Nanofilters Mimic Bacterial Mechanism to Clean Contaminated Water

Scientists have developed solar-powered nanofilters that remove antibiotics from water in lakes and rivers twice as efficiently as the best existing technology, by using the same devious mechanism that enables some bacteria to shrug off powerful antibiotics.

David Wendell and Vikram Kapoor explain in a report that appeared in ACS' journal Nano Letters that antibiotics from toilets and other sources find their way into lakes and rivers, with traces appearing in 80 percent of waterways. This is not good since those antibiotics foster emergence of new antibiotic-resistant bacteria, while harming beneficial microbes in ways that can degrade aquatic environments and food chains. While filters containing activated carbon can remove antibiotics from effluent at municipal sewage treatment plants, before its release into waterways, but they are far from perfect. Thats why the scientists said they decided to look for a better technology.

They succeeded by inverting the mechanism that enables bacteria to survive doses of antibiotics, and describe the development and successful laboratory testing of capsule-like "vesicles" employing this method. This system pumps antibiotics out of bacterial cells before any damage can occur. Wendell and Kapoor turned it around, so that the system pumps antibiotics into the vesicles. That way, they can be collected and recycled or shipped for disposal. In addition to the pump, the vesicles contain a propulsion system driven by sunlight. The pump system could be adapted to clean hormones, heavy metals and other undesirable materials from water, the scientists state.

Paper:

"Engineering Bacterial Efflux Pumps for Solar-Powered Bioremediation of Surface Waters" NanoLetters