sp. nov., sp. nov. and sp. nov., marine, cellulolytic endosymbiotic bacteria isolated from the gills of the wood-boring mollusc (Bivalvia: Teredinidae) and emended description of the genus .

Here, we describe three endosymbiotic bacterial strains isolated from the gills of the shipworm, (Teredinidae: Bivalvia). These strains, designated as Bs08, Bs12 and Bsc2, are Gram-stain-negative, microaerobic, gammaproteobacteria that grow on cellulose and a variety of substrates derived from lignocellulose. Phenotypic characterization, phylogeny based on 16S rRNA gene and whole genome sequence data, amino acid identity and percentage of conserved proteins analyses, show that these strains are novel and may be assigned to the genus . The three strains may be differentiated and distinguished from other previously described species based on a combination of four characteristics: colony colour (Bs12, purple; others beige to brown), marine salt requirement (Bs12, Bsc2 and strains), the capacity for nitrogen fixation (Bs08 and strains) and the ability to respire nitrate (Bs08). Based on these findings, we propose the names sp. nov. (type strain Bs08=ATCC TSD-121=KCTC 62964), sp. nov. (type strain Bs12=ATCC TSD-122=KCTC 62965) and sp. nov. (type strain Bsc2=ATCC TSD-123=KCTC 62966).