Engineered bacterial biofloc formation enhancing phenol removal and cell tolerance.

Area of Science:

• Biotechnology
• Environmental Microbiology
• Synthetic Biology

Background:

• Microbial flocs offer resistance to toxic chemicals and harsh environments.
• Phenol is a significant environmental pollutant and a lignin-derived inhibitor.

Purpose of the Study:

• To genetically engineer Escherichia coli for enhanced biofloc formation.
• To improve microbial tolerance and removal of toxic compounds, specifically phenol.

Main Methods:

• Engineered Escherichia coli using diguanylate cyclases (DGCs) to promote biofloc formation.
• Assessed phenol removal rates and tolerance in engineered bioflocs compared to planktonic cells.
• Evaluated tolerance to other toxic compounds (furfural, HMF, guaiacol) and applicability to Pseudomonas putida.

Main Results:

• Engineered biofloc-forming E. coli showed a 2.2-fold increase in phenol removal rate.
• Bioflocs exhibited up to 149% improved tolerance to phenol and 20% enhanced phenol hydroxylase activity.
• Enhanced tolerance to furfural, 5-hydroxymethylfurfural, and guaiacol was observed.
• The biofloc strategy was successfully applied to Pseudomonas putida, increasing its phenol tolerance.

Conclusions:

• Engineered bioflocs significantly enhance microbial tolerance and removal of toxic phenolic compounds.
• This strategy is broadly applicable to different microbial species and toxic substances.
• The developed method offers a promising approach for bioproduction and bioremediation.