CHARACTERIZATION OF A PLASMID CARRIED BY METHANOBACTERIUM-THERMOAUTOTROPHICUM ZH3, A METHANOGEN CLOSELY-RELATED TO METHANOBACTERIUM-THERMOAUTOTROPHICUM MARBURG
R. Stettler et al., CHARACTERIZATION OF A PLASMID CARRIED BY METHANOBACTERIUM-THERMOAUTOTROPHICUM ZH3, A METHANOGEN CLOSELY-RELATED TO METHANOBACTERIUM-THERMOAUTOTROPHICUM MARBURG, Systematic and applied microbiology, 17(4), 1995, pp. 484-491
Strain ZH3, a hydrogenotrophic, thermophilic methanogenic archaeon was
isolated from a sewage sludge digester. Based on its phenotypic prope
rties and its 16S rRNA sequence (99.9% similarity), strain ZH3 is clos
ely related to Methanobacterium thermoautotrophicum Marburg. The newly
isolated organism harbored pME2200, a cryptic 6.2 kb plasmid, which i
s related to, but not identical with the previously characterized cryp
tic 4.4 kb plasmid pME2001 of strain Marburg. Plasmid pME2200 was char
acterized by restriction mapping and by Southern blot and DNA sequence
analysis and compared to plasmid pME2001. The two elements are compos
ed of a presumably identical, 3.8 kb backbone structure. In addition t
o the common backbone, both plasmids carry a region of high interplasm
id homology, which in pME2200 was interspersed with three segments not
present in pME2001. These interspersed segments did not encode potent
ial open reading frames. One of them contained a singular restriction
site which may be of use for the construction of potential cloning vec
tors that are undamaged in essential plasmid functions.