Christiangramia pacifica sp. nov. and Christiangramia profundi sp. nov., two novel species isolated from deep-sea environments of the Pacific Ocean.

Abstract

Two Gram-negative, aerobic, motile and rod-shaped bacterial strains, designated D34-3ᵀ and BC02-3-A7ᵀ, were isolated from deep-sea sediments of the eastern Pacific Ocean. Both strains were able to grow in the presence of 1.0-10.0% (wt/v) NaCl, at pH 6-9 and at 10-37 °C. The 16S rRNA gene sequence comparisons confirmed that these two isolates belonged to the genus Christiangramia of the family Flavobacteriaceae, exhibiting the highest 16S rRNA gene sequence similarity of D34-3ᵀ to Christiangramia sediminicola SM2212^T (98.8%) and BC02-3-A7ᵀ to Christiangramia oceanisediminis GC03-9ᵀ (97.2%), respectively. The complete genomes of D34-3ᵀ and BC02-3-A7ᵀ were 3.40 Mb (G+C content 37.5 mol%) and 4.43 Mb (G+C content 40.6 mol%) in size, with average nucleotide identity and digital DNA-DNA hybridization values with other reference Christiangramia species below 79.3/21.7% and 76.5/19.7%, respectively. Strain D34-3ᵀ contained menaquinone-6 as the sole respiratory quinone while menaquinone-7 was detected as the only respiratory quinone for BC02-3-A7ᵀ. These two strains possessed phosphatidylethanolamine as the dominant polar lipid. The predominant cellular fatty acids of both these strains were iso-C15 : 0, iso-C17 : 0 3-OH, summed feature 3 (C_16 : 1  ω7c and/or C_16 : 1  ω6c) and summed feature 9 (iso-C_17 : 1  ω9c and/or 10-methyl C_16 : 0). Based on phenotypic, chemotaxonomic and genomic characteristics, strains D34-3ᵀ and BC02-3-A7ᵀ were identified as two novel species of the genus Christiangramia, for which the names Christiangramia pacifica sp. nov. and Christiangramia profundi sp. nov. are proposed; the type strains are D34-3ᵀ (=MCCC 1A13342^T=DSM 121736^T) and BC02-3-A7ᵀ (=MCCC M23243^T =DSM 121737^T), respectively.