Unique new species of marine bacteria discovered in deep-sea cold comb

Researchers have discovered a new type of marine bacteria that reproduces through a unique budding process and releases viruses to facilitate nitrogen metabolism.

Researchers have isolated a new strain of marine bacteria with unique characteristics from the ocean floor.

The study, recently published in the journal eLifeIt was hailed by the authors as a significant contribution to our understanding of physiological processes in the deep sea. Planctomycetes Bacteria. It highlights unique attributes, including its single cell division pattern, that set it apart as known. species in the class of Physics Bacteria that use a unique growing pattern of division.

It also provides what the authors say is definitive evidence that the new species is highly involved in nitrogen assimilation and living in chronic conditions. Virus (Bacteriophage) It facilitates nitrogen metabolism. Nitrogen cycling by bacteria is an essential process that releases nitrogen to form nucleic acids. Amino acidsAnd proteins—the building blocks of life.

„Until recently, most research Planctomycetes Due to the logistical difficulties associated with sampling and culturing deep-sea strains, the bacterial family has focused on strains from freshwater and shallow marine environments,” says lead author Riguan Zheng, a research associate at the Institute of Oceanology, Chinese Academy of Sciences. Beijing, China, and National Laboratory for Marine Science and Technology, Qingdao, China. „Most of them Planctomycetes Bacteria have been isolated using nutrient-poor growth media, so we wanted to see if using nutrient-rich media would make culture possible and further characterize members of this poorly understood family.

A novel bacterium, Poriferisphaera heterotrophis, observed using transmission electron microscopy (TEM). Abbreviations: CM, outer membrane; pi, cytoplasm; R, ribosome; N, nucleoid; ICM, cytoplasmic membrane; Bye, peribla. Credit: Riquan Zheng

To isolate the novel bacterium, the team took sediment samples from deep-sea coolers. Planctomycetes The bacteria are known to survive, and then a stable growth medium is supplemented with the antibiotic rifampicin and sources of nitrogen to promote their growth. They cultured these enriched bacteria on agar and further evaluated individual colonies by genome sequencing.

Among the bacteria, they found a strain called ZRK32 that grew faster than the others and may be a member of the genus. Poriferisphaera. To confirm this, the team compared the genetic similarities between this strain and other members Poriferisphaera genus and it was found to be distinguishable Poriferisphaera corsica, The only species with a valid published name. This suggests that ZRK32 is a new species – as the team proposes to call it Poriferisphaera heterotrophis.

To learn more about this new species, the team studied its growth and how it reproduces. They figured it out unlike anyone else Planctomycetes family members, Poriferisphaera heterotrophis Grows best in nutrient-rich media and multiplies by the budding mechanism, where parent cells form growth buds that develop into daughter cells.

as Planctomycetes The bacterial family is known to play an important role in nitrogen cycling, and the team next investigated whether this was also the case. Poriferisphaera heterotrophis. To test this, they looked at the effects of various nitrogen-containing substances such as nitrates, ammonia and nitrogen dioxide. Poriferisphaera heterotrophis Development. They found that adding nitrogen in the form of nitrate or ammonia increased growth, whereas adding it as nitrite inhibited growth.

They also discovered that adding nitrate or ammonia caused the novel strain to release a bacteriophage – a type of virus that infects bacteria. Bacteriophages are widely distributed in the oceans and can regulate nitrogen metabolism in their host bacteria. This bacteriophage – called phage-ZRK32 – was able to increase its growth Poriferisphaera heterotrophis other marine bacteria dramatically by facilitating nitrogen metabolism. Although genetic analysis of the group suggests Poriferisphaera heterotrophis Containing all the genes necessary for nitrate and ammonia metabolism, chronic infection with this bacteriophage may further improve nitrogen metabolism.

„Our analyzes indicate that the ZRK32 strain is a new species that grows well in nutrient-rich media and releases a bacteriophage in the presence of nitrogen,” concludes senior author Zhaomin Sun, a professor at the Institute of Oceanology of the Chinese Academy of Sciences. and the National Laboratory for Marine Science and Technology. „This phage-ZRK32 is a chronic bacteriophage It lives inside its host without killing it. Our findings provide a new insight into nitrogen metabolism PlanctomyceteA suitable model to study interactions between bacteria and Planctomycetes and viruses.”

Note: “Physiological and metabolic insights into the first domesticated anaerobic representative of the deep sea Planctomycetes Bacteria” Riquan Zheng, Chong Wang, Rui Liu, Ruining Cai and Chamin Sun, 28 Aug 2023, eLife.
DOI: 10.7554/eLife.89874.1