Gordonia malaquae sp nov., isolated from sludge of a wastewater treatment plant

The taxonomic status of a bacterial isolate from the sludge of a wastewater treatment plant was characterized by using a polyphasic taxonomic approach. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV, short-chain mycolic acids that co-migrated with those extracted from members of the genus Gordonia, fatty acids C-16:0 and C-18:0 (found by pyrolysis gas chromatography) and a dihydrogenated menaquinone with nine isoprene units [MK-9(H2)] as the predominant menaquinone. The genus assignment was confirmed by 16S rRNA gene sequencing. Comparative analysis of the 16S rRNA gene sequence showed that the novel isolate constitutes a hitherto unknown subline within the genus Gordonia, displaying 95.9 to 97.6% gene sequence similarity to the recognized species of the genus. The novel isolate was distinguished from the type strains of phylogenetically related species by using a set of phenotypic features. The genotypic and phenotypic data show that the new strain merits classification as a novel species of the genus Gordonia, for which the name Gordonia malaquae sp. nov. is proposed. The type strain is IMMIB WWCC-22(T) (= DSM 45064(T)= CCUG 53555(T)).