Relatedness of Strains ΔH and Marburg of Methanobacterium thermoautotrophicum

Methanobacterium thermoautotrophicum ΔH and M. thermoautotrophicum Marburg have been investigated for DNA relatedness by DNA-DNA hybridization. The two strains proved to be interrelated on the 46% binding level. The relatively low degree of DNA homology correlated with differences in biochemical and physiological characteristics:

• 1.

  The pseudomurein sacculus of the ΔH strain contained glucosamine and talosaminuronic acid as major sugar components, whereas the sacculus of the Marburg strain contained galactosamine and talosominuronic acid.

• 2.

  One of the eight subunits of the DNA dependent RNA polymerase differed considerably with respect to molecular weight.

• 3.

  The membrane fraction of the ΔH strain exhibited high ATPase activity, which could not be detected in the Marburg strain.

• 4.

  The Marburg strain grew more rapidly (td = 1.6 h versus 2.2 h) and to a higher cell density than the ΔH strain.