Chemoheterotrophic Growth of the Cyanobacterium Anabaena sp. Strain PCC 7120 Dependent on a Functional Cytochrome c Oxidase
| Autor: | Ronald Stebegg, Georg Schmetterer, Markus Mikulic, Bernhard Wurzinger |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Cyanobacteria
Monosaccharide Transport Proteins Fructose Microbiology Electron Transport Complex IV chemistry.chemical_compound Bacterial Proteins Cytochrome c oxidase Molecular Biology Sequence Deletion chemistry.chemical_classification biology Anabaena Synechocystis Heterotrophic Processes Gene Expression Regulation Bacterial Articles biology.organism_classification Phototrophic Processes Glucose Phenotype Enzyme chemistry Biochemistry Nitrogen fixation biology.protein bacteria |
| Zdroj: | Journal of Bacteriology. 194:4601-4607 |
| ISSN: | 0021-9193 |
| DOI: | 10.1128/jb.00687-12 |
| Popis: | Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium commonly used as a model organism for studying cyanobacterial cell differentiation and nitrogen fixation. For many decades, this cyanobacterium was considered an obligate photo-lithoautotroph. We now discovered that this strain is also capable of mixotrophic, photo-organoheterotrophic, and chemo-organoheterotrophic growth if high concentrations of fructose (at least 50 mM and up to 200 mM) are supplied. Glucose, a substrate used by some facultatively organoheterotrophic cyanobacteria, is not effective in Anabaena sp. PCC 7120. The gtr gene from Synechocystis sp. PCC 6803 encoding a glucose carrier was introduced into Anabaena sp. PCC 7120. Surprisingly, the new strain containing the gtr gene did not grow on glucose but was very sensitive to glucose, with a 5 mM concentration being lethal, whereas the wild-type strain tolerated 200 mM glucose. The Anabaena sp. PCC 7120 strain containing gtr can grow mixotrophically and photo-organoheterotrophically, but not chemo-organoheterotrophically with fructose. Anabaena sp. PCC 7120 contains five respiratory chains ending in five different respiratory terminal oxidases. One of these enzymes is a mitochondrial-type cytochrome c oxidase. As in almost all cyanobacteria, this enzyme is encoded by three adjacent genes called coxBAC1. When this locus was disrupted, the cells lost the capability for chemo-organoheterotrophic growth. |
| Databáze: | OpenAIRE |
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