NUCLEIC ACID CONTENT OF PLEUROPNEUMONIALIKE ORGANISMS FROM HUMAN SOURCES

Abstract

Nucleic acids make up approximately 4 to 5% of the total dry weight of the cell of pleuropneumoniallike organisms. The nucleic acid P represents approximately 48% of the total P of the cell. Forty-hour-old cells from an optimal growing lipuid culture showed a pentose nucleic acid to deoxypentose nucleic acid ratio of 2, whereas with cells obtained from liquid cultures showing poor growth this ratio was 1 or less. The deoxypentose nucleic acid fraction contained 13% more of the bases adenine and thymine than it did guanine and cytosine. No 5-hydroxy-methyl cytosine was detected in the deoxypentose nucleic acid portion of this organism. In the pentose nucleic acid fraction the bases guanine and cytosine were detected in greater quantity than adenine and thymine. The maximal concentration of nucleic acid material as measured by the ratio of UV absorption at 260 m[mu] to turbidity was found at the end of a 12 hour lag phase of growth.