Carbon source shaped microbial ecology, metabolism and performance in denitrification systems

Area of Science:

• Environmental microbiology
• Bioreactor engineering
• Metabolic pathway analysis

Background:

• Limited understanding of microbial interactions and metabolic patterns in denitrification systems hinders optimization.
• The influence of diverse carbon sources on these systems remains underexplored.

Purpose of the Study:

• To investigate denitrification performance, metabolic patterns, and ecological structures in bioreactors using four distinct carbon sources.
• To establish linkages between microscale microbial dynamics and macroscale reactor efficiency.

Main Methods:

• Parallel, well-controlled bioreactors were utilized with methanol, glycerol, acetate, and glucose as carbon sources.
• Long-term acclimation allowed for observation of system responses.
• Denitrification rates, organic utilization, heterotrophic bacterial yields, microbial community structure, and metabolic patterns were analyzed.

Main Results:

• Significant differences in denitrification rates, organic utilization, and bacterial yields were observed across the four carbon sources.
• Distinct microbial ecological structures and metabolic patterns emerged depending on the carbon source.
• Methanol-fed reactors exhibited unique carbon utilization pathways and a more complex microbial interaction network.
• Keystone taxa (Verrucomicrobiota, SJA-15, Kineosphaera) were identified as crucial in methanol, glycerol, and acetate systems.

Conclusions:

• Carbon source profoundly influences microbial community structure, metabolic profiles, and overall denitrification performance.
• Complex microbial interactions and metabolite production are closely linked to bioreactor efficiency.
• Targeting specific microbial taxa and understanding their interactions can optimize denitrification processes.