Pectobacterium aroidearum sp. nov., a soft rot pathogen with preference for monocotyledonous plants

Several pectolytic bacterial strains, mainly isolated from monocotyledonous plants and previously identified as Pectobacterium carotovorum, were thought to belong to a novel species after several taxonomic analyses including DNA–DNA hybridization. In 16S rRNA gene sequence analyses, these strains had a similarity of >97.9 % to the 16S rRNA gene sequence of strains representing six other pectobacterial species and subspecies. These strains, represented by strain SCRI 109^T, also showed some unique chemotaxonomic features and quantitative differences in polar lipids, lipoquinones and fatty acids. A specific feature of strain SCRI 109^T was the presence of DMK-8 lipoquinone, while the dominant fatty acids were the summed feature 3 (iso-C_15 : 0 2-OH/C_16 : 1ω7c), the unsaturated fatty acid C_18 : 1ω7c and straight chain fatty acids, mainly C_16 : 0. The DNA G+C content of strain SCRI 109^T was 50.2 mol%. The taxonomic status of strain SCRI 109^T and related strains in 16S rRNA gene sequence, chemotaxonomic, and physiological analyses was corroborated by the distinct clustering of these strains in multi-locus sequence analyses. It is proposed that these strains represent a novel species for which the name Pectobacterium aroidearum sp. nov. is proposed; the type strain is SCRI 109^T ( = NCPPB 929^T = LMG 2417^T = ICMP 1522^T).