Food grade microbial synthesis of the butter aroma compound butanedione using engineered and non-engineered Lactococcus lactis

The design-build-test-learn (DBTL) cycle has been implemented in metabolic engineering processes for optimizing the production of valuable compounds, including food ingredients. However, use recombinant microorganisms producing ingredients is associated with different challenges, e.g., EU, a content more than 0.9% such requires to be labeled. Therefore, we propose expand DBTL and “learn” module guide development non-engineered strains clean label production. Here, demonstrate how this approach can used generate engineered natural cell factories able produce flavor compound - butanedione (diacetyl). Through comprehensive rerouting metabolism Lactococcus lactis MG1363 re-installment capacity metabolize lactose dairy protein, managed achieve high titer diacetyl (6.7 g/L) pure waste. Based on learnings from efforts, successfully achieved without using DNA technology. We accomplish latter by process optimization relying high-throughput screening microfluidic system. Our results great potential that lies combining approaches achieving efficient