Before revision:  Here, we apply the disparity filter method based on a high-flux fluctuation analysis to extract the metabolic backbones of two URLanisms, Escherichia coli and Mycoplasma pneumoniae, using computationally predicted fluxes that maximize their growth rate .
After revision:  Here, we disclose the metabolic backbone of Escherichia coli using computationally predicted fluxes that maximize their growth rate .