Sphingopyxis italica sp. nov., isolated from Roman catacombs.

A Gram-stain-negative, aerobic, motile, rod-shaped bacterium, strain SC13E-S71(T), was isolated from tuff, volcanic rock, where the Roman catacombs of Saint Callixtus in Rome, Italy, was excavated. Analysis of 16S rRNA gene sequences revealed that strain SC13E-S71(T) belongs to the genus Sphingopyxis, and that it shows the greatest sequence similarity with Sphingopyxis chilensis DSM 14889(T) (98.72 %), Sphingopyxis taejonensis DSM 15583(T) (98.65 %), Sphingopyxis ginsengisoli LMG 23390(T) (98.16 %), Sphingopyxis panaciterrae KCTC 12580(T) (98.09 %), Sphingopyxis alaskensis DSM 13593(T) (98.09 %), Sphingopyxis witflariensis DSM 14551(T) (98.09 %), Sphingopyxis bauzanensis DSM 22271(T) (98.02 %), Sphingopyxis granuli KCTC 12209(T) (97.73 %), Sphingopyxis macrogoltabida KACC 10927(T) (97.49 %), Sphingopyxis ummariensis DSM 24316(T) (97.37 %) and Sphingopyxis panaciterrulae KCTC 22112(T) (97.09 %). The predominant fatty acids were C18 : 1ω7c, summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c), C14 : 0 2-OH and C16 : 0. The predominant menaquinone was MK-10. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and sphingoglycolipid. These chemotaxonomic data are common to members of the genus Sphingopyxis. However, a polyphasic approach using physiological tests, DNA base ratios, DNA-DNA hybridization and 16S rRNA gene sequence comparisons showed that the isolate SC13E-S71(T) belongs to a novel species within the genus Sphingopyxis, for which the name Sphingopyxis italica sp. nov. is proposed. The type strain is SC13E-S71(T) ( = DSM 25229(T) = CECT 8016(T)).