Efficient caproic acid production from lignocellulosic biomass by bio-augmented mixed microorganisms

Area of Science:

• Biotechnology
• Environmental Science
• Microbiology

Background:

• Carboxylate platform production of caproic acid offers eco-friendly waste treatment.
• Current methods face challenges with low yields and selectivity.
• A specialized microbiome (DCB) shows potential for high-level caproic acid production.

Purpose of the Study:

• To enhance caproic acid yield from lignocellulosic biomass using bioaugmentation.
• To investigate the impact of Clostridium kluyveri on DCB microbiome performance.
• To optimize caproic acid production from rice straw.

Main Methods:

• Bioaugmentation of a cellulolytic acid-producing microbiome (DCB) with Clostridium kluyveri.
• Cultivation using rice straw as a lignocellulosic substrate.
• Addition of exogenous ethanol to facilitate the process.

Main Results:

• Caproic acid concentration increased 7-fold to 12.9 g/L.
• Caproic acid selectivity improved 4.5-fold to 55.1%.
• Clostridium kluyveri introduced an efficient reverse β-oxidation pathway and enriched beneficial bacteria.

Conclusions:

• Bioaugmentation with Clostridium kluyveri is an effective strategy to improve caproic acid yield and selectivity.
• This method enhances the degradation of lignocellulosic biomass and short-chain fatty acid production.
• The study presents viable bioaugmentation approaches for optimizing caproic acid production from waste biomass.