Low-temperature phenol-degrading microbial agent: construction and mechanism

Area of Science:

• Environmental Microbiology
• Bioremediation
• Wastewater Treatment

Background:

• Phenol is a common industrial pollutant that requires effective degradation methods.
• Low-temperature environments pose challenges for microbial phenol degradation.
• Developing efficient microbial consortia is crucial for bioremediation.

Purpose of the Study:

• To isolate and characterize cold-tolerant phenol-degrading bacteria.
• To optimize a microbial agent for low-temperature phenol biodegradation.
• To evaluate the degradation kinetics and efficiency of the constructed microbial agent.

Main Methods:

• Isolation and identification of three bacterial strains: Pseudomonas veronii Ju-A1, Leifsonia naganoensis Ju-A4, and Rhodococcus qingshengii Ju-A6.
• Optimization of microbial agent composition using Response Surface Methodology (RSM).
• Analysis of phenol degradation kinetics under varying concentrations (first-order and modified Gompertz models).

Main Results:

• Isolated strains efficiently degrade phenol at 12°C via ortho-cleavage of catechol, producing cis, cis-muconic acid.
• Optimized microbial agent completely degraded 200 mg/L phenol within 36 hours.
• Degradation followed first-order kinetics below 160 mg/L and the modified Gompertz model above 200 mg/L.

Conclusions:

• A novel microbial agent composed of three cold-tolerant bacteria effectively degrades phenol at low temperatures.
• This approach offers a feasible and advantageous strategy for the bio-enhanced treatment of phenol-contaminated wastewater.
• The study demonstrates significant potential for industrial application in low-temperature bioremediation.