•Microorganism that make nitrogen usable for plants.

•Environment: Can be found in the Southern United States ecosystem, and play a vital part to this ecosystem

•Two types:

•Non-Free living, Free Living

•Live in root nodules, are not free living and require a host.

•Live in soil or in aquatic environments do not require host.

•Food: Absorb Nitrogen as a gas and turn it into Nitrate or Ammonia

•Nitrogen is an essential part of nucleic acids and proteins. Nitrogen fixing bacteria provides essential nitrogen to organism that are not able to produce their own.

•This experiment was conducted to show the importance of nitrogen fixing bacteria in soil and on the roots of plants, and to show how this bacteria converted nitrogen gas to fixed nitrogen that a plant could use.

• In this experiment they compared the ratios of the measured abundance of the isotopes 14 and 15 of Nitrogen, these are the two isotopes of nitrogen that occur naturally in nature.

•They measured the comparison of Nitrogen fixation in T. turnerae cells in a pure culture, bacterial symbionts in the gill of L. pedicellatus, and subcellular domains of bacteria free host tissue.

•They observe the ratio of the ¹⁵N/ ¹⁴N isotopes through light that was quantified in the secondary cyanide ions ¹²C¹⁴N^– and ¹²C¹⁵N^–

•Tissues were visualized my mapping these isotopes.

•The ratio of the naturally occurring isotopes in nature compared with the nitrogen that was being fixed within the nitrogen fixing bacteria was then determined and could be compared. This is where we see the results of the experiment

•Once the ratio was determined it was found that as time increased the ratio of the 15 and 14 isotopes of Nitrogen in the bacteria also increased.

•The increase in this ratio in the bacteria was then related to the natural abundance of Nitrogen and it was found that the Nitrogen in the bacteria increased at growing rates over its natural ratio.

•In the bacteria free host cell there was no increase of nitrogen as time went on. This was because it had none of the bacteria that could convert it to a fixed nitrogen that the cell could use. This shows the importance of Nitrogen Fixing Bacteria.

•Nitrogen Fixing Bacteria are an essential part of the circle of life. It is proven in this experiment that host cells without nitrogen fixing bacteria are unable to take in nitrogen gas and convert it to nitrate or ammonia. This is essential because nitrogen is a key part of building nucleic acids, and proteins. These are some of the fundamental components to the hierarchy of life. This experiment shows how the organisms that had the nitrogen fixing bacteria in them were able to convert more N2 into the fixed nitrogen, there for one can conclude that organisms with this bacteria will be able to survive better than those that do not.