Successful implementation within TKI Watertechnologie
New DNA method to detect blue-green algae
Every summer, in the Netherlands and elsewhere in Europe, bathing in outdoor locations is forbidden or advised against because of the overgrowth of cyanobacteria, that is, blue-green algae. KWR works with Intertek, within the framework of TKI Water Technology, on widening the application of DNA techniques for the detection of four dominant cyanobacteria strains. In addition, KWR develops a new method to detect the fifth, and remaining, blue-green algae strain.
“The ‘last’ blue-green algae can now also be detected using DNA techniques”
In the Netherlands, bathing locations are assessed on the basis of the Blue-Green Algae Protocol (2012). Edwin Kardinaal, researcher and team leader at KWR, explains: “Under suspicious circumstances, samples are collected to be microscopically analysed. It’s a labour-intensive and specialised method. That’s why, for the last few years, we have been developing quantitative PCR (qPCR) methods for the four most common strains. The qPCR methods should make it easier to quickly identify and quantify the species.” In 2013, in order to make these methods more widely applicable, KWR and Intertek – the company that has been commissioned by Dutch Directorate for Public Works and Water Management (Rijkswaterstaat) to monitor bathing water – carry out the TKI Genomics project.
Implementation of existing techniques
Fons van der Linden is Business Development Consultant at Intertek, and is involved in this capacity in the project. “In 2013 we have successfully implemented the qPCR method in our operations. Together with KWR, we selected the equipment and established the protocols. We then analysed more than 300 samples both microscopically and using qPCR methods. The microscopic counts and the qPCR results, in 95% of the cases, produced an equal risk assessment.” What does this mean for the company? “It means that we’ll continue applying DNA techniques in monitoring blue-green algae in bathing water. The method is reliable and fast, and will save money over time.”
Developing new method
The Blue-Green Algae Protocol includes another blue-green algae strain which Dutch water managers should be alert to: Woronichinia. This strain occurs primarily in urban waters and can present a health risk for dogs, among others. Within the same project, the researchers develop a new qPCR method to enable the detection of cells from this strain as well. “This was not simple,” says researcher Bart Wullings. “This blue-green algae is difficult to grow in a laboratory, and practically nothing was known about its DNA.” Wullings and his colleagues collect water samples from several urban water bodies, select about 90 Woronichinia colonies, and analyse the DNA of a specific gene. They then were in a position to develop a reliable qPCR method for Woronichinia as well. “This means that all blue-green algae species, as named in the Blue-Green Algae Protocol, can now be detected using DNA techniques,” says Kardinaal. “That’s a result we can be proud of.”
© 2018 KWR Watercycle Research Institute
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Manager Microbial Water Quality and Health and scientific researcher