Sphingomonas solaris sp. nov., isolated from a solar panel in Boston, Massachusetts

Abstract

Solar panel surfaces, although subjected to a range of extreme environmental conditions, are inhabited by a diverse microbial community adapted to solar radiation, desiccation and temperature fluctuations. This is the first time a new bacterial species has been isolated from this environment. Strain R4DWN^T belongs to the genus <i>Sphingomonas</i> and was isolated from a solar panel surface in Boston, MA, USA. Strain R4DWN^T is a Gram-negative, non-motile and rod-shaped bacteria that tested positive for oxidase and catalase and forms round-shaped, shiny and orange-coloured colonies. It is mesophilic, neutrophilic and non-halophilic, and presents a more stenotrophic metabolism than its closest neighbours. The major fatty acids in this strain are C_18:1ω7<i>c</i>/C_18:1ω6<i>c</i>, C_16:1ω7<i>c</i>/C_16:1ω6<i>c</i>, C_14:0 2OH and C_16:0. Comparison of 16S rRNA gene sequences revealed that the closest type strains to R4DWN^T are <i>Sphingomonas fennica</i>, <i>Sphingomonas formosensis</i>, <i>Sphingomonas prati</i>, <i>Sphingomonas montana</i> and <i>Sphingomonas oleivorans</i> with 96.3, 96.1, 96.0, 95.9 and 95.7 % pairwise similarity, respectively. The genomic G+C content of R4DWN^T is 67.9 mol%. Based on these characteristics, strain R4DWN^T represents a novel species of the genus <i>Sphingomonas</i> for which the name <i>Sphingomonas solaris</i> sp. nov. is proposed with the type strain R4DWN^T (=CECT 9811^T=LMG 31344^T).