Description of Dryocola gen. nov. and two novel species, Dryocola boscaweniae sp. nov. and Dryocola clanedunensis sp. nov. isolated from the rhizosphere of native British oaks

Abstract

While investigating the role of the rhizosphere in the development of Acute Oak Decline, bacterial strains belonging to the family Enterobacteriaceae were isolated from rhizosphere soil following enrichment for the Enterobacterales. Partial sequencing of several housekeeping genes showed that these strains could not be assigned to an existing genus. Overall, 16 strains were investigated using a polyphasic approach to determine their taxonomic status. This involved phenotypic testing and fatty acid analysis paired with phylogenetic analyses of 16S rRNA and housekeeping gene sequences, as well as phylogenomic analysis of whole genome sequences. Phylogenomic and phylogenetic analyses consistently demonstrated that the 16 isolates could be separated into two distinct clusters in a monophyletic clade situated between the genera Cedecea and Buttiauxella. The two clusters could be genotypically and phenotypically differentiated from each other and from their closest neighbours. As such we propose the description of Dryocola boscaweniae gen. nov. sp. nov. (type strain H6W4^T = CCUG 76177^T = LMG 32610^T) and Dryocola clanedunesis sp. nov. (type strain H11S18^T = CCUG 76181^T = LMG 32611^T).

Keywords: AOD; Enterobacteriaceae; Oak; Rhizosphere; Soil.