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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...

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Autores principales: Lüddeke, Frauke, Dikfidan, Aytac, Harder, Jens
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2012
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.
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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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