MBIO 3470 Lecture Notes - Lecture 19: Bacteriochlorophyll, Proteobacteria, Succinic Acid
2 Mar 2018
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Berge(cid:455)"s places all the ano(cid:454)(cid:455)genic phototrophs into group 10, however, this groups is polyphyletic and 16s rdna analysis shows the anoxygenic phototrophs belong to 3 different phyla. A small phylum representing the most ancient (deepest branching) lineage of phototrophs and likely represents closest descendants of the first organisms to carry out photosynthesis with chlorophyll. The best studied representative is chloroflexus aurantiacus (filaments that are motile by gliding; ~600 um/min) Thermophiles with optimal temperature of growth ~55 degrees celsius, a trait that is thought to be inherited from primordial hyperthermophiles. Habitat: hot springs, freshwater and marine waters, soil. Primarily photoorganoheterotrophs: atp generated from light energy is used to assimilate organic substrates into cell material. They carry out anoxygenic photosynthesis: without releasing oxygen. Chloroflexus aurantiacus is able to grow aerobically. Several genera in this phylum are obligate aerobic chemoheterotrophs that have presumably lost the ability to grow photosynthetically: herpetosiphon (filamentous gliders, thermomicrobium (rods)
