ASSESSMENT OF CYANOBACTERIAL TOXINOGENIC GENOTYPES AND ESTIMATION OF TOXIN CONTENT IN URBAN LAKES

摘要

The increase of the human population and the consequent intensification of anthropogenic activities, such as agriculture and industry, in association with an inefficient treatment of wastewaters, have contributed to an increase of toxic cyanobacterial blooms. Cyanobacterial hepatotox-ins, such as microcystins (MC) and nodularins, have been responsible for the poisoning of animals and humans who ingest or come into contact with toxic blooms. The lakes in city park of Porto are eutrophic almost since its construction. This work studied the occurrence of toxic cyano-bacteria and cyanotoxins in urban lakes by using microscopy, PCR (polymerase chain reaction), real-time PCR (qPCR), and ELISA (enzyme linked immuno-sorbent assay). The presence of toxic cyanobacteria and their toxins was detected throughout the sampling period, from July 2008 until February 2009. The highest amount of MC reached 10.2 μg MC-LR equivalents/L in November. Despite the urban man-made lakes in the city park of Porto are not used as a source of drinking water and recreation, contact with cyanobacterial toxins may occur. The concentration of MC found in the different lakes suggests the need to establish monitoring programs in urban lakes to avoid risks to humans and environmental health. Different techniques should be used in order to optimize the approach.