Herbaspirillum canariense sp. nov., Herbaspirillum aurantiacum sp. nov. and Herbaspirillum soli sp. nov., isolated from volcanic mountain soil, and emended description of the genus Herbaspirillum

Three Gram-negative, motile and slightly curved rod-shaped bacteria, strains SUEMI03T, SUEMI08T and SUEMI10T, were isolated from an old volcanic mountain soil on Tenerife (Canary Islands). The three strains were related phylogenetically to Herbaspirillum seropedicae. 16S rRNA gene sequence similarity was 99.2-99.6 % among strains SUEMI03T, SUEMI08T and SUEMI10T, which presented 97.5, 97.8 and 97.7 % identity, respectively, with respect to H. seropedicae DSM 6445T. The three strains grew optimally in TSB at 28 °C and contained summed features 3 (C16: 1ω6c and/or C16: 1ω7c) and 8 (C18: 1ω6c and/or C18: 1ω7c) and C16: 0 as major cellular fatty acids. The DNA G+C contents of strains SUEMI03T, SUEMI08T and SUEMI10T were 61.6, 60.4 and 61.9 mol%, respectively. Strains SUEMI03T, SUEMI08T and SUEMI10T presented less than 60 % interstrain DNA relatedness and less than 30 % relatedness with respect to H. seropedicae DSM 6445T. In spite of their common geographical origin, the three strains isolated in this study presented several phenotypic differences, presenting phenotypic profiles highly divergent from that of H. seropedicae. Therefore, we propose that the strains isolated in this study represent three novel species of the genus Herbaspirillum, named Herbaspirillum canariense sp. nov. (type strain SUEMI03T = LMG 26151T = CECT 7838T), Herbaspirillum aurantiacum sp. nov. (type strain SUEMI08T = LMG 26150T = CECT 7839T) and Herbaspirillum soli sp. nov. (type strain SUEMI10T = LMG 26149T = CECT 7840T). © 2012 IUMS.