Burkholderia novacaledonica sp. nov. and B. ultramafica sp. nov. isolated from roots of Costularia spp. pioneer plants of ultramaficsoils in New Caledonia [Plus corrigenda]

2016

Article référencé dans le Web of Science WOS:000375889500001

Guentas L., Gensous S., Cavaloc Y., Ducousso M, Hamir A., Georges de Ledenon B. de, Moulin Lionel, Jourand Philippe

Systematic and Applied Microbiology, 2016, 39 (3), p. 151-159 [+ corrigenda vol.30, no 5, p. 359 et 2019, vol. 42, p. 422] ISSN 0723-2020

tThe taxonomic status of eleven rhizospheric bacterial strains belonging to the genus Burkholderia andisolated from roots of Costularia (Cyperaceae), tropical herbaceous pioneer plants growing on ultramaficsoils in New Caledonia, was investigated using a polyphasic taxonomic approach. The genetic analyses(16S rRNA genes, gyrB, recA, nreB and cnr) confirmed that all strains are Burkholderia and cluster into twoseparated groups. The DNA hybridization results showed low relatedness values to the closest relativesBurkholderia species. The phenotypic analyses confirmed that the two groups of strains could be differ-entiated from each other and from other known Burkholderia species. This polyphasic study revealedthat these two groups of strains represent each a novel species of Burkholderia, for which the namesBurkholderia novacaledonica sp. nov. (type strain STM10272T= LMG28615T= CIP110887T) and B. ultra-mafica sp. nov. (type strain STM10279T= LMG28614T= CIP110886T) are proposed, respectively. Thesestrains of Burkholderia presented specific ecological traits such as the tolerance to the extreme edaphicconstraints of ultramafic soils: they grew at pH between 4 and 8 and tolerate the strong unbalancedCa/Mg ratio (1/19) and the high concentrations of heavy metals i.e. Co, Cr, Mn and Ni. Noteworthy B.ultramafica tolerated nickel until 10 mM and B. novacaledonica up to 5 mM. The presence of the nickel(nreB) and cobalt/nickel (cnr) resistance determinants encoding for protein involved in metal tolerancewas found in all strains of both groups. Moreover, most of the strains were able to produce plant growthpromoting molecules (ACC, IAA, NH3and siderophores). Such ecological traits suggest that these newspecies of Burkholderia might be environmentally adaptable plant-associated bacteria and beneficialto plants.

Pédologie [068] ; Biotechnologies [084]

Fonds IRD [F B010065744]

fdi:010065744