Auraticoccus monumenti gen. nov., sp nov., an actinomycete isolated from a deteriorated sandstone monument

A Gram-type-positive, strictly aerobic actinobacterium, designated strain MON 2.2(T), was isolated from the surface of a sandstone monument. Cells with a coccoid shape, arranged in pairs or clusters, were non-motile and did not produce spores. The 10 closest 16S rRNA gene sequence matches (similar to 95% similarity) found in the public databases were uncultured actinobacteria, while the closest cultured members indicated a phylogenetic relationship with members of the family Propionibacteriaceae (92-95% similarity). Subsequent phylogenetic analysis placed the new isolate within the radiation of the genera Friedmanniella and Microlunatus, but forming an independent branch. Chemotaxonomic markers were consistent with the classification of strain MON 2.2(T) in the family Propionibacteriaceae, amongst the genera containing LL-diaminopimelic acid in their peptidoglycan. Characteristic fatty acids iso-C-15:0 and anteiso-C-15:0 also supported its affiliation to this taxon; however, polar lipid and menaquinone compositions clearly differentiated strain MON 2.2(T) from other genera in the family. On the basis of these results and additional physiological data obtained in the present study, it is proposed that strain MON 2.2(T) be classified in a novel species in a new genus, for which the name Auraticoccus monumenti gen. nov., sp. nov. is proposed. The type strain of Auraticoccus monumenti is MON 2.2(T) (=CECT 7672(T) = DSM 23257(T) = LMG 25551(T)).