Phylum Aquificae and phylum Thermotogae the deeply branching bacteria

These two phyla are regarded as the two deepest (= oldest) branches in the evolution of the Bacteria and both comprise highly thermophilic Gram-negative rods. They are the only members of the Bacteria that can compare with the Archaea in their ability to live at high temperatures (optimal growth >80°C). The two phyla differ in their mode of nutrition: the Aquificae are autotrophs capable of oxidising hydrogen or sulphur, while the Thermotogae are anaerobic heterotrophs, fermenting carbohydrates.


(a) Diaminopimelic acid (b) Ornithine

Figure 7.11 Members of the Deinococcus-Thermus group have an unusual form of pep-tidoglycan. The diaminopimelic acid at position three on the amino acid chain attached to N-acetylmuramic acid (see Figure 3.6) is replaced by ornithine

Members of the Thermotogae are characteristically surrounded, sometimes in a chain, by a proteinaceous sheath (or 'toga').

Representative genera: Aquifex (phylum Aquificae), Thermotoga (phylum Thermoto-gae)

Was this article helpful?

0 0
Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

Get My Free Ebook

Post a comment