New testing method can stop toxic algae blooms in their tracks
Too much guesswork about the toxicity of algae blooms in Australian waterways has led to unneeded preemptive restrictions. But a new technology can now verify the presence of harmful cyanobacteria in water and predetermine if toxins are likely to be produced.
Over the past few years, Diagnostic Technology has validated a molecular-based test, Phytoxigene CyanoDTec, to sniff out toxin-producing cyanobacteria, which threatens the health of humans and animals in water environments.
Toxins can be produced by many strains of cyanobacteria, but as toxicity is not uniform among strains, classification methods are unable to accurately predict toxicity.
Diagnostic Technology Managing Director Mark Van Asten said the current methods of determining the toxicity of algae blooms have been inadequate because of the focus on species identification.
“The current system is based on cell counting and identification. Australian water regulations require toxin testing only when the enumeration of potentially toxic producers reach a certain level, but this can be ambiguous and time consuming,” he said.
“Traditionally, all you can confirm is that a species that has been known to cause toxicity is present, but by using our technology you can confirm very quickly the risks of a toxin being present and which toxin to test for.”
Van Asten said a more reliable assessment of potential toxicity is achieved by examining the genetic footprint. “The critical thing about our technology is that it brings identification screening or risk assessment into the genetic era. Our technology relies on identifying the cell characteristics and DNA – we look for the genetic footprint that relates to a cell’s ability to produce the toxin,” he said.
“In a number of studies it has been shown that there is a good correlation between the number of genes and the amount of toxin present.
“Additionally, we can pick up these genes sooner than someone can pick up the toxin. In practice, laboratories have been able to identify a harmful algae event a week or two before the toxin is detected.”
The new technology is being utilised in a number of US states, and in Australia there are a number of customers, including Tweed Shire Council and Sydney Water.
Tweed Shire Council Lab Coordinator Paul Wright said the technology has been hugely beneficial and, while he wouldn’t suggest removing toxicity assessment completely, it has helped take the guesswork out of testing.
“It offers more reliability. The other benefit is that you are doing different assays for different potentially toxic species all at once,” he said.
“When you send your samples off to labs it can take quite a while to get a result back. But now we can run our testing within two or three hours. It’s very responsive.
“We’ve had blooms that are potentially toxic, but we have been able to show that the blooms are not toxic, which gives us a lot of relief. And that’s only possible using genetic testing.”