Actinotalea caeni sp. nov., isolated from a sludge sample of a biofilm reactor.

A polyphasic taxonomic study was carried out on strain EBR-4-2T isolated from a biofilm reactor in Korea. Cells of the strain were Gram-stain-positive, non-spore-forming, non-motile and rod-shaped. Comparative 16S rRNA gene sequence studies showed the clear affiliation of this strain to the Actinobacteria, and it had the highest pairwise sequence similarities with Actinotalea suaedae EGI 60002T (98.7 %), Actinotalea ferrariae CF5-4T (96.3 %) and Actinotalea fermentans DSM 3133T (96.2 %). Phylogenetic analysis based on the 16S rRNA gene sequences showed that the strain formed a clear phylogenetic lineage with the genus Actinotalea. The major fatty acids were identified as C15 : 0 anteiso, C16 : 0, C16 : 0 N alcohol, C15 : 1 anteiso A and C15 : 0 iso. The major cellular polar lipids were diphosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol and glycolipid. The peptidoglycan type was A4β containing l-Orn-d-Glu. The whole-cell-wall sugars were glucose and ribose. The respiratory quinone was identified as menaquinone MK-10(H4), and the genomic DNA G+C content was determined to be 74.8 mol %. Based on evidence from this polyphasic study, it is proposed that strain EBR-4-2T should be designated as representing a novel species named Actinotalea caeni sp. nov. The type stain is EBR-4-2T (=KCTC 33604T=JCM 30447T).