A Bottom-Up Approach To Develop a Synthetic Microbial Community Model: Application for Efficient Reduced-Salt Broad...

Area of Science:

• Food Microbiology
• Fermentation Science
• Synthetic Biology

Background:

• Traditional bean-based fermented foods rely on high salinity for microbial control and flavor development.
• High salinity can inhibit beneficial microbes, reducing fermentation efficiency and posing health risks.
• Developing defined starter cultures for reduced-salt, sterile fermentation is crucial for improving food production.

Purpose of the Study:

• To explore microbial community dynamics and functions in traditional Chinese broad bean paste fermentation.
• To isolate and characterize core microbial species for their salinity tolerance and interactions.
• To reconstruct a synthetic microbial community for efficient, reduced-salt broad bean paste fermentation.

Main Methods:

• Analysis of microbial assembly and function in 12% salinity broad bean paste.
• Isolation and in vitro evaluation of core species' salinity tolerance and metabolic characteristics.
• Reconstruction of a synthetic community using five key strains (Aspergillus oryzae, Bacillus subtilis, Staphylococcus gallinarum, Weissella confusa, Zygosaccharomyces rouxii) under varying salinities.

Main Results:

• Salinity and microbial interactions significantly influenced community dynamics during fermentation.
• Five dominant genera (Staphylococcus, Bacillus, Weissella, Aspergillus, Zygosaccharomyces) were identified as key players.
• A reconstructed synthetic community achieved efficient broad bean paste fermentation in a sterile environment with 6% salinity over 6 weeks.

Conclusions:

• This study provides a bottom-up approach to developing functional microbial consortia for fermented foods.
• Deconstructing and reconstructing microbial communities enables efficient, reduced-salt fermentation.
• The findings support the transformation of traditional food industries towards safer and more efficient practices.