Deinococcus Radiodurans Compiled Notes

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Classification:

Kingdom: Eubacteria

Phylum: Deinococcus- Thermus

Class: Deinococci

Order: Deinococcales

Family: Deinococcaceae

            Genus: Deinococcus Radiodurans

Deinococcus Radiodurans is OBLIGATE AEROBIC*. The formal scientific name is Deinococcus Radiodurans. This name is only 20 years old. The first name was Micrococcus Radiodurans. Deinococcus Radiodurans literally means “strange berry that can withstand radiation.” It is also nick-named “Conan the Bacterium” because of its hardiness. Deinococcus Radiodurans can STAIN EITHER WAY. This means that the lipids in the plasma membrane contain alkylamines*, not the usual phosphoglycolipids*. Deinococcus Radiodurans are Tetrad* forming.The DNA is in stacked loops. Deinococcus radioduran cells do not have a spore, hard capsule, around them. In most bacteria this is what usually resists radiation. Deinococcus radiodurans are able to go without water for a very long time because there is nowhere for the cell to hold water. In other bacteria cells water can be held in the spore. It can survive most anywhere, including toxic waste sites, thermal vent pools found in oceans, ice cores, salty lake beds, and soil very deep in the earth. It can be found anywhere in the world, but it is easier to find in dry places such as deserts.There have also been reports that it has been found in the human stomach. Deinococcus Radiodurans are obligatory heterotroph*.  For reproduction they undergo BINARY FISSION. Under lab conditions Deinococcus Radiodurans are able to reproduce every hour. In nature they are usually dormant because conditions are not ideal. It was discovered in 1956 by A.W. Anderson in a can of meat that had spoiled even after being “sterilized” with radiation. Scientists believe that it is about 2 billion years old. Deinococcus radiodurans have a sort of PINKISH COLOR.

Beneficial properties (ALL POTENTIAL):

It will be able to preserve food.               

There is so much radiation waste in the United States that it can fill 10,000 football fields one yard deep and keep Niagara Falls running for 26 days straight.

Scientists are genetically engineering deinococcus radiodurans to be able to clean up these radioactive sites.

Chemotherapy kills ALL cells, not just the cancer infected cells in our body.

Deinococcus radiodurans will be able to help with with the radiation therapy to repair the DNA in the cells of the human body.

Because of the lethal doses of radiation on Mars, we are not able to send astronauts. 

With the help of deinococcus radiodurans and its resistance to radiation, we will be able to send astronauts.  

If we lost deinococcus radiodurans in the world:

Since its discovery is so recent, we haven’t yet begun to develop its possible uses (though ideas are in the works). In the future, we hope to use it to clean toxic sites. Without deinococcus radiodurans, cleaning these radioactive sites would be very expensive. We also hope to use deinococcus radiodurans in medicines, especially for the side effects of chemotherapy. Without these medicines, chemotherapy patients would suffer immensely.

 The chance of losing deinococcus radiodurans is impossible for they are able to resist very extreme conditions.

State holders do not like the idea of putting something genetically made into the environment. This is keeping the legislative from passing the act to use deinococcus radiodurans for our world. 

DCR is extremely resistant to radioactivity, and it can withstand up to 3 million rads*, while humans can only sustain up to 100 rads (From this information it is said to be 3000 times more resistant to radiation than the E.Coli in our body.)

HOW DNA REPAIRS ITSELF IN DEINOCOCCUS RADIODURANS:

DNA is able to repair itself very easily when broken up by ionizing radiation*, UV lights, and hydrogen peroxide. All of these are damaging to the DNA. The cells of deinococcus radiodurans can keep growing when under constant radiation, and there is no difference in the growth. While the DNA is being repaired the cell can shut itself down. It takes about 12 to 24 hours for the DNA to be repaired in the cell. The protein RecA is most important element in the repairing of DNA. RecA makes copies of other parts of the DNA that are not broken and puts the DNA back together with the copies. Double strand breaks of the DNA can be repaired in Deinococcus Radiodurans.

The cytosolic manganese* and the low concentration of iron in deinococcus radiodurans help protect the proteins. Some of the proteins they protect repair the DNA in the cell. This is why Deincoccus Radiodurans are so resistant because radiation cannot affect the proteins.

ATTEMPTS TO USE DEINOCOCCUS RADIODURANS:           

In the late 1950s and early 1960s, the military tried to use deinococcus radiodurans to develop a vaccine to inoculate soldiers against radiation sickness. This was unsuccessful, because DCR doesn’t protect itself from radiation; it merely repairs itself.

Why is radiation so dangerous?

Most textbooks now say that it is because it damages the DNA.

Radiation is really dangerous because it damages the protein in the cell. The protein is the engine or motor for the cell.

 

*-denotes definitions defined on definitions link