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 A4 alpha, L-Lys-L-Thr-D-Glu; whole-cell sugars (glucose, mannose and galactose); octa-, hexa- and tetrahydrogenated menaquinones with nine isoprene units; phosphatidylglycerol and diphosphaticlylglycerol as the major phospholipids; anteiso-C-15:0, iso-C-15:0 and iSO-C-16:0 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 15700(T) 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.