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

Abstract

A Gram-type-positive, strictly aerobic actinobacterium, designated strain MON 2.2T, 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 (~95 % similarity) found in the public databases were uncultured actinobacteria, while the closest cultured members indicated a phylogenetic relationship with members of the familyPropionibacteriaceae(92–95 % similarity). Subsequent phylogenetic analysis placed the new isolate within the radiation of the generaFriedmanniellaandMicrolunatus, but forming an independent branch. Chemotaxonomic markers were consistent with the classification of strain MON 2.2Tin the familyPropionibacteriaceae, amongst the genera containingll-diaminopimelic acid in their peptidoglycan. Characteristic fatty acids iso-C15 : 0and anteiso-C15 : 0also supported its affiliation to this taxon; however, polar lipid and menaquinone compositions clearly differentiated strain MON 2.2Tfrom 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 2.2Tbe classified in a novel species in a new genus, for which the nameAuraticoccus monumentigen. nov., sp. nov. is proposed. The type strain ofAuraticoccus monumentiis MON 2.2T( = CECT 7672T = DSM 23257T = LMG 25551T).