[2S02m] 04. Brewing, Fermentation and Food Technology - Part 1

10:30 AM - 11:00 AM JST(1:30 AM - 2:00 AM UTC)

[2Brew-03] Redefining Fermentation: Synthetic Biology–Driven Breeding of Koji Mold

○Jun-ichi Maruyama¹ (1. The Univ. of Tokyo (Japan))

Keywords:

koji mold,Aspergillus oryzae,synthetic biology,CRISPR/Cas9,genome,fermentation,brewing

The filamentous fungus Aspergillus oryzae (koji mold) is a key microorganism in Japan’s traditional brewing industries, and its importance has been reaffirmed through its role in “traditional sake brewing,” recently inscribed on the UNESCO Intangible Cultural Heritage list. Beyond its long history in fermentation, koji mold is recognized as a versatile platform for the production of enzymes, as well as heterologous proteins and natural products. Since the first whole-genome sequence was reported in 2005, research on koji mold has advanced significantly. However, genetic studies have largely relied on the reference strain RIB40, while industrial strains—diversified and optimized for specific applications—have remained difficult to genetically manipulate. To overcome this limitation, we established genome editing platforms based on the CRISPR/Cas9 system in koji mold. These technologies enable highly efficient gene modification in industrial strains, as well as iterative multiple gene modifications via plasmid recycling. Through large-scale metabolic rewiring, we demonstrated that this genome editing–based strategy can substantially enhance production capacity and unlock the latent potential of koji mold. At the same time, advances in next-generation sequencing have rapidly expanded genomic information across diverse industrial strains. The integration of comparative genomics with precise genome engineering now enables systematic identification of genotype–phenotype relationships and the rational design of strains with desired traits. Furthermore, the ability to perform efficient and versatile genetic modifications directly in industrial strains paves the way for truly industry-oriented breeding of koji mold. Together, these developments mark the advent of synthetic biology–driven breeding in koji mold, enabling the design and optimization of industrial strains with unprecedented precision and driving innovations in fermentation, biotechnology, and future food systems.