Microbacterium tenebrionis sp. nov. and Microbacterium allomyrinae sp. nov., isolated from larvae of Tenebrio molitor L. and Allomyrina dichotoma, respectively

Abstract

Two Gram-positive bacterial strains, designated as YMB-B2T and BWT-G7T, were isolated from larvae of Tenebrio molitor L. and Allomyrina dichotoma, respectively, and their taxonomic positions examined by a polyphasic approach. Both of the isolates contained ornithine as the cell-wall diamino acid. The acyl type of murein was N-glycolyl. The predominant menaquinones were MK-11 and MK-12. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid. Both of the isolates contained C15 : 0 anteiso and C17 : 0 anteiso as the major fatty acids. Strain YMB-B2T also had C16 : 0 iso as an additional major fatty acid. The 16S rRNA gene phylogeny showed that the novel strains formed two distinct sublines within the genus Microbacterium . Strain YMB-B2T was most closely related to the type strains of Microbacterium aerolatum (99.1 % sequence similarity) and Microbacterium ginsengiterrae (99.0 %), whereas strain BWT-G7T formed a tight cluster with the type strain of Microbacterium thalassium (98.9 %). The phylogenomic analysis based on 92 core genes supported their relationships in 16S rRNA gene phylogeny. Overall genomic relatedness indices warranted that the isolates represent two new species of the genus Microbacterium . Based on the results obtained here, Microbacterium tenebrionis sp. nov. (type strain YMB-B2T=KCTC 49593T=CCM 9151T) and Microbacterium allomyrinae sp. nov. (type strain BWT-G7T=KACC 22262T=NBRC 115127T) are proposed.