PHYSICAL AND GENETIC-MAP OF THE METHANOBACTERIUM-WOLFEI GENOME AND ITS COMPARISON WITH THE UPDATED GENOMIC MAP OF METHANOBACTERIUM-THERMOAUTOTROPHICUM MARBURG

A physical and genetic map of the chromosome of Methanobacterium wolfe i was constructed by using pulsed-field gel electrophoresis of restric tion fragments generated by digestion with NotI and NheI. The chromoso me was found to be circular and 1,729 kb in size. Twenty-eight genes w ere mapped to specific restriction enzyme fragments by performing hybr idization experiments with gene probes from various Methanobacterium s trains. The genomic map obtained was compared with the updated genomic map of Methanobacterium thermoautotrophicum Marburg. In spite of majo r restriction pattern dissimilarities, the overall genetic organizatio n seemed to be conserved between the genomes of the two strains. In ad dition, the two rRNA operons of strain Marburg were precisely mapped o n the chromosome, and it was shown that they are transcribed in the sa me direction.