Comparative Study of Deoxyribonucleic Acid Homology and Physiological Characteristics of Strains of Peptococcus saccharolyticus

Abstract

Polynucleotide sequence relationships among strains of Peptococcus saccharolyticus were assessed by analysis of deoxyribonucleic acid-deoxyribonucleic acid homo and heteroduplexes with endonuclease S1. The results showed that P. saccharolyticus strains isolated from different subjects form a very tight group, with deoxyribonucleic acid homology levels ranging between 93 and 100%. Physiological tests of 23 strains included 30 different substrates. Results were remarkably uniform. All 23 strains grew better anaerobically with added H₂ and CO₂ than aerobically. However, colony size was greater on blood agar but not Trypticase soy (BBL Microbiology Systems, Cockeysville, Md.)-yeast extract agar with an atmosphere of 4% O₂ with added H₂ and CO₂ than with anaerobic incubation. The data suggest that these strains are sufficiently closely related to justify their inclusion in a single discrete species, but their appropriate generic classification remains to be resolved.