“Biotechnology” and “water purification” aren’t usually themes that you hear mentioned in the same sentence. There are plenty of biotech startups aiming to use cutting-edge molecular approaches like RNA interference (RNAi) to develop profitable new drugs—but fewer people, if any, talk about how these technologies might help people in developing countries where safe drinking water is in short supply. Indeed, at first blush, the idea that molecules as fragile as snippets of RNA could be used on an industrial scale to kill pathogens in water seems farfetched.
But that’s exactly what a Somerville, MA-based startup called 349Q hopes to do. In stealth mode until last week, the company has now begun talking to reporters about its plans, which call for identifying genes common to the main species of dangerous microbes found in water, then engineering viruses that could manufacture RNA strands capable of shutting down the microbes’ basic metabolic processes. The company’s technology, for which it has obtained provisional patents, grows out of work in the laboratory of Claudia Gunsch, a microbial engineering expert in the Civil and Environmental Engineering department at Duke University in Durham, NC. Mark Modzelewski, a cleantech and venture capital veteran based in Somerville (and an Xconomy guest essayist), is handling the company’s fundraising and business development.
With supplies of fresh, clean water chronically limited around the world, water purification is obviously an area crying out for new technological solutions. In a Technology Review interview published last week, prominent Silicon Valley venture capitalist Steve Jurvetson called water purification “a trillion-dollar opportunity” and said the water industry exhibits “probably the biggest mismatch between a screaming, enormous market and a lack of technology innovation I’ve ever seen.”
There’s no shortage of technologies for purifying contaminated water—they include distillation, carbon filtration, membrane filtration, ultraviolet irradiation, reverse osmosis, and ion exchange. But all have their shortcomings, ranging from high cost and high energy consumption to low flow rates.
Modzelewski says he has spent years on the lookout for a new water purification technology that merits a venture capital investment. Over breakfast last week, he laid out his criteria for such a technology: “It needed to cost the same as anything we have now; it needed to be very easy to attach to current water-treatment systems, without requiring any expensive retrofitting; and it had to be completely different.”
The idea that RNA interference might provide a solution is new, radical, and largely untested. A lot of the drama in pharmaceutical research on RNA interference is around how to shepherd RNA molecules past all the blood-borne enzymes that would normally chew them up and deliver them safely into cells, where they can then disrupt the activity of targeted genes. Delivering the molecules inside the body has been such a preoccupation for researchers, according to Duke’s Gunsch, that there wasn’t any data on whether they could be disseminated to microbes through water.
That’s the experiment Gunsch and Sara Morey, a PhD candidate in her lab, first tried last year. They filled a sample of water with a strain of fungus that had been engineered to produce a particular yellow protein. They then added RNA snippets that had been custom-sequenced to silence the gene responsible for the protein’s production. The water’s color changed instantly—indicating that
