Genome-based reclassification of Terribacillus goriensis (Kim et al. 2007) Krishnamurthi and Chakrabarti 2009 as a later heterotypic synonym of Terribacillus saccharophilus An et al. 2007

Abstract

The present study used whole-genome data to clarify the taxonomic assignment of two closely related Terribacillus species. The genus Terribacillus includes four species with validly published names, Terribacillus aidingensis, T. goriensis, T. halophilus and T. saccharophilus. The type species T. saccharophilus 002-048^T (=IAM 15309^T=KCTC 13936^T) was isolated from the soil in Japan, while T. goriensis CL-GR16^T (=KCCM 42329^T=DSM 18252^T) was isolated from the coastal water off the east coast of Korea. Both strains have similar phenotypic and chemotaxonomic characteristics. Anteiso-C_{15 : 0} was the major fatty acid, followed by anteiso-C_{17 : 0} and iso-C_{15 : 0}. There were similar major menaquinones (MK-7). As determined by whole-genome sequencing, the DNA G+C content of 42.53 and 42.66 mol% was found for T. saccharophilus and T. goriensis, respectively, and they were 99.86% identical in their 16S rRNA gene sequences (1,421 bp). Genomic comparisons showed the average nucleotide identity was 98.29% and 84.80% for digital DNA-DNA hybridization. These values exceeded the threshold values for bacterial species delineation. Using the Type (Strain) Genome Server, both species were identified as T. saccharophilus. Phylogenetic analysis based on both 16S rRNA gene sequences and whole-genome sequences showed that they form a separate cluster apart from members of other genera. Based on the combined evidence, Terribacillus goriensis Kim et al. (Int J Syst Evol Microbiol 2007;57:1554-1560), Krishnamurthi and Chakrabarti (Int J Syst Evol Microbiol 2008;58:2287-2291) is proposed to be a later heterotypic synonym of An et al. (Int J Syst Evol Microbiol 2007;57:51-55).

Keywords: Terribacillus goriensis; Terribacillus saccharophilus; heterotypic synonym.