Adenylate energy charge in Acholeplasma laidlawii

Abstract

Adenosine 5'-triphosphate, adenosine 5'-diphosphate, and adenosine 5'-monophosphate were produced by A. laidlawii B-PG9 growing in modified Edward medium. The adenylate energy charge was calculated to be 0.84 ± 0.07 and ranged from 0.91 to 0.78 during exponential growth (12 to 24 h). During exponential growth, A. laidlawii contained, at 17.5 h, 2.3 x 10 -17 mol of adenosine 5'-triphosphate per colony-forming unit and, at 16 h, 27.3 nmol of adenosine 5'-triphosphate per mg (dry weight). The medium supported a doubling time of 0.95 h. The molar growth yields (Y(glucose) = grams [dry weight] per mole of glucose used) were 40.2 ± 3.4 (16 h) and 57.1 ± 9.7 (20 h) during midexponential growth. A maximum yield of 8.3 x 109 colony-forming units was reached at 24 h, when 56% of the initial concentration of glucose had been used. At 40 h, during the stationary phase, 14.95 ± 3.75 μmol of glucose per ml of medium had been used. At this time, the culture fluids contained 21.86 ± 0.37 μmol of lactate per ml and 3.14 ± 0.13 μmol of pyruvate per ml.