Scientists discovered a brand new type of bacteria living inside coral from the ocean. This bacterium, named Carbonatibacter coralli, is special because it produces carbonate (a chalky substance) and shares vitamin B12 with other organisms around it. Researchers studied its genes, structure, and chemical makeup to confirm it’s completely different from other known bacteria. This discovery helps us understand the tiny organisms that live in coral reefs and how they work together to keep the ocean ecosystem healthy. The findings were published in a scientific journal that focuses on classifying and studying different types of microorganisms.

The Quick Take

  • What they studied: Scientists wanted to identify and classify a new bacterium they found living inside coral from the ocean, and understand how it’s different from other known bacteria.
  • Who participated: Researchers isolated and studied one strain of bacteria (called GXU_MW_B19T) collected from Porites lutea coral. The study involved laboratory analysis of this single bacterial sample using multiple scientific techniques.
  • Key finding: The new bacterium is so different from other known bacteria that scientists created an entirely new genus (family group) to classify it. It shares only about 69.5% of its genetic material with its closest relatives, making it distinct enough to be considered a brand new species.
  • What it means for you: This discovery helps scientists better understand the invisible world of bacteria living in coral reefs. While this specific bacterium won’t directly affect your daily life, understanding coral ecosystems is important for protecting ocean health, which ultimately affects all of us. This research is primarily of interest to marine biologists and microbiologists.

The Research Details

Scientists collected a sample from coral and isolated a single bacterium strain in their laboratory. They then performed multiple tests to identify and classify this bacterium. First, they looked at the bacterium’s genes (specifically a part called 16S rRNA) and compared them to genes from other known bacteria. They also sequenced the entire genome (all the genetic instructions) of the new bacterium and compared it to related species. Additionally, they examined the bacterium’s physical characteristics, like what temperature and salt levels it could survive in, what chemicals made up its cell walls, and what proteins it could produce.

The researchers used advanced genetic analysis techniques to create family trees showing how this new bacterium relates to other microorganisms. They measured the similarity between the new bacterium’s genes and those of known bacteria to determine if it was truly a new species. They also studied the fatty acids and lipids (fatty molecules) that make up the bacterium’s cell structure, which is like looking at the building blocks of the cell.

Based on all these different types of evidence—genetic, physical, and chemical—the scientists concluded that this bacterium was so different from anything previously known that it deserved its own new genus (a higher level of classification). This is similar to how scientists might discover a completely new animal species that doesn’t fit into any existing animal families.

Using multiple different methods to identify bacteria is important because it gives scientists confidence in their conclusions. By looking at genes, physical traits, and chemical makeup all together, researchers can be sure they’ve truly found something new rather than just a variation of something already known. This thorough approach is especially important when classifying microorganisms, which are too small to see without a microscope and can be tricky to tell apart.

This study was published in a peer-reviewed scientific journal, meaning other experts reviewed the work before publication. The researchers used internationally recognized methods for bacterial classification and compared their findings to established databases of known bacteria. The study included detailed genetic sequencing and analysis, which is the gold standard for identifying new microorganisms. However, the study focused on just one bacterial strain, so the findings describe this specific bacterium rather than making broad claims about all bacteria in coral.

What the Results Show

The new bacterium, named Carbonatibacter coralli, was found to be genetically distinct from all previously known bacteria. When scientists compared its genes to the closest known relatives, the similarity was only about 69.5% at the genetic level and 62.8% at the protein level—far below the threshold for being considered the same species. The bacterium could survive in temperatures between 20-40°C (68-104°F), in water with varying acidity levels (pH 6.5-10), and in salt water with up to 5% salt concentration.

The bacterium has a unique set of proteins and enzymes that other related bacteria don’t have. These include special enzymes that break down certain sugars and help with phosphate processing, as well as proteins related to viral defense mechanisms. The bacterium’s cell wall is made up of specific fatty acids and lipids that are different from its closest relatives, further confirming it’s a new species.

Based on genetic family tree analysis, the new bacterium belongs to a group called Rhodospirillales, but it’s different enough that scientists created a new genus (Carbonatibacter) to classify it. The bacterium’s genome (its complete set of genetic instructions) is 54.5% GC content, which is a measure of the genetic material composition.

The discovery also led scientists to reorganize how they classify related bacteria, reclassifying the Kiloniellaceae family and creating a new family called Aestuariispiraceae to better reflect the relationships between different bacterial groups.

The bacterium produces carbonate, which is the same chalky substance found in seashells and limestone. This carbonate-producing ability may play a role in the coral’s calcium carbonate skeleton. Additionally, the bacterium appears to share vitamin B12 with other organisms in the coral, suggesting it plays a role in the complex community of microorganisms living within the coral. These characteristics suggest the bacterium has specific ecological roles within the coral holobiont (the coral and all its associated microorganisms functioning as one unit).

This discovery adds to our growing understanding that coral reefs host incredibly diverse microbial communities. Previous research has shown that corals depend on bacteria for various functions, including nutrient cycling and disease resistance. This new bacterium represents another piece of the puzzle in understanding how these microscopic communities support coral health. The reclassification of related bacterial families also helps scientists better organize and understand the evolutionary relationships between different microorganisms.

This study identified and characterized only a single bacterial strain, so the findings describe this specific bacterium rather than all bacteria of this type. The research was conducted in a laboratory setting, so it doesn’t tell us exactly how this bacterium functions within the living coral in its natural ocean environment. The study doesn’t include long-term observations of how this bacterium interacts with the coral or other microorganisms over time. Additionally, while the genetic and chemical analysis is thorough, the study is primarily descriptive—it identifies and classifies the bacterium but doesn’t extensively explore what roles it plays in the coral ecosystem.

The Bottom Line

This research doesn’t lead to direct health recommendations for people. However, it supports the broader scientific recommendation to protect coral reef ecosystems, as they depend on complex microbial communities like this newly discovered bacterium. For marine scientists and microbiologists, this work provides a new framework for classifying and studying related bacteria. The confidence level in the classification is high, based on multiple lines of genetic and chemical evidence.

Marine biologists, microbiologists, and scientists studying coral reef ecosystems should find this research valuable. Ocean conservation advocates and environmental policymakers may be interested in how this discovery highlights the complexity of coral ecosystems. The general public should care about coral reef health, as these ecosystems support marine life and provide benefits to humans. However, this specific bacterium won’t directly affect most people’s daily lives or health decisions.

This is a foundational discovery rather than a treatment or intervention, so there’s no timeline for personal benefits. However, understanding coral microbiomes may eventually help scientists develop better strategies to protect coral reefs from disease and climate change impacts—benefits that could take years or decades to realize.

Want to Apply This Research?

  • While this research doesn’t apply to personal health tracking, users interested in ocean conservation could track their coral reef protection activities, such as reef-safe sunscreen usage, ocean plastic cleanup participation, or donations to coral conservation organizations.
  • Users could use the app to learn about and commit to coral-friendly behaviors, such as choosing reef-safe products, reducing carbon footprint to combat ocean acidification, or supporting marine conservation efforts. The app could provide educational content about coral microbiomes and why protecting coral ecosystems matters.
  • Long-term tracking could include monitoring personal contributions to coral conservation, tracking educational milestones about ocean health, or following updates on coral reef research and protection efforts. Users could set goals related to ocean sustainability and track their progress over time.

This research describes the discovery and classification of a new bacterium found in coral and does not provide medical advice or health recommendations for human use. The findings are of scientific and educational interest for understanding marine ecosystems. This bacterium has not been studied for any effects on human health, and no conclusions should be drawn about its safety or use in any human applications. If you have questions about coral conservation or marine science, consult with marine biologists or environmental scientists. This summary is for educational purposes and should not replace consultation with qualified scientific experts for research interpretation.