Inflammation feeds E. coli

Tina Hesman Saey, Science News
Published 7 February 2013
http://www.sciencenews.org/view/generic/id/348117/description/Inflammation_feeds_E_coli

Summary
A new study shows that inflamed intestines produce compounds that nourish E. coli and other disease related bacteria. A small amount of E. coli is present in everyone's intestines, but people with inflammatory bowel diseases such as ulcerative cloitis have a higher composition of it. The study shows that inflammation, a process the body uses to kill microbes, may "feed" the harmful bacteria, such as E. coli, causing more inflammation in the gut. During inflammation, chemicals are produced that can break DNA and destroy bacteria. But in experiments done on mice, scientists have discovered that the chemicals reacting with each other can produce nitrates and other compounds that some bacteria use as fuel. E. coli normally make up about 0.1% of bacteria in the gut, but E. coli in an inflamed colon can grow to make up about 10% of the microbes in the intestine. To find out how this happens, scientists injected a chemical into mice to inflame their bowels. They found that the inflamed bowels produce nitrate, which most bacteria in the gut cannot consume. However, E. coli and its close relatives can. They have enzymes that break down nitrates and other chemicals for energy. The E. coli have a huge competitive advantage over other microbes because of their ability to use the nitrates, which helps them out compete other bacteria during inflammation. The experiment also showed that mice with normal colons and mice that had an enzyme that produces nitric oxide, the precursor to nitrate, blocked, did not have an overgrowth of E. coli. The results of the experiment suggest that removing inflammation generated nitrate or blocking E. coli's ability to use it could limit its growth in intestines. Unfortunately, nitric oxide has important functions throughout the body, such as regulating blood vessel dilation, so blocking the enzyme that produces it may not be a good way to treat bowel diseases. Scientists are working on potential treatments that would prevent E. coli and related bacteria from using nitrate, while keeping a stable microbial mix in the intestines.

Connection
This article connects to the microbes unit because E. coli is a type of bacteria, and bacteria are microbes. We also did a lab testing E. coli growth.

How the Ocean Loses Nitrogen

How the Ocean Loses Nitrogen: Scientists Identify Key Factor That Controls Nitrogen Availibilty In the Ocean

Feb. 24, 2013
Tim Kalvelage
http://www.sciencedaily.com/releases/2013/02/130224142723.htm

Summary: 
Recently a group of scientists from Institute for Marine Microbiology in Bremen and also some from the company GEOMAR went to the South Pacific Ocean and they found some interesting data. They concluded that decaying algae controls nitrogen loss from the ocean. The ocean is rapidly filling with more nitrogen then normal. This means there is less oxygen and the nitrogen gas from the ocean is then escaping into the atmosphere which can contribute to global warming. Also, the lack of oxygen and increase of nitrogen in the ocean could change what lives in the ocean. We could see in the coming years, the increase in populations of organisms which live in the none/minimal oxygen zones of the ocean. Anaerobic bacteria converts the fixed nitrogen in the ocean to nitrogen gas which is released into the atmosphere by processes such as denitrification and anammox. 

Connection: This discovery connects to our study of microbes and also the nitrogen cycle. Microbes in the water fix the nitrogen. Then, anaerobic bacteria take the fixed nitrogen and convert it into nitrogen gas which can then exit the ocean and be released into the atmosphere. The ocean is a one of the major nitrogen holders which we talked about earlier in the year. Once the nitrogen is released into the atmosphere it could contribute to our problem of global warming. Also, this story connects to adaption because the sea organisms will have to adapt to a changing ocean environment. There will probably be an increase of anaerobic organisms in the ocean as more nitrogen fills the ocean.

Microbes Team Up to Boost Plants' Stress Tolerance

Feb 17, 2013
http://www.sciencedaily.com/releases/2013/02/130217134321.htm

Summary:
Microbes can improve the hardiness of plants, which could lead to more sustainable agriculture, especially since global warming, city growth, and population growth put strain on sustainable agriculture. Marilyn Roossinck, professor of plant pathology and environmental microbiology and biology, and her colleagues found an example of plants and viruses working together to increase drought tolerance. Four different viruses and several different plants were tested. A common weed, lamb's quarter, was infected with a virus that caused a local infection, which actually boosted the plant's drought tolerance. In Yellowstone National Park, viruses and fungi collaborate to increase temperature hardiness. For example, tropical panic grass and fungi can grow together in temperatures above 125 degrees Fahrenheit, but die separated at the same heat levels. Similar to the fungi, a virus infecting a plant fungus made the plant resistant to increased heat. When the virus was cured from the plant fungus, the plant lost thermal tolerance; however, when the virus was reintroduced, the plant regained thermal tolerance. This research, and future research, may help the agricultural industry by developing hardier plants naturally, rather than relying on harmful chemicals.

Connection:
This article connects to our unit on microbes, because the article discusses plant fungi that help the plant grow. This means that the fungi is a mycorrhizal fungi, since it shares a symbiotic relationship with the plant. The article also connects to the Microbes unit because it shows how each partner needs the other, since the tropical panic grass and fungi together can resist heat, but separately will die.