Cell yields of Escherichia coli during anaerobic growth on fumarate and molecular hydrogen

Escherichia coli was grown anaerobically on sodium fumarate and molecular hydrogen or sodium formate in continuous culture. The maximal growth yield and the maintenance coefficient were determined. In a mineral medium a Ymax(fum) value of 6.6 g dry weight per mol fumarate was found. This value increased to 7;5 when casamino acids were present in the medium. From these data and the corresponding Ymax(ATP) values it could be calculated that per mol of fumarate reduced, 0;4 mol of ATP became available for growth. In batch culture a Yfum value of 4.8 g dry weight per mol fumarate was determined.