Synthesis of adenylate nucleotides by Mollicutes (mycoplasmas).

Abstract

Cultures of the Mollicutes (mycoplasma) Acholeplasma laidlawii B, Acholeplasma morum, Mycoplasma bovis, Mycoplasma arginini, Mycoplasma fermentans and Mycoplasma gallisepticum, representing four metabolic groups, were sampled at intervals over a 40 to 50 h period and assayed for the numbers of c.f.u., changes in pH and glucose concentration, and concentrations of ATP, ADP, AMP, lactate and pyruvate. The adenylate energy charge (ECA), the mean generation time, and the number of nmol of ATP (mg dry weight)-1 were calculated for cultures in the mid-exponential growth phase. The maximum cell concentrations ranged from 0.2 X 10(10) to 5.0 X 10(10) c.f.u. ml-1. Doubling times ranged from 0.34 to 3.29 h. The fermentative, nonarginine-requiring A. laidlawii B, A. morum, and M. gallisepticum, as well as the fermentative, arginine-requiring M. fermentans, utilized glucose and produced lactate and pyruvate. The non-fermentative, non-arginine-requiring M. bovis neither utilized glucose nor produced lactate or pyruvate. The non-fermentative, arginine-requiring M. arginini utilized glucose, but did not produce lactate or pyruvate. At mid-exponential growth phase, the average ECA of A. laidlawii B was 0.90, a value similar to that reported for Spiroplasma citri and other bacteria. In contrast, the average ECA of A. morum and the four Mycoplasma species was 0.70. In A. laidlawii B at mid-exponential growth phase, ATP accounted for 97% of the total adenylate nucleotide pool.(ABSTRACT TRUNCATED AT 250 WORDS)