Cells from strain GE09T, isolated from an artificially immersed nanofibrous cellulose plate in the deep sea, were Gram-stain-negative, motile, aerobic cells that could grow with cellulose as their only nutrient. Strain GE09T was placed among members of Cellvibrionaceae, in the Gammaproteobacteria, with Marinagarivorans algicola Z1T, a marine degrader of agar, as the closest relative (97.4 % similarity). The average nucleotide identity and digital DNA-DNA hybridization values between GE09T and M. algicola Z1T were 72.5 and 21.2 %, respectively. Strain GE09T degraded cellulose, xylan and pectin, but not starch, chitin and agar. The different carbohydrate-active enzymes encoded in the genomes of strain GE09T and M. algicola Z1T highlights their differences in terms of target energy sources and reflects their isolation environments. The major cellular fatty acids of strain GE09T were C18 : 1 ω7c, C16 : 0 and C16 : 1 ω7c. The polar lipid profile showed phosphatidylglycerol and phosphatidylethanolamine. The major respiratory quinone was Q-8. Based on these distinct taxonomic characteristics, strain GE09T represents a new species in the genus Marinagarivorans, for which we propose the name Marinagarivorans cellulosilyticus sp. nov. (type strain GE09T=DSM 113420T=JCM 35003T).
Keywords: Cellvibrionaceae; cellulose degradation; deep sea.