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NONPROTEOBACTERIA - photosynthetic bacteria are found...

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NONPROTEOBACTERIA---GRAM NEGATIVE BACTERIA ---these are only  distant relatives of the gram-negative proteobacteria.  1. Cyanobacteria—these have a blue-green color and resemble algae. They carry out oxygenic  photosynthesis and many of them fix nitrogen. Special cells called heterocysts contain enzymes  that convert nitrogen gas to ammonium ions. Most species grow in water and have gas vacuoles  that allow the cells to float.  Some are unicellular and divide by binary fission. Other forms are colonies and filamentous  forms. Cyanobacteria are believed to have played a big role in bringing oxygen levels up in our  atmosphere and they still add oxygen as well as fixing nitrogen.  2. Purple and Green Photosyntheticd Bacteria--this is not really an independent group. The 
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Unformatted text preview: photosynthetic bacteria are found scattered in various other groups. Purple sulfur bacteria—gamma-proteobacteria Purple nonsulfur bacteria—alpha-proteobacteria Green sulfur bacteria—non-proteobacteria Green nonsulfur bacteria—non-proteobacteria In general, they are mostly anaerobic and live in sediments of lakes and ponds. Shape may be spirals, rods, or cocci. They carry out anoxygenic photosynthesis. The following overall reaction occurs in purple and green sulfur bacteria: 2 H 2 S + CO 2 (CH 2 O) + H 2 O + 2 S Purple and green nonsulfur bacteria reduce CO 2 using organic compounds such as acids or carbohydrates as electron donors....
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