Seasonal Dynamics of Microcystis spp. and Their Toxigenicity as Assessed by qPCR in a Temperate Reservoir

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Antonio Martins (Author) Other; Cristiana Moreira (Author) Other; Micaela Vale (Author) Other; Marisa Freitas (Author) Other; Ana Regueiras (Author) Other; Agostinho Antunes (Author) FCUP; Vitor Vasconcelos (Author) FCUP

Journal

Title: Marine Drugs

Vol. 9 No. 10

Pages: 1715-1730

ISSN: 1660-3397

Publisher: MDPI

Indexing

ISI Web of Knowledge - 20 Citations

Scopus - 27 Citations

Scientific classification

FOS: Medical and Health sciences > Basic medicine

Other information

Authenticus ID: P-002-KP2

DOI: 10.3390/md9101715

Abstract (EN): Blooms of toxic cyanobacteria are becoming increasingly frequent, mainly due to water quality degradation. This work applied qPCR as a tool for early warning of microcystin(MC)-producer cyanobacteria and risk assessment of water supplies. Specific marker genes for cyanobacteria, Microcystis and MC-producing Microcystis, were quantified to determine the genotypic composition of the natural Microcystis population. Correlations between limnological parameters, pH, water temperature, dissolved oxygen and conductivity and MC concentrations as well as Microcystis abundance were assessed. A negative significant correlation was observed between toxic (with mcy genes) to non-toxic (without mcy genes) genotypes ratio and the overall Microcystis density. The highest proportions of toxic Microcystis genotypes were found 4-6 weeks before and 8-10 weeks after the peak of the bloom, with the lowest being observed at its peak. These results suggest positive selection of non-toxic genotypes under favorable environmental growth conditions. Significant positive correlations could be found between quantity of toxic genotypes and MC concentration, suggesting that the method applied can be useful to predict potential MC toxicity risk. No significant correlation was found between the limnological parameters measured and MC concentrations or toxic genotypes proportions indicating that other abiotic and biotic factors should be governing MC production and toxic genotypes dynamics. The qPCR method here applied is useful to rapidly estimate the potential toxicity of environmental samples and so, it may contribute to the more efficient management of water use in eutrophic systems.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 16