Division of labour enables Yarrowia lipolytica synthetic consortia to achieve higher growth rates from starch

BACKGROUND: Yarrowia lipolytica is a promising host for a range of biotechnological applications. However, the costs and sustainability of common feedstocks limit the commercial viability of current bioproduction. Consolidated bioprocessing using plant biomass offers a desirable alternative to reduce costs and improve sustainability, though such approaches are often constrained in single-organism systems due to metabolic burden. Here, we have investigated the use of division of labour (DOL) in Y. lipolytica consortia for the degradation of starch, a common component of plant biomass. RESULTS: We engineered a panel of strains expressing α-amylase and/or glucoamylase, with varying promoter and signal peptide combinations. We found that stronger expression led to higher metabolic burden, and that expressing both amylases imposed a greater burden than expressing either enzyme alone. When combining both amylase strains, we found that some consortia could achieve faster growth rates than the equivalent monoculture. The fastest growing consortium identified from the panel was scaled-up into flasks, where the consortium achieved the highest final biomass, although the fastest growth rate was achieved by the α-amylase strain alone. CONCLUSIONS: These findings suggest that DOL is a promising strategy for degrading complex macromolecules in plant biomass, offering a potential route to more sustainable bioprocessing.