Self-Assembled Living Microreactors for Selective Microcystin Removal via Cascade Sieving, Adsorption and...

Area of Science:

• Environmental Science
• Materials Science
• Biotechnology

Background:

• Harmful cyanobacterial blooms produce microcystins, posing a significant threat to global water safety.
• Current water treatment methods struggle with efficient and selective removal of these potent toxins.

Purpose of the Study:

• To develop a self-assembled living microreactor for integrated microcystin removal.
• To investigate the system's efficiency, stability, and scalability in degrading microcystins.

Main Methods:

• Encapsulating microcystin-degrading bacteria within a biochar-reinforced double-network hydrogel.
• Evaluating the microreactor's performance under various environmental conditions (pH, ions, organic matter).
• Assessing mechanical stability, cell leakage, bioactivity, and reusability through repeated cycles and continuous biofiltration.

Main Results:

• The microreactor demonstrated size- and charge-selective removal of microcystins, outperforming other organic matter removal.
• High degradation efficiency was maintained under harsh conditions (pH 5-9, 10-200 mg/L inorganic ions, 5-20 mg/L natural organic matter).
• The system showed excellent mechanical stability, negligible cell leakage, and achieved nearly complete microcystin-LR removal over five cycles and in environmental water.

Conclusions:

• The living microreactor offers a robust and scalable platform for selective microcystin biodegradation and water remediation.
• The integrated approach of molecular sieving, adsorption, and enzymatic degradation provides a novel strategy for complex aqueous systems.
• This work presents a generalizable design for programmable living materials with potential applications in environmental cleanup.