Abstract

A bacterial strain PBT33-2T was isolated from the air environ-ment in an indoor pig farm. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain PBT33-2T be-longed to the genus Nocardioides in the phylum Actinobac-teria, and was most closely related to Nocardioides daphnia D287T in a maximum-likelihood and neighbor-joining phy-logenetic trees. Strain PBT33-2T shared 95.3% sequence iden-tity with N. daphnia D287T. However, the highest sequence similarity was shown with N. sediminis MSL-01T (96.0%). It had less than 96.0% sequence identities with other type spe-cies of the genus Nocardioides. Strain PBT-33-2T grew at 15–45°C (optimum 20–35°C), pH 5.0–11.0 (optimum pH 7.0) and 0–4.0% (w/v) NaCl (optimum 0%). The major fatty acid and quinone were iso-C16:0 and MK-8, and the DNA G+C content of strain PBT33-2T was 69.3 mol%. On the basis of poly-phasic results, strain PBT33-2T represents a novel spe-cies of the genus Nocardioides, for which the name Nocar-dioides suum sp. nov. is proposed. Its type strain is PBT33-2T (=KCTC 39558T =DSM 102833T).

• Keywords: Actinobacteria; air environment; nocardioides; pig farm