Pseudorhodobacter turbinis sp. nov., isolated from the gut of the Korean turban shell, Turbo cornutus

An Update on Novel Taxa and Revised Taxonomic Status of Bacteria (Including Members of the Phylum Planctomycetota) Isolated from Aquatic Host Species Described in 2018 to 2021

Increased interest in farmed aquatic species, aquatic conservation measures, and microbial metabolic end-product utilization have translated into a need for awareness and recognition of novel microbial species and revisions to bacterial taxonomy. Because this need has largely been unmet, through a 4-year literature review, we present lists of novel and revised bacterial species (including members of the phylum Planctomycetota) derived from aquatic hosts that can serve as a baseline for future biennial summaries of taxonomic revisions in this field. Most new and revised taxa were noted within oxidase-positive and/or nonglucose fermentative Gram-negative bacilli, including members of the Tenacibaculum, Flavobacterium, and Vibrio genera. Valid and effectively published novel members of the Streptococcus, Erysipelothrix, and Photobacterium genera are additionally described from disease pathogenesis perspectives.

Nocardioides palaemonis sp. nov. and Tessaracoccus palaemonis sp. nov., isolated from the gastrointestinal tract of lake prawn

Two novel Gram-stain-positive, non-motile and non-spore-forming bacterial strains, designated J2M5^T and J1M15^T, were isolated from the gastrointestinal tract of a lake prawn Palaemon paucidens. Strain J2M5^T was an obligately aerobic bacterium that formed milky-coloured colonies and showed a rod-coccus cell cycle, while strain J1M15^T was a facultatively aerobic bacterium that formed orangish-yellow-coloured colonies and showed rod-shaped cells. Strains J2M5^T and J1M15^T showed the highest 16S rRNA gene sequence similarity to Nocardioides ganghwensis JC2055^T (98.63 %) and Tessaracoccus flavescens SST-39^T (98.08 %), respectively. The whole-genome sequence of strain J2M5^T was 4.52 Mbp in size and the genomic G+C content directly calculated from the genome sequence of strain J2M5^T was 72.5 mol%. The whole-genome sequence of strain J1M15^T was 3.20 Mbp in size and the genomic G+C content directly calculated from the genome sequence of strain J1M15^T was 69.6mol %. Strains J2M5^T and J1M15^T showed high OrthoANI similarity to N. ganghwensis JC2055^T (83.6 %) and T. flavescens (77.2 %), respectively. We analysed the genome sequences of strains J2M5^T and J1M15^T in terms of carbohydrate-active enzymes, antibiotic resistance genes and virulence factor genes. Strains J2M5^T and J1M15^T contained MK-8 (H₄) and MK-9 (H₄) as the predominant respiratory quinones, respectively. The major polar lipids of both strains were phosphatidylglycerol and diphosphatidylglycerol. Additionally, strain J2M5^T possessed phosphatidylcholine, phosphatidylserine and phosphatidylethanolamine. The cellular sugar components of strain J2M5^T were ribose, mannose, glucose and galactose, and its cellular amino acid components were l-alanine and l-lysine. The cellular sugar components of strain J1M15^T were rhamnose, ribose, mannose and glucose, and its cellular amino acid component was l-alanine. The major cellular fatty acids of strains J2M5^T and J1M15^T were iso-C_{16 : 0} and anteiso-C_15 : 0, respectively. The multiple taxonomic analyses indicated that strains J2M5^T and J1M15^T represent novel species of the genus Nocardioides and Tessaracoccus, respectively. We propose the names Nocardioides palaemonis sp. nov. and Tessaracoccus palaemonis sp. nov. for strain J2M5^T (=KCTC 49461^T=CCUG 74767^T) and strain J1M15^T (=KCTC 49462^T=CCUG 74766^T), respectively.