Friday 24 March 2023

Meet the latest extremophile: Sulfurimonas pluma

Image: Enceladus black smoker at the Aurora Vent Field (Source: HACON cruise 2021, REV Ocean)

How does microbial life survive deep in the ocean? Disconnected from the energy of the sun, the permanently ice-covered Arctic deep sea receives miniscule amounts of organic matter that could sustain life.


By Tim Sandle


Deep down in the ocean at tectonic plate boundaries, hot fluids rise from hydrothermal vents. These fluids are devoid of oxygen and contain large amounts of metals such as iron, manganese or copper. Some may also transport sulphides, methane and hydrogen. As the hot water mixes with the cold and oxygenated surrounding seawater, hydrothermal plumes develop containing smoke-like particles of metal sulphide. These plumes can rise hundreds of meters off the seafloor and disperse thousands of kilometres away from their source. 



The bacteria that exist in such extreme environments can harvest the energy released from submarine hydrothermal sources. Certain bacteria have adapted to the geo-energy floating in deep-sea waters by undertaking biogeochemical cycling.


Scientists from Max Planck Institute for Marine Microbiology have been examining bacteria of the genus Sulfurimonas. These bacteria have only grow in low-oxygen environments and their gene sequences have occasionally been detected in hydrothermal plumes.


These organisms use energy from sulphide and it appears that plumes might be a suitable environment for some members of the Sulfurimonas group.


Sulfurimonas is a bacterial genus within the class of Campylobacterota, known for reducing nitrate, oxidizing both sulphur and hydrogen. This genus consists of four species: Sulfurimonas autorophica, Sulfurimonas denitrificans, Sulfurimonas gotlandica, and Sulfurimonas paralvinellae. The genus' name is derived from "sulfur" (US spelling; ‘sulphur’ UK spelling).


Numerous environmental sequences and isolates of Campylobacterota have also been recovered from hydrothermal vents and cold seep habitats.


The size of the bacteria varies between about 1.5-2.5 μm in length and 0.5-1.0 μm in width. Members of the genus Sulfurimonas are found in a variety of different environments which include deep sea-vents, marine sediments, and terrestrial habitats. Their ability to survive in extreme conditions is attributed to multiple copies of an enzyme.


The researchers sampled plumes in extremely remote areas of ultraslow spreading ridges that had never been studied before. With the samples, the scientists studied the composition and metabolism of bacteria.


Here the scientists identified a new Sulfurimonas species called USulfurimonas pluma (the superscript "U" stands for uncultivated) inhabiting the cold, oxygen-saturated hydrothermal plumes.


This microorganism used hydrogen from the plume as an energy source, rather than sulphide. The scientists also investigated the microbes' genome and found it to be strongly reduced, missing genes typical for their relatives, but being well-equipped with others to allow them to grow in this dynamic environment.


These organisms have adapted to live in an ecological niche that is cold, oxygen-saturated and consists of hydrogen-rich hydrothermal plumes.


The research appears in the journal Nature Microbiology, titled “A hydrogenotrophic Sulfurimonas is globally abundant in deep-sea oxygen-saturated hydrothermal plumes.”


Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

No comments:

Post a Comment

Pharmaceutical Microbiology Resources

Special offers