Thermococcus atlanticus

Classification

Higher order taxa

Domain: Bacteria Phylum: Deinococcota Class: Deinococci Family: Thermaceae Genus: Thermus

Species

Species:T.aquaticus Binomial name: Thermus aquaticus strain MA898

Description and significance

Thermococcus atlanticus was isolated from deep-sea hydrothermal vents on the Mid-Atlantic Ridge. This Archaeon is extremely thermophilic with a preferred temperature of 85 degrees C. This strain also has an optimal NACL concentration of 3% and pH of 7 for growth. This microorganism requires rich proteinaceous substrates and prefers environments with Polysulfur, L-cysteine, cystine, or elemental sulfur. The strain is an aerobic coccus and grows up to 1.2μm in diameter. Thermococcus atlanticus is an obligate heterotroph that prefers to grow on proteinaceous substrates. The genera of Thermococcus are being studied for biotechnological purposes regarding DNA polymerases or conjugative plasmids. Thermococcus atlanticus is understudied but could lead to future innovations.

Fig. 1 Scanning electron micrograph of strain MA898. Scale represents 2 μm

16S Ribosomal RNA Gene Information

The Mol% G+C content of the DNA Isolate MA898 was 50% according to thermal denaturation. 16S rRNa gene sequencing of the strain determined that it is affiliated with Thermococcus species. The similarity of this strain with other Thermococcus species was found to be up to 98%.

Phylogenetic relationships based on 16S rRNA sequences. The topology shown is a consensus tree obtained with the three methods (neighbor joining, maximum parsimony and maximum likelihood)

Cell structure and metabolism

Strain MA898 known as Thermococcus atlanticus is single-celled and ranges in size from .7 to 1.2 μm. The bacterial cells were observed as being nonmotile. The cells likely divide through constriction. The cells have a slightly irregular cocci shape and live as a form of plankton. This microbe is an obligate anaerobic chemoorganotroph. T.atlanticus exhibited an ARDRA pattern different from all previously known Thermococcus strains. Growth of the cells occurs in a pH range of 5-8. Growth was also found to occur in the presence of NaCl between 15.3 g/l to 46 g/l. In the presence of elemental sulfur T.atlanticus produces Hydrogen sulfide.

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Ecology and Pathogenesis

T.atlanticus is found in the mid-Atlantic Ocean at deep-sea hydrothermal vents. They thrive in high-temperature and high-pressure environments. It also preferentially grows in the presence of elemental sulfur, polysulfur, cystine, or L-cysteine. This strain also requires a protein rich substrate. This species was found in the chimney wall of hydrothermal vents, it is a new hyperthermophilic, heterotrophic archaeal species.

References

Cambon-bonavita, M., Lesongeur, F., Pignet, P., Wery, N., Lambert, C., Godfroy, A., Querellou, J., & Barbier, G. (2003). Extremophiles, Thermophily section, species description Thermococcus atlanticus sp. nov., a hyperthermophilic Archaeon isolated from a deep-sea hydrothermal vent in the Mid-Atlantic Ridge. Extremophiles, 7(2), 101-9. https://doi.org/10.1007/s00792-002-0301-8

Author

Maura Cleary, a student of Dr. Hidetoshi Urakawa of Florida Gulf Coast University for Microbial Ecology EVR 4024C spring 2023.