New microbial resource: microbial diversity, function and dynamics in Chinese liquor starter

Area of Science:

• Microbiology
• Fermentation Science
• Food Science

Background:

• Traditional Chinese liquor (Baijiu) production relies on solid-state fermentation for millennia.
• The microbial communities within Baijiu starters are vital for fermentation but remain under-characterized.
• Understanding these microbial ecosystems is essential for optimizing Baijiu production and exploring new applications.

Purpose of the Study:

• To comprehensively analyze the microbial diversity, function, and dynamics of Jiang- and Nong-flavor Baijiu starters.
• To identify key microbial players involved in ethanol fermentation, saccharification, and flavor development.
• To explore the potential of these starters as a resource for novel enzymes and preservation agents.

Main Methods:

• Utilized 454 pyrosequencing technology to profile microbial communities.
• Analyzed bacterial and fungal genera in Jiang- and Nong-flavor starters.
• Employed correlation-based network analysis to identify core microbial communities and their functions.
• Predicted functional profiles of bacterial communities using bioinformatics tools.

Main Results:

• Identified 315 bacterial and 72 fungal genera in Jiang-flavor starters, and 83 bacterial and 47 fungal genera in Nong-flavor starters.
• Observed increased microbial diversity at elevated temperatures (70°C for Jiang-flavor, 62°C for Nong-flavor).
• Discovered thermophilic fungi and identified core microbial communities linked to fermentation and flavor.
• Found significant differences in metabolic pathways between the two starter types, including energy, carbohydrate, amino acid metabolism, and aromatic compound degradation.

Conclusions:

• Baijiu starters represent a rich source of microbial diversity with significant functional roles in fermentation.
• These starters harbor unique microbial communities that can be leveraged for discovering thermophilic enzymes.
• The identified microbes offer potential applications in food and feed preservation and the development of novel fermented products.