The utilisation of glucose/acetate mixtures by Escherichia coli W3110 under aerobic growth conditions

Byproduct acetate is of major concern when considering the growth of Escher ichia coli on glucose. Besides the fact that acetate production detracts fr om the overall yield, acetate itself is also a growth inhibitor. To further complicate matters, E. coli is capable of growth on acetate via the glyoxy late bypass. In an effort to evaluate the influence of acetate on the growt h of E. coli, mixed glucose/acetate substrate batch and continuous cultivat ions have been carried out. The results have been examined in the context o f their implications for industrial-scale bioreactors. It was found that ac etate was growth inhibitory at relatively low concentrations <1.25 g/l. A b atch culture supplied with both glucose and acetate utilised glucose in pre ference to acetate. Simultaneous utilisation of substrates was observed in continuous cultures at low imposed growth rates, i.e., below ca. 0.30 h(-1) .