Lactobacillus nasuensis sp. nov., a lactic acid bacterium isolated from silage, and emended description of the genus Lactobacillus

Abstract

Two strains of lactic acid bacteria, designated SU 18T and SU 83, were isolated from silage prepared with Sudan grass [Sorghum sudanense (Piper) Stapf.]. The isolates were Gram-stain-positive, catalase-negative, facultatively anaerobic rods that did not produce gas from glucose. The isolates exhibited ≥93.5 % DNA–DNA relatedness to each other and shared the same phenotypic characteristics, which indicated that they belonged to a single species. The DNA G+C content was 58.5–59.2 mol%. On the basis of 16S rRNA gene sequence analysis, the isolates were placed in the genus Lactobacillus . Their closest phylogenetic neighbours were Lactobacillus manihotivorans JCM 12514T and Lactobacillus camelliae JCM 13995T (95.9 and 96.8 % 16S rRNA gene sequence similarity, respectively, with strain SU 18T). Ribotyping revealed that strain SU 18T was well separated from L. manihotivorans JCM 12514T and L. camelliae JCM 13995T. Strain SU 18T exhibited ≤23.7 % DNA–DNA relatedness with its closest phylogenetic neighbours. The isolates represent a novel species in the genus Lactobacillus , for which the name Lactobacillus nasuensis sp. nov. is proposed. The type strain is SU 18T ( = JCM 17158T  = CGMCC 1.10801T). The description of the genus Lactobacillus is also amended.