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Physiology of deletion mutants in the anaerobic β-myrcene degradation pathway in Castellaniella defragrans
BACKGROUND: Monoterpenes present a large and versatile group of unsaturated hydrocarbons of plant origin with widespread use in the fragrance as well as food industry. The anaerobic β-myrcene degradation pathway in Castellaniella defragrans strain 65Phen differs from well known aerobic, monooxygenas...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2012
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3490891/ https://www.ncbi.nlm.nih.gov/pubmed/22947208 http://dx.doi.org/10.1186/1471-2180-12-192 |
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author | Lüddeke, Frauke Dikfidan, Aytac Harder, Jens |
author_facet | Lüddeke, Frauke Dikfidan, Aytac Harder, Jens |
author_sort | Lüddeke, Frauke |
collection | PubMed |
description | BACKGROUND: Monoterpenes present a large and versatile group of unsaturated hydrocarbons of plant origin with widespread use in the fragrance as well as food industry. The anaerobic β-myrcene degradation pathway in Castellaniella defragrans strain 65Phen differs from well known aerobic, monooxygenase-containing pathways. The initial enzyme linalool dehydratase-isomerase ldi/LDI catalyzes the hydration of β-myrcene to (S)-(+)-linalool and its isomerization to geraniol. A high-affinity geraniol dehydrogenase geoA/GeDH and a geranial dehydrogenase geoB/GaDH contribute to the formation of geranic acid. A genetic system was for the first time applied for the betaproteobacterium to prove in vivo the relevance of the linalool dehydratase-isomerase and the geraniol dehydrogenase. In-frame deletion cassettes were introduced by conjugation and two homologous recombination events. RESULTS: Polar effects were absent in the in-frame deletion mutants C. defragrans Δldi and C. defragrans ΔgeoA. The physiological characterization of the strains demonstrated a requirement of the linalool dehydratase-isomerase for growth on acyclic monoterpenes, but not on cyclic monoterpenes. The deletion of geoA resulted in a phenotype with hampered growth rate on monoterpenes as sole carbon and energy source as well as reduced biomass yields. Enzyme assays revealed the presence of a second geraniol dehydrogenase. The deletion mutants were in trans complemented with the broad-host range expression vector pBBR1MCS-4ldi and pBBR1MCS-2geoA, restoring in both cases the wild type phenotype. CONCLUSIONS: In-frame deletion mutants of genes in the anaerobic β-myrcene degradation revealed novel insights in the in vivo function. The deletion of a high-affinity geraniol dehydrogenase hampered, but did not preclude growth on monoterpenes. A second geraniol dehydrogenase activity was present that contributes to the β-myrcene degradation pathway. Growth on cyclic monoterpenes independent of the initial enzyme LDI suggests the presence of a second enzyme system activating unsaturated hydrocarbons. |
format | Online Article Text |
id | pubmed-3490891 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-34908912012-11-07 Physiology of deletion mutants in the anaerobic β-myrcene degradation pathway in Castellaniella defragrans Lüddeke, Frauke Dikfidan, Aytac Harder, Jens BMC Microbiol Research Article BACKGROUND: Monoterpenes present a large and versatile group of unsaturated hydrocarbons of plant origin with widespread use in the fragrance as well as food industry. The anaerobic β-myrcene degradation pathway in Castellaniella defragrans strain 65Phen differs from well known aerobic, monooxygenase-containing pathways. The initial enzyme linalool dehydratase-isomerase ldi/LDI catalyzes the hydration of β-myrcene to (S)-(+)-linalool and its isomerization to geraniol. A high-affinity geraniol dehydrogenase geoA/GeDH and a geranial dehydrogenase geoB/GaDH contribute to the formation of geranic acid. A genetic system was for the first time applied for the betaproteobacterium to prove in vivo the relevance of the linalool dehydratase-isomerase and the geraniol dehydrogenase. In-frame deletion cassettes were introduced by conjugation and two homologous recombination events. RESULTS: Polar effects were absent in the in-frame deletion mutants C. defragrans Δldi and C. defragrans ΔgeoA. The physiological characterization of the strains demonstrated a requirement of the linalool dehydratase-isomerase for growth on acyclic monoterpenes, but not on cyclic monoterpenes. The deletion of geoA resulted in a phenotype with hampered growth rate on monoterpenes as sole carbon and energy source as well as reduced biomass yields. Enzyme assays revealed the presence of a second geraniol dehydrogenase. The deletion mutants were in trans complemented with the broad-host range expression vector pBBR1MCS-4ldi and pBBR1MCS-2geoA, restoring in both cases the wild type phenotype. CONCLUSIONS: In-frame deletion mutants of genes in the anaerobic β-myrcene degradation revealed novel insights in the in vivo function. The deletion of a high-affinity geraniol dehydrogenase hampered, but did not preclude growth on monoterpenes. A second geraniol dehydrogenase activity was present that contributes to the β-myrcene degradation pathway. Growth on cyclic monoterpenes independent of the initial enzyme LDI suggests the presence of a second enzyme system activating unsaturated hydrocarbons. BioMed Central 2012-09-04 /pmc/articles/PMC3490891/ /pubmed/22947208 http://dx.doi.org/10.1186/1471-2180-12-192 Text en Copyright ©2012 Lüddeke et al.; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Article Lüddeke, Frauke Dikfidan, Aytac Harder, Jens Physiology of deletion mutants in the anaerobic β-myrcene degradation pathway in Castellaniella defragrans |
title | Physiology of deletion mutants in the anaerobic β-myrcene degradation pathway in Castellaniella defragrans |
title_full | Physiology of deletion mutants in the anaerobic β-myrcene degradation pathway in Castellaniella defragrans |
title_fullStr | Physiology of deletion mutants in the anaerobic β-myrcene degradation pathway in Castellaniella defragrans |
title_full_unstemmed | Physiology of deletion mutants in the anaerobic β-myrcene degradation pathway in Castellaniella defragrans |
title_short | Physiology of deletion mutants in the anaerobic β-myrcene degradation pathway in Castellaniella defragrans |
title_sort | physiology of deletion mutants in the anaerobic β-myrcene degradation pathway in castellaniella defragrans |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3490891/ https://www.ncbi.nlm.nih.gov/pubmed/22947208 http://dx.doi.org/10.1186/1471-2180-12-192 |
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