Microbe of the Month
The HHMI film How Giant Tube Worms Survive at Hydrothermal Vents is one of 12 have a symbiotic relationship with species of chemosynthetic bacteria. During chemosynthesis, bacteria living on the sea floor or within animals use energy In the diagram mussels and tubeworms are using the hydrogen sulfide . In some symbiotic relationships, one of the organisms benefits but the other is between microbes and a wide range of animals including corals, tubeworms, and in clams and mussels that have chemosynthetic bacteria living in association.
Instead of eating food like other animals, Riftia allows bacteria to live inside of it and provide its food.
You Feed Me, I Feed You: Symbiosis - Dive & Discover
The worms have a special feeding sac, called a trophosomewhich provides the bacteria with shelter and ingredients to make food. In turn, the bacteria use these ingredients to make food for the worm. The trophosome and the bacteria inside it are so important that they make up over half the weight of this animal.
Strange Life in the Dark Dark ocean floors near deep sea vents are home to giant clams, shrimps, tube worms, crabs and other strange creatures. When these communities were first discovered living deep on the dark ocean floor, no one know how life could exist there without sunlight. Until recently, people thought that all food ultimately comes from plants and other photosynthetic creatures like algae and cyanobacteria.
These photosynthesizers use energy from sunlight to convert carbon dioxide into food. Organisms that make food for an entire community are called primary producers. But who are the primary producers deep under water where there is no light?
These bacteria, like the ones in the picture above, get their energy from chemicals flowing out of the volcanic vents, not from energy found in sunlight. Hydrogen sulfide, the stuff that smells like rotting eggs and is toxic to us, is one of the main chemicals used by the vent bacteria for making food. These bacteria make energy by combining hydrogen sulfide with oxygen also supplied by the tube worms to make sulfur, water and energy. The bacteria then uses this energy to convert carbon dioxide into food just like plants use energy from the sun to make food.
Photosynthesis and chemosynthesis
This food in turn feeds the entire community of worms, clams, crabs and other creatures. In the case of the tube worm, the bacteria living inside the worm use the hydrogen sulfide supplied by the worm. The worm collects the hydrogen sulfide with its red feathery cap. This cap is red because it is filled with blood containing a special hemoglobin that transports the hydrogen sulfide to the bacteria.
The tubeworm also provides the symbionts with oxygen which it needs to combine with the hydrogen sulfide for energy. This oxygen comes from the ocean surface.
The tube worm provides the perfect place for bacteria to get both oxygen and hydogen sulfide which are often difficult to find in one place.
Photosynthesis and chemosynthesis – Sea floor – Te Ara Encyclopedia of New Zealand
Sunlight cannot penetrate into the deep ocean, so the organisms that live there cannot do photosynthesis. They must rely on a different source of energy. At cold seeps and hydrothermal vents, there are many chemicals that microbes can use to create food and energy. Hydrogen sulfide the stuff that smells like rotten eggs and methane are two of the most common of these.
Where hydrogen sulfide is present in the seafloor around cold seeps, tubeworms are often found growing in clusters of thousands of individuals. These unusual animals do not have a mouth, stomach, or gut.Marine Tube Worms amazing appearing and quick disappearing act. DON'T BLINK!
Instead, they have a large organ called a trophosome that contains billions of chemosynthetic bacteria. In some cases, the trophosome accounts for more than half the weight of the tubeworm. The bacteria then use these materials plus carbon dioxide they take from the water to produce organic molecules. A similar symbiotic relationship is found in clams and mussels that have chemosynthetic bacteria living in association with their gills.
A variety of other organisms found in cold seep communities also use tubeworms, mussels, and hard and soft corals as sources of food or shelter or both. They include snails, eels, sea stars, crabs, lobsters, isopods, sea cucumbers, and fishes. Some of these might be symbiotic interactions, but the specific relationships between these organisms and the other animals living around cold seeps have not been well studied. Microscopic Mutualism Mutualistic symbiosis also occurs between protists and bacteria or archaea, especially those that live in extreme environments.
Protists are single-celled eukaryotes such as diatoms, foraminifera, and ciliates. Eukaryotic cells have a nucleus and other organelles surrounded by a membrane. Plants, fungi, and animals are also eukaryotes. Bacteria and archaea are prokaryotes, which are single-celled organisms that do not have a nucleus or other organelles surrounded by a membrane.
DHABs are among the most extreme environments on Earth. Organisms living there face complete darkness, up to ten times the salinity of normal seawater, complete lack of oxygen, very high pressure, and in some cases, high levels of sulfide or methane, both of which are toxic for most eukaryotes, including protists.
All of the protists that have been collected from DHABs have bacteria closely associated with them.
Some are completely covered with bacteria. Others have bacteria inside their single-celled body, enclosed in a membrane.