State Water Resources Research Institute Program

Project ID: 2008SC58B
Title: Improved Early Detection Methods for Microcystin-Producing Cyanobacteria
Project Type: Research
Start Date: 3/01/2008
End Date: 2/28/2009
Congressional District: Third
Focus Categories: Methods, Toxic Substances, Water Quality
Keywords: Algal toxins, blue-green algae, cyanobacteria, cyanotoxins, decision analysis, enzyme-linked immunosorbent assay, ELISA, harmful algal blooms, microcystin, molecular genetics, monitoring, polymerase chain reaction, PCR, reverse-transcriptase ploymerase chain reaction, RT-PCR, risk assessment
Principal Investigators: Johnson, Alan R. ; Yang, Yanru
Federal Funds: $ 33,814
Non-Federal Matching Funds: $ 68,342
Abstract: The presence of cyanotoxins (toxins produced by cyanobacteria, also known as blue-green algae) in surface waters used for drinking water sources and recreation is receiving increasing attention around the world as a public health concern. Microcystins are a group of cyclic heptapeptides produced by various cyanobacteria, which upon ingestion exert marked toxic effects on the mammalian liver. Microcystins are the most commonly encountered class of cyanotoxin in drinking water, and have frequently been associated with acute poisoning of animals and occasionally humans, and pose a risk for chronic liver toxicity in humans. Microcystins impose considerable economic costs when the use of surface waters for drinking or recreation is impaired by the presence of microcystin-producing cyanobacteria. There is currently no Federal water standard for microcystins, but the World Health Organization has put forth a provisional "guideline value" of 1 µg/L (or 1 ppb) for microcystin-LR (the most common variant) in drinking water. The US Environmental Protection Agency has placed microcystin on the Contaminant Candidate List in consideration of developing a drinking water standard.

Environmental managers can select from a wide array of types of measurements to design a monitoring protocol for cyanobacteria and associated toxins. Each monitoring procedure has associated benefits and costs, and each type of measurement carries some potential for false positive or false negatives. Selection of an appropriate monitoring protocol requires a quantitative assessment of the value of information and the risks associated with delay to obtain more detailed information versus the risks associated with possible management or remediation actions. Increasing attention has been directed toward tiered monitoring protocols that seek to maximize benefits and minimize the costs. There is a need to develop a decision support framework that would allow a systematic assessment of the trade-offs involved in any particular monitoring and management strategy.

This project will focus on the development of molecular genetic methods for detecting genes or transcripts associated with the synthesis of microcystins. The use of these molecular genetic assays for early detection of microcystin-producing organisims in natural waters will be compared with the widely used ELISA assay for microcystin. Molecular genetic methods are expected to be much more sensitive (lower detection limits) than the ELISA assay, an so may afford an improved method for early warning of a risk due to microcystin-producing cyanobacteria. We will use the data from our studies, as well as information gleaned from the scientific literature, to develop a decision support framework to evaluate alternative monitoring protocols employing a mix of traditional and molecular genetic methods to detect microcystin-producing cyanobacteria in water.

Progress/Completion Report, PDF

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