Deoxyribonucleic acid studies in the genus Caryophanon

Abstract

The deoxyribonucleic acid (DNA) of 36 isolates of Caryophanon latum and 3 isolates designated Caryophanon tenue, obtained from geographically diverse regions, has been examined for guanine plus cytosine (mol % G+C) base composition, genome size, and for relative reassociation levels. The isolates were found to be homogenous and group-specific in their base composition, with C. latum DNA ranging from 44.0 to 45.6 mol % G+C, and C. tenue from 41.2 to 41.6 mol % G+C. Genome size determined for representative isolates confirmed the distinction of the two groups. The genome size ranged from 1100 to 1200 X 10(6) daltons for C. latum and from 900 to 1000 X 10(6) daltons for C. tenue. DNA:DNA hybridization studies revealed relative reassociation levels as follows: C. latum to C. latum, 78-94%, C. tenue to C. tenue, 82-94%; and C. latum to C. tenue, 13-30%. Finally, based on genome size and mol % G+C similarities, DNA:DNA hybridization experiments between two strains of Lactobacillus and C. latum and C. tenue were performed. These experiments revealed essentially no polynucleotide sequence similarity between the Lactobacillus and Caryophanon isolates used.