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The taxonomic position of an aerobic actinobacterial strain, BMG841(T), isolated from the Bulla Regia monument (Tunisia) and exhibiting a high resistance to gamma-radiation (D10 similar to 9 kGy) was determined using polyphasic approach. The optimal growth range was found to be 25-35 A degrees C at pH of 7.0-8.5. The strain was observed to form black dry colonies. Chemotaxonomic characteristics of the isolate showed a cell wall type III, with galactose and glucose as diagnostic sugars; phosphatidylcholine, phosphatidylinositol, diphosphatidylglycerol, phosphatidylethanolamine and an unidentified glycolipid as main polar lipids; and MK-9(H-4) as the predominant menaquinone. The major cellular fatty acids were identified as iso-C-16:0 and iso-C-15:0. Phylogenetic analysis indicated that strain BMG841(T) represents a novel member of the genus Geodermatophilus with high 16S rRNA gene sequence identity with Geodermatophilus saharensis (98.28 %). Based on phylogenetic and phenotypic analysis, strain BMG841(T) is proposed as the type strain (=DSM 46841(T) = CECT 8821(T)) of a novel species, Geodermatophilus bullaregiensis.