Scientists from the Chinese Academy of Sciences (CAS) have identified a strain of bacteria that can break down harmful pollutants in salty environments, such as estuaries and marine systems. The bacteria, named Dehalogenimonas strain W, has been found to effectively degrade 1,2-dichloroethane, a common industrial solvent, in conditions with high salt concentrations (Figure 1). This finding, published in Environmental Science & Technology, sheds light on how this bacterial strain adapts to extreme conditions and holds promise for bioremediation technologies.

Estuaries provide essential resources such as food and energy but have become reservoirs for hazardous substances like halogenated organic compounds (HOCs). These pollutants pose significant risks to marine biodiversity and human health. Organohalide-respiring bacteria (OHRB) are microorganisms that can use HOCs as a food source. While these bacteria are known to play a crucial role in cleaning up polluted environments, few have been found to thrive in salty conditions.

The research team at the CAS' Institute of Applied Ecology developed an enrichment culture from sediments at the Bohai Sea estuary, discovering that strain W could not only survive but also thrive in highly saline conditions (5.1% NaCl), breaking down the toxic 1,2-dichloroethane into harmless ethylene.

The study revealed that strain W has developed a unique adaptation mechanism to tolerate high salt concentrations. The bacteria produce a substance called ectoine, which helps regulate osmotic pressure, enabling survival in saline environments. Additionally, the researchers identified a unique enzyme, DdeA, in the bacteria that is responsible for breaking down the harmful chemicals.

“This discovery highlights the untapped potential of microorganisms like Dehalogenimonas to detoxify polluted estuaries and marine ecosystems,” said lead author WANG Hongyan. The findings open doors for the development of innovative biotechnological approaches to mitigate the impacts of HOCs in saline waters.

The study underscores the ecological significance of microbial communities in estuaries, offering hope for restoring these vital ecosystems through nature-based solutions.