Abundance-stratified microbial succession underlies functional stability in traditional solid-state fermentation

Area of Science:

• Microbiology
• Industrial Biotechnology
• Food Science

Background:

• Solid-state fermentation (SSF) is crucial for baijiu production but faces challenges from environmental instability.
• Maintaining functional stability in multi-round SSF despite disturbances is a key industrial concern.

Purpose of the Study:

• To investigate the microbial ecotype-relay mechanism sustaining functional stability in multi-round Jiang-flavor Baijiu SSF.
• To correlate microbial community dynamics with physicochemical changes and functional roles across fermentation rounds.

Main Methods:

• Coordinated industrial fermentation across 17 distilleries using a unified seven-round scheme.
• Integrated analysis of microbial community profiling, physicochemical parameters, niche width, functional prediction, and acid-tolerance assays.

Main Results:

• Distinct microbial ecotype succession observed across fermentation rounds, linked to physicochemical shifts (acidification, substrate depletion).
• Abundant taxa dominated early rounds (metabolism), moderate taxa thrived mid-rounds (transport, stress), and rare taxa expanded late-rounds (sensing, regulation).
• Acid tolerance assays confirmed ecotype-specific adaptations, supporting the relay mechanism.

Conclusions:

• An ecotype-relay mechanism, driven by abundance-stratified microbial succession, underpins functional stability in multi-round baijiu SSF.
• Round-specific microbial management strategies can enhance stability and quality in industrial baijiu production.