A Shuttle-Vector System Allows Heterologous Gene Expression in the Thermophilic Methanogen Methanothermobacter thermautotrophicus ΔH
ABSTRACT Thermophilic Methanothermobacter spp. are used as model microbes to study the physiology and biochemistry of the conversion of molecular hydrogen and carbon dioxide into methane (i.e., hydrogenotrophic methanogenesis). Yet, a genetic system for these model microbes was missing despite inten...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
American Society for Microbiology
2021-12-01
|
| Series: | mBio |
| Subjects: | |
| Online Access: | https://journals.asm.org/doi/10.1128/mBio.02766-21 |
| _version_ | 1818941901701644288 |
|---|---|
| author | Christian Fink Sebastian Beblawy Andreas M. Enkerlin Lucas Mühling Largus T. Angenent Bastian Molitor |
| author_facet | Christian Fink Sebastian Beblawy Andreas M. Enkerlin Lucas Mühling Largus T. Angenent Bastian Molitor |
| author_sort | Christian Fink |
| collection | DOAJ |
| description | ABSTRACT Thermophilic Methanothermobacter spp. are used as model microbes to study the physiology and biochemistry of the conversion of molecular hydrogen and carbon dioxide into methane (i.e., hydrogenotrophic methanogenesis). Yet, a genetic system for these model microbes was missing despite intensive work for four decades. Here, we report the successful implementation of genetic tools for Methanothermobacter thermautotrophicus ΔH. We developed shuttle vectors that replicated in Escherichia coli and M. thermautotrophicus ΔH. For M. thermautotrophicus ΔH, a thermostable neomycin resistance cassette served as the selectable marker for positive selection with neomycin, and the cryptic plasmid pME2001 from Methanothermobacter marburgensis served as the replicon. The shuttle-vector DNA was transferred from E. coli into M. thermautotrophicus ΔH via interdomain conjugation. After the successful validation of DNA transfer and positive selection in M. thermautotrophicus ΔH, we demonstrated heterologous gene expression of a thermostable β-galactosidase-encoding gene (bgaB) from Geobacillus stearothermophilus under the expression control of four distinct synthetic and native promoters. In quantitative in-vitro enzyme activity assay, we found significantly different β-galactosidase activity with these distinct promoters. With a formate dehydrogenase operon-encoding shuttle vector, we allowed growth of M. thermautotrophicus ΔH on formate as the sole growth substrate, while this was not possible for the empty-vector control. IMPORTANCE The world economies are facing permanently increasing energy demands. At the same time, carbon emissions from fossil sources need to be circumvented to minimize harmful effects from climate change. The power-to-gas platform is utilized to store renewable electric power and decarbonize the natural gas grid. The microbe Methanothermobacter thermautotrophicus is already applied as the industrial biocatalyst for the biological methanation step in large-scale power-to-gas processes. To improve the biocatalyst in a targeted fashion, genetic engineering is required. With our shuttle-vector system for heterologous gene expression in M. thermautotrophicus, we set the cornerstone to engineer the microbe for optimized methane production but also for production of high-value platform chemicals in power-to-x processes. |
| first_indexed | 2024-12-20T07:02:54Z |
| format | Article |
| id | doaj.art-7fb1422ba9e045da889aab6951128da9 |
| institution | Directory Open Access Journal |
| issn | 2150-7511 |
| language | English |
| last_indexed | 2024-12-20T07:02:54Z |
| publishDate | 2021-12-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | mBio |
| spelling | doaj.art-7fb1422ba9e045da889aab6951128da92022-12-21T19:49:09ZengAmerican Society for MicrobiologymBio2150-75112021-12-0112610.1128/mBio.02766-21A Shuttle-Vector System Allows Heterologous Gene Expression in the Thermophilic Methanogen Methanothermobacter thermautotrophicus ΔHChristian Fink0Sebastian Beblawy1Andreas M. Enkerlin2Lucas Mühling3Largus T. Angenent4Bastian Molitor5Environmental Biotechnology Group, University of Tübingen, Tübingen, GermanyEnvironmental Biotechnology Group, University of Tübingen, Tübingen, GermanyEnvironmental Biotechnology Group, University of Tübingen, Tübingen, GermanyEnvironmental Biotechnology Group, University of Tübingen, Tübingen, GermanyEnvironmental Biotechnology Group, University of Tübingen, Tübingen, GermanyEnvironmental Biotechnology Group, University of Tübingen, Tübingen, GermanyABSTRACT Thermophilic Methanothermobacter spp. are used as model microbes to study the physiology and biochemistry of the conversion of molecular hydrogen and carbon dioxide into methane (i.e., hydrogenotrophic methanogenesis). Yet, a genetic system for these model microbes was missing despite intensive work for four decades. Here, we report the successful implementation of genetic tools for Methanothermobacter thermautotrophicus ΔH. We developed shuttle vectors that replicated in Escherichia coli and M. thermautotrophicus ΔH. For M. thermautotrophicus ΔH, a thermostable neomycin resistance cassette served as the selectable marker for positive selection with neomycin, and the cryptic plasmid pME2001 from Methanothermobacter marburgensis served as the replicon. The shuttle-vector DNA was transferred from E. coli into M. thermautotrophicus ΔH via interdomain conjugation. After the successful validation of DNA transfer and positive selection in M. thermautotrophicus ΔH, we demonstrated heterologous gene expression of a thermostable β-galactosidase-encoding gene (bgaB) from Geobacillus stearothermophilus under the expression control of four distinct synthetic and native promoters. In quantitative in-vitro enzyme activity assay, we found significantly different β-galactosidase activity with these distinct promoters. With a formate dehydrogenase operon-encoding shuttle vector, we allowed growth of M. thermautotrophicus ΔH on formate as the sole growth substrate, while this was not possible for the empty-vector control. IMPORTANCE The world economies are facing permanently increasing energy demands. At the same time, carbon emissions from fossil sources need to be circumvented to minimize harmful effects from climate change. The power-to-gas platform is utilized to store renewable electric power and decarbonize the natural gas grid. The microbe Methanothermobacter thermautotrophicus is already applied as the industrial biocatalyst for the biological methanation step in large-scale power-to-gas processes. To improve the biocatalyst in a targeted fashion, genetic engineering is required. With our shuttle-vector system for heterologous gene expression in M. thermautotrophicus, we set the cornerstone to engineer the microbe for optimized methane production but also for production of high-value platform chemicals in power-to-x processes.https://journals.asm.org/doi/10.1128/mBio.02766-21ArchaeageneticsMethanothermobactershuttle vectorβ-galactosidaseformate |
| spellingShingle | Christian Fink Sebastian Beblawy Andreas M. Enkerlin Lucas Mühling Largus T. Angenent Bastian Molitor A Shuttle-Vector System Allows Heterologous Gene Expression in the Thermophilic Methanogen Methanothermobacter thermautotrophicus ΔH mBio Archaea genetics Methanothermobacter shuttle vector β-galactosidase formate |
| title | A Shuttle-Vector System Allows Heterologous Gene Expression in the Thermophilic Methanogen Methanothermobacter thermautotrophicus ΔH |
| title_full | A Shuttle-Vector System Allows Heterologous Gene Expression in the Thermophilic Methanogen Methanothermobacter thermautotrophicus ΔH |
| title_fullStr | A Shuttle-Vector System Allows Heterologous Gene Expression in the Thermophilic Methanogen Methanothermobacter thermautotrophicus ΔH |
| title_full_unstemmed | A Shuttle-Vector System Allows Heterologous Gene Expression in the Thermophilic Methanogen Methanothermobacter thermautotrophicus ΔH |
| title_short | A Shuttle-Vector System Allows Heterologous Gene Expression in the Thermophilic Methanogen Methanothermobacter thermautotrophicus ΔH |
| title_sort | shuttle vector system allows heterologous gene expression in the thermophilic methanogen methanothermobacter thermautotrophicus δh |
| topic | Archaea genetics Methanothermobacter shuttle vector β-galactosidase formate |
| url | https://journals.asm.org/doi/10.1128/mBio.02766-21 |
| work_keys_str_mv | AT christianfink ashuttlevectorsystemallowsheterologousgeneexpressioninthethermophilicmethanogenmethanothermobacterthermautotrophicusdh AT sebastianbeblawy ashuttlevectorsystemallowsheterologousgeneexpressioninthethermophilicmethanogenmethanothermobacterthermautotrophicusdh AT andreasmenkerlin ashuttlevectorsystemallowsheterologousgeneexpressioninthethermophilicmethanogenmethanothermobacterthermautotrophicusdh AT lucasmuhling ashuttlevectorsystemallowsheterologousgeneexpressioninthethermophilicmethanogenmethanothermobacterthermautotrophicusdh AT largustangenent ashuttlevectorsystemallowsheterologousgeneexpressioninthethermophilicmethanogenmethanothermobacterthermautotrophicusdh AT bastianmolitor ashuttlevectorsystemallowsheterologousgeneexpressioninthethermophilicmethanogenmethanothermobacterthermautotrophicusdh AT christianfink shuttlevectorsystemallowsheterologousgeneexpressioninthethermophilicmethanogenmethanothermobacterthermautotrophicusdh AT sebastianbeblawy shuttlevectorsystemallowsheterologousgeneexpressioninthethermophilicmethanogenmethanothermobacterthermautotrophicusdh AT andreasmenkerlin shuttlevectorsystemallowsheterologousgeneexpressioninthethermophilicmethanogenmethanothermobacterthermautotrophicusdh AT lucasmuhling shuttlevectorsystemallowsheterologousgeneexpressioninthethermophilicmethanogenmethanothermobacterthermautotrophicusdh AT largustangenent shuttlevectorsystemallowsheterologousgeneexpressioninthethermophilicmethanogenmethanothermobacterthermautotrophicusdh AT bastianmolitor shuttlevectorsystemallowsheterologousgeneexpressioninthethermophilicmethanogenmethanothermobacterthermautotrophicusdh |