Comparative Genome Analysis Provides Molecular Evidence for Reclassification of the Photosynthetic Bacterium Rhodobacter sphaeroides EBL0706 as a Strain of Luteovulum azotoformans

Abstract

In this study, we conducted a genome-wide comparative analysis of a former Rhodobacter sphaeroides strain EBL0706, which is now recorded as Luteovulum sphaeroides EBL0706. The genome of EBL0706 was compared with that of Luteovulum azotoformans ATCC 17025, Luteovulum azotoformans KA25, and Luteovulum sphaeroides 2.4.1. The average nucleotide identity (ANI), tetra nucleotide signatures (Tetra), digital DNA–DNA hybridization (dDDH) values, comparative genome, and phylogenetic analysis proposed that EBL0706 is a strain of Luteovulum azotoformans. Functional annotations identified a total of 4034 protein-coding genes in the genome of EBL0706, including a complete photosynthetic gene cluster. This study provides genomic molecular verification for the strain EBL0706 to be reclassified to Luteovulum azotoformans.

Falsirhodobacter algicola sp. nov., a member of the Rhodobacteraceae isolated from the marine red algae Grateloupia sp.

“…The ANI and dDDH values between strain PG104 T and other related taxa were clearly lower than the thresholds (<95 % ANI and <70 % dDDH) for prokaryotic species delineation (Table S2) [22, 23], suggesting that strain PG104 T represents new species of the family Rhodobacteraceae . Two genera, Rhodobacter and Cereibacter (synonym Catellibacterium , Gemmobcter , Luteovulum and Rhodobacter ), phylogenetically related to Falsirhodobacter have many of the photosynthesis-related genes such as photosystem II-type photosynthetic reaction centre and bacterial light-harvesting proteins [24, 25]. However, no photosynthesis-related genes were identified in the genomes of either Falsirhodobacter strain.…”