Scientists from the Institute of Applied Ecology of the Chinese Academy of Sciences have identified a strain of bacteria that can break down harmful pollutants in saline environments, such as estuaries and marine systems. The bacteria, named Dehalogenimonas strain W, were found to be effective in degrading 1,2-dichloroethane, a common industrial solvent, under conditions of high salinity. 

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 such as 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 saline conditions.

In this study, the researchers developed an enrichment culture from sediments in the Bohai Sea estuary and discovered 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.

They found 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, allowing them to survive in saline environments. 

In addition, 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 such as Dehalogenimonas to detoxify polluted estuaries and marine ecosystems," said WANG Hongyan, lead author of the study. 

The results open doors for the development of innovative biotechnological approaches to mitigate the impact of HOCs in saline waters.

The study highlights the ecological importance of microbial communities in estuaries and offers hope for restoring these vital ecosystems through nature-based solutions.