Mixta tenebrionis sp. Nov., isolated from the gut of the plastic-eating mealworm Tenebrio molitor L.

A bacterial strain, BIT-26^T, was isolated from the gut of plastic-eating mealworm Tenebrio molitor L. The taxonomic position of this new isolate was investigated by using a polyphasic approach. Cells of the strain were Gram-stain-negative, facultatively anaerobic, motile rods with peritrichous flagella. The 16S rRNA gene sequence (1412 bp) of strain BIT-26^T showed the highest similarity (97.4%) to Erwinia piriflorinigrans CFBP 5888^T, followed by Citrobacter sedlakii NBRC 105722^T (97.3%), Mixta calida LMG 25383^T (97.3%), Cronobacter muytjensii ATCC 51329^T (97.2%) and Mixta theicola QC88-366^T (97.2%). The results of phylogenetic analyses, based on the 16S rRNA gene and concatenated sequences of four housekeeping genes (atpD, gyrB, infB and rpoB), placed strain BIT-26^T within the genus Mixta of the family Erwiniaceae. This affiliation was also supported by the chemotaxonomic data. Strain BIT-26^T had similar predominant fatty acids, including C_{12: 0}, C_{14: 0}, C_{16: 0}, C_{17: 0} cyclo and C_{19: 0} cyclo ω8c, to species of the genus Mixta. In silico DNA–DNA hybridization and average nucleotide identity calculations plus physiological and biochemical tests allowed the genotypic and phenotypic differentiation of strain BIT-26^T from other species of the genus Mixta with validly published names. Therefore, strain BIT-26^T is considered to represent a novel species, for which the name Mixta tenebrionis sp. nov is proposed. The type strain is BIT-26^T (=CGMCC 1.17041^T=KCTC 72449^T).