Nocardioides suum sp. nov. isolated from the air environment in an indoor pig farm.

A bacterial strain PBT33-2T was isolated from the air environment in an indoor pig farm. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain PBT33-2T belonged to the genus Nocardioides in the phylum Actinobacteria, and was most closely related to Nocardioides daphnia D287T in a maximum-likelihood and neighbor-joining phylogenetic trees. Strain PBT33-2T shared 95.3% sequence identity 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 species 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 species of the genus Nocardioides, for which the name Nocardioides suum sp. nov. is proposed. Its type strain is PBT33-2T (=KCTC 39558T =DSM 102833T).