Study of the growth of Escherichia coli on mixed substrates using dynamic flux balance analysis

Escherichia coli produces acetate as the major by-product when grown in a batch culture medium of glucose under aerobic conditions. The secreted acetate can be used as an additional substrate for cell growth leading to a mixed-substrate growth pattern of diauxic growth. However the acetate formed can limit growth of the organism if found in high amounts in the culture medium and such a scenario necessitates the study of the growth of microorganisms on mixed substrates. Dynamic flux balance analysis has turned out to be a promising tool in capturing such scenarios of growth on mixed substrates. In this study we carry out a dynamic flux balance analysis study of the growth of Escherichia coli in a batch culture medium of glucose and acetate where the organism encounters the presence of mixed substrates. Additionally we have used a detailed metabolic network to describe the process of metabolism in the organism Escherichia coli. DFBA combined with such detailed metabolic networks can open up possibilities of preventing such harmful growth scenarios for biotechnologically useful micro-organisms.