CHARACTERIZATION OF A RIBOSOMAL-RNA GENE-CLUSTER FROM CLOSTRIDIUM-TYROBUTYRICUM - PHYLOGENETIC POSITIONING BASED ON THE 16S-NUCLEOTIDE AND 23S-NUCLEOTIDE SEQUENCES

A ribosomal operon of Clostridium tyrobutyricum NIZO strain 51 was clo ned into plasmid vectors and characterized by DNA sequencing of the 16 S rRNA, 23S rRNA and part of the 5S rRNA. The organization of this rib osomal operon of C. tyrobutyricum is similar to that of C. perfringens and Bacillus subtilis. A proposal was made for the processing stems a nd the sites of maturation of 16S and 23S rRNA. The phylogenetic posit ion of C. tyrobutyricum was reconstructed by comparative 16S rRNA and 23S rRNA sequence analyses. Both analysis provided a similar position for C. tyrobutyricum. The 16S rRNA comparisons showed that C. kluyveri and C. ljungdahlii are the closest relatives of C. tyrobutyricum.