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.

Tsuneonella suprasediminis sp. nov., isolated from the Pacific Ocean

A Gram-stain-negative, rod-shaped and aerobic bacterial strain, named Ery12^T, was isolated from the overlying water of the Lau Basin in the Southwest Pacific Ocean. Strain Ery12^T showed high 16S rRNA gene sequences similarity to Tsuneonella flava MS1-4^T (99.9 %), T. mangrovi MCCC 1K03311^T (98.1 %), Altererythrobacter ishigakiensis NBRC 107699^T (97.3 %) and exhibited ≤97.0 % sequence similarity with other type strains of species with validly published names. Growth was observed in media with 0-10.0 % NaCl (optimum 0-1.0 %, w/v), pH 5.0-9.5 (optimum 6.0-7.0) and 10-42 °C (optimum 30-37 °C). The predominant respiratory quinone was ubiquinone 10 (Q-10). The major cellular fatty acid was summed feature 8 (C_18 : 1  ω7c and/or C_18 : 1  ω6c). The major polar lipids were sphingoglycolipid, phosphatidyglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, three unidentified glycolipids, one unidentified aminoglycolipid and one unidentified lipid. The DNA G+C content was 60.8 %. The ANI and in silico DDH values between strain Ery12^T and the type strains of its closely related species were 71.0- 91.8 % and 19.5- 44.6 %, respectively. According to the phenotypic, chemotaxonomic, phylogenetic and genomic data, strain Ery12^T represents a novel species of the genus Tsuneonella, for which the name Tsuneonella suprasediminis is proposed. The type strain is Ery12^T (=CGMCC 1.16500 ^T=MCCC 1A04421^T=KCTC 62388^T). We further propose to reclassify Altererythrobacter rhizovicinus and Altererythrobacter spongiae as Pelagerythrobacter rhizovicinus comb. nov. and Altericroceibacterium spongiae comb. nov., respectively.