Characterization of Methylobacterium strains isolated from the phyllosphere and description of Methylobacterium longum sp. nov

Abstract

Methylobacterium strains are abundantly found in the phyllosphere of plants. Morphological, physiological and chemotaxonomical properties of 12 previously isolated strains were analyzed in order to obtain a more detailed overview of the characteristics of phyllosphere colonizing Methylobacterium strains. All strains showed the typical properties of the genus Methylobacterium, including pink pigmentation, facultative methylotrophy, a fatty acid profile dominated by C18:1 ω7c, and a high G+C content of 65 mol % or more. However, some strains showed only weak growth on methanol and pigmentation varied from pale pink to red. Strains grew best under mesophilic, neutrophilic conditions and low salt (≤1%) concentrations, but variation was seen with respect to the temperature and pH range under which growth occurred. Likewise, differences were seen with respect to carbon source utilization. Some strains were versatile and utilized diverse organic acids, amino acids and sugars, while others could only metabolize a restricted number of organic acids. The strains that were most distinct from existing type strains based on 16S rRNA gene sequence analysis were selected for DNA-DNA hybridization experiments to analyze whether they are sufficiently different at the genomic level from existing type strains to justify their classification as new species. This resulted in the delineation of strain 440 and its description as Methylobacterium longum sp. nov. strain 440 (=DSM 23933(T) = CECT 7806(T)). A main characteristic of this species is the formation of relatively long rods compared to other Methylobacterium species.

Methylobacterium pseudosasicola sp. nov. and Methylobacterium phyllostachyos sp. nov., isolated from bamboo leaf surfaces

“…Both strains had C 18:1 v7c as the major fatty acid. These were consistent with the major fatty acids of M. T (Kang et al, 2007;Madhaiyan et al, 2007a;Kato et al, 2008;Weon et al, 2008;Madhaiyan et al, 2009;Madhaiyan et al, 2012;Knief et al, 2012); however, strains BL36…”

Isolation and Characterization of Phyllospheric Methylotrophic Bacteria of Paddy from Middle Gujarat, India

“…This might be due to the proline which acts as predominant compatible solute independent of constant higher osmolality. Similar types of results were obtained by Knief et al, (2010).…”

Methylobacteria isolated from bryophytes and the 2-fold description of the same microbial species

“…As detailed elsewhere, 4,7,8 and corroborated by Tani et al, 3 M. funariae is a bryophyte-associated prokaryotic microbe that may also inhabit gametophytes of other cryptogamic plants, such as ferns. Based on our studies and those of others 13 it has been concluded that methylobacteria are methanol-consuming phytosymbionts. However, in a recent study it was shown that MeOH, which is the second most abundant organic compound released via the stomata by green leaves, is produced by the plant cells independent of light at approximately the same rate.…”