Bioaugmentation as a strategy for tailor-made volatile fatty acid production

Area of Science:

• Environmental Microbiology
• Biotechnology
• Wastewater Treatment

Background:

• Volatile fatty acids (VFAs) are key metabolites in anaerobic digestion.
• Tailoring VFA composition is crucial for various biotechnological applications.
• Cheese wastewater presents a complex substrate for VFA production.

Purpose of the Study:

• To develop a novel strategy for tailor-made volatile fatty acid (VFA) composition.
• To investigate the effect of bioaugmentation with Propionibacterium acidipropionici on VFA production.
• To analyze the microbial community shifts and correlations with VFA profiles.

Main Methods:

• Utilizing anaerobic sequencing batch reactors (ASBRs) for VFA production.
• Employing bioaugmentation with Propionibacterium acidipropionici.
• Operating reactors with cheese wastewater under alkaline pH conditions.
• Analyzing VFA concentrations and microbial community structure (gene copy number, relative abundance).

Main Results:

• Propionic acid production increased nearly fourfold in bioaugmented reactors compared to controls.
• No significant difference in overall VFA composition was observed.
• The gene copy number of P. acidipropionici increased 20-fold post-bioaugmentation.
• P. acidipropionici abundance correlated positively with total VFA and isovaleric acid.
• Relative abundance of Flavobacteriaceae increased, suggesting a syntrophic relationship.

Conclusions:

• Bioaugmentation with P. acidipropionici is an effective strategy to enhance propionic acid production from cheese wastewater.
• Shorter reactor cycles (6h) can maintain high efficiency.
• The findings provide insights into microbial interactions for targeted VFA synthesis.