Laura Moro
Biosensor Srl, Italy
Title: A novel optical bioassay for the detection of pesticides in marine environment exploiting an array of green photosynthetic microalgae
Biography
Biography: Laura Moro
Abstract
Increasing pollution of marine environment requires development of sensitive, cheap and adaptable early warning systems for on-site monitoring of chemical contaminants. Herein, we present an optical bioassay exploiting an array of green photosynthetic microalgae as a promising alternative for monitoring seawater pollutants, which can provide rapid and quantitative toxicity information while assessing the harmful effect on marine ecosystems. For bioassay optimization, several microalgae species from Chlorophycea, Trebouxiophycea, dinoflagellates, diatoms and Eustigmatophycea groups with different marine and non-marine origins were studied in marine environmental conditions. The lipid content of selected species was analyzed, since lipids have been proposed to be involved in protection mechanisms against salt stress. The fluorescence response of the algae photosystem II was examined in real-time in the presence of three commonly found marine pollutants that act as photosynthesis inhibitors: simazine, diuron and irgarol. Algae from marine origin were discarded because of their low fluorescence response. The chemical pollutants were tested alone or in combination in a seawater matrix with non-marine algae species, and results validated by LC-MS. Pesticides were detected in seawater samples in the ng/L- low µg/L range, and a synergistic effect was observed when analyzing pesticide mixtures. The different algae species showed slightly diverse sensitivities for the three pollutants, being Chlorella mirabilis the most sensitive with a limit of detection of 67 ng/L for diuron. Therefore, a green microalgae-based bioassay was successfully developed for real-time monitoring of marine water quality and evaluation of bio-toxicity by the fluorescence analysis of photosystem II