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 Sphingomonas 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(18:1)ω7c/C(18:1)ω6c, C(16:1)ω7c/C(16:1)ω6c, C(14:0) 2OH and C(16:0). Comparison of 16S rRNA gene sequences revealed that the closest type strains to R4DWN(T) are Sphingomonas fennica, Sphingomonas formosensis, Sphingomonas prati, Sphingomonas montana and Sphingomonas oleivorans 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 Sphingomonas for which the name Sphingomonas solaris sp. nov. is proposed with the type strain R4DWN(T) (=CECT 9811(T)=LMG 31344(T)).