Computational assessment of lipid production in Rhodosporidium toruloides in two‐stage and one‐stage batch bioprocesses

Abstract

Oleaginous yeasts are promising platforms for microbial lipids production as arenewable and sustainable alternative to vegetable oils in biodiesel production. Inthis paper, a thorough in silico assessment of lipid production in batch cultivation byRhodosporidium toruloides was developed. By means of dynamic flux balanceanalysis, the traditional two‐stage bioprocess (TSB) performed by the native strainwas contrasted with one‐stage bioprocess (OSB) using four designed strainsobtained by gene knockout strategies. Lipid titer, yield, content, and productivitywere analyzed at different initial C/N ratios as relevant performance indicators usedin bioprocesses. By weighting these indicators, a global lipid efficiency metric (GLEM)was defined to consider different scenarios. Under simulated conditions, designedstrains for lipid overproduction in OSB outperformed the TSB in terms of lipid title(up to threefold), lipid yield (up to 2.4‐fold), lipid content (up to 2.8‐fold, with amaximum of 76%), and productivity (up to 1.3‐fold), depending on C/N ratios. Usingthese efficiency parameters and the proposed GLEM, the process of selecting themost suitable candidates for lipid production could be carried out beforeexperimental assays. This methodology holds the potential to be extended to otheroleaginous microorganisms and diverse strain design techniques.