Efficient hexabromocyclododecane-biodegrading microorganisms isolated in Taiwan.

Area of Science:

• Environmental Science
• Microbiology
• Bioremediation

Background:

• Hexabromocyclododecane (HBCD) poses environmental risks due to its toxicity, persistence, and bioaccumulation.
• Effective remediation strategies are crucial for mitigating HBCD pollution.

Purpose of the Study:

• To identify and characterize microorganisms capable of degrading HBCD.
• To investigate the efficiency and optimal conditions for HBCD degradation by isolated bacteria.
• To elucidate the HBCD removal mechanism and explore enhancement methods.

Main Methods:

• Isolation and identification of HBCD-degrading bacteria from Taiwan soil.
• Assessing degradation efficiency under varying conditions (pH, temperature, HBCD concentration).
• Investigating the role of surfactants and oxygen-releasing compounds in HBCD removal.

Main Results:

• Bacillus cereus and Bacillus subtilis were identified as HBCD degraders.
• Bacillus cereus exhibited rapid HBCD degradation with a half-life of 0.911 days.
• Optimal degradation by B. cereus occurred at pH 7.0, 35°C, and 0.10 ppm HBCD.
• Debromination was identified as the primary removal mechanism for HBCD by B. cereus.
• Tween 60 enhanced HBCD removal, while CaO2 did not.

Conclusions:

• Bacillus cereus demonstrates significant potential for the bioremediation of HBCD-contaminated environments.
• Understanding the degradation pathway and optimizing conditions can enhance the effectiveness of microbial HBCD removal.