Myceligenerans crystallogenes sp. nov., isolated from Roman catacombs

Three xylan-degrading actinobacterial strains were isolated from different sampling sites in the Roman catacombs of Domitilla and San Callisto. The organisms showed morphological and chemotaxonomic properties such as peptidoglycan type A4α, l-lys–l-thr–d-Glu; whole-cell sugars (glucose, mannose and galactose); octa-, hexa- and tetrahydrogenated menaquinones with nine isoprene units; phosphatidylglycerol and diphosphatidylglycerol as the major phospholipids; anteiso-C15 : 0, iso-C15 : 0 and iso-C16 : 0 as the predominant fatty acids; and a DNA G+C content of 72 mol%. These features are consistent with affiliation of these isolates to the genus Myceligenerans. The three isolates shared a 16S rRNA gene similarity of 99·9 % and were most closely related to Myceligenerans xiligouense DSM 15700^T (97·9 % sequence similarity). The low level of DNA–DNA relatedness (about 14 %) and the differences in phenotypic characteristics between the novel strains and M. xiligouense DSM 15700T justify the proposal of a novel species of the genus Myceligenerans, Myceligenerans crystallogenes sp. nov., with CD12E2-27^T (=HKI 0369^T=DSM 17134^T=NCIMB 14061^T=VTT E-032285^T) as the type strain.