RESUMO
Gram-negative-staining bacteria that were resistant to monoterpene myrcene (7-methyl-3-methylene-1.6-octadiene, C10H16, at concentrations of up to 10 µl ml(-1) in TSB) were isolated from the gut contents of adult bark beetles Ips typographus (Coleoptera, Scolytidae). The beetles were collected from the bark of Norway spruce (Picea abies) in Lithuania. Bark beetles feed on conifers, which produce myrcene among many other defensive compounds. It has been suggested that the micro-organisms present within the beetles' guts could be involved in their resistance towards this plant defensive compound. The most resistant bacterial strains were isolated and characterized by phenotypic assays as well as fatty acid analysis, 16S rRNA gene sequencing, multilocus sequence analyses (MLSA) based on the rpoB, atpD and infB genes and DNA-DNA hybridization. Biochemical characterization indicated that the bacteria belonged to the family Enterobacteriaceae. Phylogenetic analyses of the 16S rRNA gene sequences and MLSA of the novel strains revealed that they belonged to the genus Erwinia, but represented a novel species. The dominant cellular fatty acids were C16:0 and C17:0 cyclo. The DNA G+C content was 49.1 mol%. The results obtained in this study indicated that these bacteria from the bark beetle gut represented a novel species, for which the name Erwinia typographi sp. nov. is proposed, with the type strain DSM 22678T (=Y1T=LMG 25347T).