| Title |
Bacterial Structure and Characterization of Plant Growth Promoting and Oil Degrading Bacteria from the Rhizospheres of Mangrove Plants |
| Author |
Flávia Lima do Carmo1, Henrique Fragoso dos Santos1, Edir Ferreira Martins1, Jan Dirk van Elsas2, Alexandre Soares Rosado1, and Raquel Silva Peixoto1* |
| Address |
1Departamento de Microbiologia Geral, Instituto de Microbiologia Professor Paulo de Góes/UFRJ, University of Groningen, Rio de Janeiro 21941-902, Brazil, 2Department of Microbial Ecology, University of Groningen, Rio de Janeiro 21941-902, Brazil |
| Bibliography |
Journal of Microbiology, 49(4),535-543, 2011,
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| DOI |
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| Key Words |
bacterial structure, mangroves, oil-degrading rhizobacteria, PGPR |
| Abstract |
Most oil from oceanic spills converges on coastal ecosystems, such as mangrove forests, which are threatened with worldwide disappearance. Particular bacteria that inhabit the rhizosphere of local plant species can stimulate plant development through various mechanisms; it would be advantageous if these would also be capable of degrading oil. Such bacteria may be important in the preservation or recuperation of mangrove forests impacted by oil spills. This study aimed to compare the bacterial structure, isolate and evaluate bacteria able to degrade oil and stimulate plant growth, from the rhizospheres of three mangrove plant species. These features are particularly important taking into account recent policies for mangrove bioremediation, implying that oil degradation as well as plant maintenance and health are key targets. Fifty-seven morphotypes were isolated from the mangrove rhizospheres on Bushnell-Haas (BH) medium supplemented with oil as the sole carbon source and tested for plant growth promotion. Of this strains, 60% potentially fixed nitrogen, 16% showed antimicrobial activity, 84% produced siderophores, 51% had the capacity to solubilize phosphate, and 33% produced the indole acetic acid hormone. Using gas chromatography, we evaluated the oil-degrading potential of ten selected strains that had different morphologies and showed Plant Growth Promoting Rhizobacteria (PGPR) features. The ten tested strains showed a promising degradation profile for at least one compound present in the oil. Among degrader strains, 46% had promising PGPR potential, having at least three of the above capacities. These strains might be used as a consortium, allowing the concomitant degradation of oil and stimulation of mangrove plant survival and maintenance. |
