosario, Argentina
| | - Clarisa E Alvarez
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI- CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000 Rosario, Argentina
| | - Carlos S Andreo
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI- CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000 Rosario, Argentina
| | - Saskia A Hogenhout
- Department of Cell and Developmental Biology, The John Innes Centre, Norwich NR4 7UH, UK
| | - María A Mussi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI- CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000 Rosario, Argentina
| | - María F Drincovich
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI- CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000 Rosario, Argentina
| |
Collapse
|
27
|
Vadlakonda L, Reddy VDK, Pasupuleti M, Reddanna P. The Pasteur's Dictum: Nitrogen Promotes Growth and Oxygen Reduces the Need for Sugar. Front Oncol 2014; 4:51. [PMID: 24672772 PMCID: PMC3956120 DOI: 10.3389/fonc.2014.00051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Accepted: 03/03/2014] [Indexed: 01/24/2023] Open
Affiliation(s)
| | - V D K Reddy
- Department of Animal Sciences, School of Life Sciences, University of Hyderabad , Hyderabad , India
| | - Mukesh Pasupuleti
- SRM Research Institute, Sri Ramaswamy Memorial University , Chennai , India
| | - Pallu Reddanna
- Department of Animal Sciences, School of Life Sciences, University of Hyderabad , Hyderabad , India ; National Institute of Animal Biotechnology , Hyderabad , India
| |
Collapse
|