Functional characterization of an efficient ibuprofen-mineralizing bacterial consortium

Area of Science:

• Environmental microbiology
• Bioremediation of pharmaceuticals

Background:

• Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (IBU) are frequently detected in the environment.
• Limited knowledge exists regarding the functional characteristics of highly efficient IBU-mineralizing microbial consortia.
• IBU's environmental persistence and potential ecological risks necessitate effective degradation strategies.

Purpose of the Study:

• To functionally characterize an enhanced ibuprofen-mineralizing microbial consortium (C6) developed through continuous enrichment.
• To identify key microbial players responsible for ibuprofen degradation in different enrichment stages.
• To isolate and characterize specific ibuprofen-degrading bacterial strains.

Main Methods:

• Continuous enrichment of an initial microbial consortium (C1) to obtain an ibuprofen-mineralizing consortium (C6).
• 16S rRNA gene sequencing to analyze bacterial community structure and shifts during enrichment.
• Isolation and identification of key ibuprofen-degrading bacterial strains (Streptomyces sp. D218 and Pseudomonas sp. M20).

Main Results:

• Continuous enrichment significantly altered the bacterial community composition, enriching for Methylobacter, Pseudomonas, and Dokdonella spp. in consortium C6.
• The relative abundance of Streptomyces sp. decreased significantly in consortium C6 compared to consortium C1.
• Streptomyces sp. D218 (from C1) and Pseudomonas sp. M20 (from C6) were isolated as key ibuprofen degraders, indicating a shift in dominant functional players.
• The study demonstrated that enrichment changed the core functional strains, impacting the ibuprofen degradation process.

Conclusions:

• Continuous enrichment is effective in modifying microbial community structure for enhanced ibuprofen degradation.
• Key bacterial players, such as Pseudomonas, become dominant in enriched consortia for efficient ibuprofen biotransformation.
• The identified bacterial strains and insights into community dynamics offer valuable resources for the bioremediation of NSAIDs in the environment.