Evolution at the speed of fermentation

Precision fermentation promises to transform the food supply, but achieving cost parity with traditional production requires unprecedented protein titers. Unlike pharmaceutical proteins, food proteins demand exceptionally high yields, making strain optimization critical. Aspergillus oryzae, optimized over decades, provides a robust platform for milk protein expression, including beta-lactoglobulin (BLG). Rational strain engineering and adaptive laboratory evolution accelerate titer improvements, resembling traditional koji fermentation, where domestication of A. oryzae selected strains with enhanced amylolytic activity and faster growth. Domestication - including transposon and amylase gene expansion - highlight similarities between historical and modern strain optimization. We describe BLG strain optimization and discuss how mimicking domestication principles may fast-track strain improvement. We discuss recent advances and challenges in scaling precision fermentation to supply affordable, nutritious proteins. Our work on BLG illustrates how industrial biotechnology is reaching cost parity with dairy, underscoring the potential of evolution - natural and engineered - at the speed of fermentation.