Paenibacillus humicus sp. nov., isolated from poultry litter compost

Abstract

Two bacterial strains, PC-142 and PC-147T, isolated from poultry litter compost, were characterized with respect to their phenetic and phylogenetic characteristics. The isolates were endospore-forming rods that were reddish in colour after Gram staining. They were catalase- and oxidase-positive, were able to degrade starch and gelatin and grew at 15–40 °C and pH 5.5–10.0. The predominant fatty acids were anteiso-C15 : 0, iso-C15 : 0 and iso-C16 : 0, the major respiratory quinone was menaquinone MK-7, the cell-wall peptidoglycan was of the A1γ type and the G+C content of the DNA was 58 mol%. The 16S rRNA gene sequence analysis and phenetic characterization indicated that these organisms belong to the genus Paenibacillus, with Paenibacillus pasadenensis SAFN-007T as the closest phylogenetic neighbour (97.5 %). Strains PC-142, PC-147T and P. pasadenensis SAFN-007T represent a novel lineage within the genus Paenibacillus, characterized by a high DNA G+C content (58–63 mol%). The low levels of 16S rRNA gene sequence similarity with respect to other taxa with validly published names and the identification of distinctive phenetic features in the two isolates indicate that strains PC-142 and PC-147T represent a novel species of the genus Paenibacillus, for which the name Paenibacillus humicus sp. nov. is proposed. The type strain is PC-147T (=DSM 18784T =NBRC 102415T =LMG 23886T).