Mechanism-Guided Design of Highly Efficient Protein Secretion and Lipid Conversion for Biomanufacturing and Biorefining.

Bacterial protein secretion represents a significant challenge in biotechnology， which is essential for the cost-effective production of therapeutics， enzymes， and other functional proteins. Here， it is demonstrated that proteomics-guided engineering of transcription， translation， secretion， and folding of ligninolytic laccase balances the process， minimizes the toxicity， and enables efficient heterologous secretion with a total protein yield of 13.7 g L. The secretory laccase complements the biochemical limits on lignin depolymerization well in PD630. Further proteomics analysis reveals the mechanisms for the oleaginous phenotype of PD630， where a distinct multiunit fatty acid synthase I drives the carbon partition to storage lipid. The discovery guides the design of efficient lipid conversion from lignin and carbohydrate. The proteomics-guided integration of laccase-secretion and lipid production modules enables a high titer in converting lignin-enriched biorefinery waste to lipid. The fundamental mechanisms， engineering components， and design principle can empower transformative platforms for biomanufacturing and biorefining.