Maribellus comscasis sp. nov., isolated from the deep-sea cold seep

A facultatively anaerobic, Gram-stain-negative, non-motile, curved rod-shaped bacterium, designated WC007T, was isolated from the deep-sea cold seep, P. R. China. Strain WC007T was found to grow at temperatures from 28 to 37 °C (optimum, 30 °C), at pH values between pH 6.0 and 8.0 (optimum, pH 7.0) and in 0-5.0% (w/v) NaCl (optimum, 1.0%). The major fatty acids (>10.0%) were iso-C15:0, C16:0, summed feature 3 and summed feature 8.

The major isoprenoid quinone was MK-7. Predominant polar lipids were phosphatidylethanolamine, one unidentified phospholipid, one unidentified aminolipid and one unidentified lipid. The G+C content of the genomic DNA was 38.38%. The average nucleotide identity (ANIb and ANIm), amino acid identity (AAI), the tetranucleotide signatures (Tetra) and in silico DNA-DNA hybridization (isDDH) similarities between the genome sequences of isolate WC007T and Maribellus luteus XSD2T were 70.11%, 84.94%, 71.0%, 0.92022 and 20.40%, respectively, indicating that strain WC007T was distinguished from M. luteus.

Phylogenetic analysis based on 16S rRNA gene sequences placed strain WC007T within the genus Maribellus and showed the highest similarity to strain XSD2T (95.70%). In combination of the results of phylogenetic analysis and phenotypic and chemotaxonomic data, strain WC007T was considered to represent a novel species of the genus Maribellus, for which the name Maribellus comscasis sp. nov. is proposed. The type strain is WC007T (=KCTC 25169T = MCCC 1K04777T).

The available of the genome sequence of strain WC007T would be helpful in understanding the degradation mechanism of difficult-to-degrade polysaccharides.

Authors: Rikuan Zheng, Chaomin Sun