Predicting metabolic pathways and microbial interactions in dark fermentation systems treating real cheese whey...

Area of Science:

• Microbiology
• Biotechnology
• Environmental Science

Background:

• Dark fermentation offers a sustainable route for valorizing agro-industrial waste.
• Complex microbial dynamics in these processes hinder optimization.
• Cheese whey is a viable substrate for biohydrogen production.

Purpose of the Study:

• To investigate microbial communities and metabolic interactions during continuous hydrogen production from cheese whey.
• To elucidate the functional roles of key genera using PICRUSt2.
• To understand factors influencing microbial dynamics for process optimization.

Main Methods:

• Continuous dark fermentation of cheese whey and fermented cheese whey.
• Microbial community analysis using functional profiling with PICRUSt2.
• Metabolic pathway reconstruction and analysis.

Main Results:

• Lactobacillus genera were identified as primary consumers of carbohydrates and producers of lactate.
• A competitive dynamic between Clostridium sensu stricto 12 and Caproiciproducens for lactate utilization was observed.
• Clostridium sensu stricto 12 was identified as the main hydrogen producer via electron bifurcation, while Caproiciproducens may use alternative energy mechanisms.

Conclusions:

• Functional profiling with PICRUSt2 is effective for understanding microbial interactions in dark fermentation.
• Optimizing biohydrogen production requires a deep understanding of microbial consortia and their metabolic interplay.
• Substrate availability and process conditions significantly influence microbial community structure and function.