A Novel n-Hexadecane-Degrading Bacterium Provisionally Named “Thermalkanevorax longiformis” Isolated from a Deep-Sea Hydrothermal Vent
TL;DR
These findings provide a cultivated representative of the family Symbiobacteriaceae with physiological and metabolic responses to n-hexadecane, thereby providing a basis for further investigation of hydrocarbon metabolism.
Abstract
Hydrothermal systems contain diverse alkanes derived from biological and geological processes, providing potential carbon and energy sources for microorganisms. However, cultivated thermophilic alkane-utilizing bacteria from hydrothermal environments remain poorly characterized. In this study, a strain L01 was isolated from a deep-sea hydrothermal vent and identified as an alkane-degrading bacterium. The strain L01 grew at 55 °C and pH 7.0 in medium supplemented with n-hexadecane under microoxic conditions. Cells were elongated rods approximately 10–20 μm long and ~0.2 μm wide. Phylogenetic analyses based on 16S rRNA gene sequence similarity (93.11% to the closest described relative), average amino acid identity (AAI, 66.27–66.58%), average nucleotide identity (ANI, 80.80–83.05%), and digital DNA-DNA hybridization (dDDH, 12.5–20.8%) demonstrated that strain L01 represents a previously unrecognized genus within the family Symbiobacteriaceae, for which the provisional name “Thermalkanevorax longiformis” is proposed. An isotope tracing experiment together with genomics and transcriptomics revealed coordinated physiological and metabolic responses associated with n-hexadecane utilization by strain L01. These findings provide a cultivated representative of the family Symbiobacteriaceae with physiological and metabolic responses to n-hexadecane, thereby providing a basis for further investigation of hydrocarbon metabolism.