Pectobacterium colocasium sp. nov. isolated from taro (Colocasia esculenta)

ABSTRACT Pectobacterium , agenus comprising gram-negative, pectinolytic phytopathogens, is responsible for economic losses in a wide host range of plants. In this study, the bacterial strains PL152 T and PL155 were isolated from taro corms in Hawai’i in 2018, and characterized using genomic and biochemical assays. The Next Generation Sequencing technologies, Oxford Nanopore MinION and Illumina NovaSeq, were used for whole genome sequencing of the PL152 T strain. Short and long reads were assembled using the Unicycler tool accessible at the bioinformatic resource center, and PATRIC (PathoSystems Resource Integration Center) was used to generate a more accurate and reliable “hybrid” assembly. The 16S rRNA analysis of PL152 T with type strains of other known Pectobacterium species showed a close relationship with P. fontis . Multi-locus sequence analysis using nine housekeeping genes ( dnaA, gapA, gyrB, recA, dnaN, rpoS, mdh, rpoA and dnaK) differentiated strain PL152 T from other species of Pectobacterium and formed a unique and well-defined clade. The concurrent results of average nucleotide identity (ANI) and digital DNA-DNA hybridization, with calculated values lower than 95 and 70%, respectively, supported the delineation of a novel bacterial species. Here, we proposed Pectobacterium colocasium , strain PL152 T (=ICMP 24362 T ; LMG 32536 T ) and PL155 as a novel species in the genus Pectobacterium . 1.5 Repositories CP091064; MZ542535 - MZ542540; OM457660