Chapter: Essential Microbiology: Procaryote Diversity
Phylum ‘Deinococcus-Thermus’
Phylum
‘Deinococcus–Thermus’*
Only three genera are included in this phylum, but
two of these are of particular inter-est because of remarkable physiological
properties. Thermus species are
thermophiles whose best known member is T.
aquaticus; this is the source of the thermostable en-zyme Taq polymerase, used in the polymerase
chain reaction. Deinococcus species
show an extraordinary degree of resistance to radiation, due, it seems, to an
un-usually powerful DNA repair system. This also enables Deinococcus to resist chemical mutagens. Both Deinococcus and Thermus
species have an unusual re-finement to the structure of their peptidoglycan,
with ornithine replacing diaminopimelic acid (Figure 7.11).
Representative genera: Deinococcus, Thermus
The remaining phyla of Gram-negative bacteria are
grouped together in Volume 5 of the second edition of Bergey.
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