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South Florida Company Uses Genetic Testing To Help Keep Poop Out Of The Water

Kate Stein
Source Molecular CEO Mauricio Larenas shows off a freezer of samples.

In Florida, poop in the water is... a problem we all live with.

Bacteria from feces closes down beaches and is washed into waterways by king tide flooding. Runoff from septic tanks contributes to outbreaks of blue-green algae in state waterways, often with serious repercussions. In the summer of 2016, algal blooms on Florida's coasts choked tourism and fishing businesses; recent studies have shown the algae can cause liver damage and produce neurotoxins.

State and local leaders, among them Senate President Joe Negron, are at work on plans to address water challenges, including those linked to fecal contamination. But it can be difficult to identify the source of contamination: Is it agricultural runoff? Leaking septic tanks? Pet waste left behind by irresponsible owners?

A Miami-based company, Source Molecular, is developing genetic testing to help communities identify the causes of fecal bacteria in their water.

CEO Mauricio Larenas spoke with WLRN's Kate Stein.

Larenas with one of the robots that test water samples.

LARENAS: We're looking for a specific gene in water samples that is associated with fecal waste from humans or from wildlife, like gulls on the beach, or from pet waste. People are often not picking up their pet waste and that can introduce bacteria into the environment. And so our core focus has been on creating solutions to do environmental forensic work, which helps people identify the causes of pollution. This could be an environmental bacteria pollution which is harmful to people when they swim in the water. It can be problems that we're experiencing in Lake Okeechobee based on nutrient runoff that causes algal blooms and it could also be issues with antibiotic-resistant genes like MRSA being introduced into the environment.

WLRN: So the old technology. It was like, yes or no, there's pollution?

It didn't say at all what the pollution was.

Think of crime, right? And imagine if your police force could only see the crime was being committed. They couldn't give you a sense of whether it was a misdemeanor or if it was a real criminal offense. You probably want to know the difference. If all you knew was that crime was happening in a city and you didn't know what level of crime or what degree of crime was happening, that would probably be a concern to people. And that's what's happening right now with our beach monitoring. What the current technology tells you is that you have a certain level of pollution at the site. That's it.

How could your technology help as far as addressing specific problems, maybe say with sewers versus septic tanks versus other sources?

Martin County reached out to us recently; they went out and evaluated the upgrade of septic systems across their entire watershed. It was going to cost hundreds of millions of dollars to fix the entire network of septic tanks. They only had a fraction of the money available to them and they needed to figure out how they were going to prioritize their infrastructure management. What they did is they use this genetic technology to prioritize where they were going to be most effective in fixing that infrastructure. And this technology allowed them to target the sites where the human waste is actually coming from.

Can you give me a cost estimate of the technology that's out there currently versus the technology that you're hoping to provide?

Credit Kate Stein
A Source Molecular researcher demonstrates a procedure the company has automated as part of its testing process.

We've estimated it's a few hundred thousand dollars of manpower to build a lab. You need to have Ph.D-level researchers on staff and you need to have, in some cases, hundreds of thousands of dollars of hardware to be able to do genetic testing for environmental applications. What we're doing is we're getting it down to a very low cost. We're hoping to achieve under $40,000 for the hardware and we're hoping to get it so that a person off the street with one month of training will be able to do genetic testing.

How are you going to accomplish that? 

As an example, our current test method is 11 pages long to do the genetic analysis. One of our scientists, a recent Berkeley bioengineering graduate, is turning that 11-page template into a five-option Web site. You choose five things and the robot will do everything for you.

Credit Kate Stein
Kate Stein
Source Molecular is developing a program so its genetic testing can be executed by someone with only a month or two of training.

This interview has been edited for clarity.

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