Assessing Ecotoxicity in Marine Environment Using Luminescent Microalgae: Where Are We At?

Abstract

Nowadays, microalgae are particularly used to assess the environmental impact of contaminants in aquatic systems. Naturally present in some algal species, bioluminescence is highly used in application fields related to environmental monitoring. Bioluminescent dinoflagellates have played a pivotal role in this domain. When exposed to heavy metals or toxic organic compounds, bioluminescent dinoflagellates have the capacity to decrease light emission. In addition, new molecular tools allow the possibility to produce genetically modified microorganisms which are able to perform luminescence. Combined with the luciferase reporter gene, two main genetic constructions can be employed. Activation of a specific inducible promoter induces the luminescence gene transcription and this signal increases over time. Constitutive promoters result in a high basal expression level of the reporter gene. During exposure to a potential toxic pollutant, the basal expression level will decrease due to the toxic effect. Toxicity bioassays based on engineered luminescent Chlorophyta microalgae are among the most sensitive tests and are an invaluable complement to classical toxicity assays.

Luminescent Microbial Bioassays and Microalgal Biosensors as Tools for Environmental Toxicity Evaluation

“…QwikLite QwikLite™ (Fernández-Piñas et al 2014;Lapota et al 2007;Rosen et al 2008;Sanchez-Ferandin 2015) Pyrophacus steinii…”

“…Procedure based on bioluminescence in the dinoflagellates Pyrocystis lunula was developed into ASTM method E1924-97 ("Standard guide for conducting toxicity tests with bioluminescent dinoflagellates"), but it was withdrawn in 2013. The application of bioluminescent dinoflagellate bioassays in environmental applications is quite extensive as they have been used to assess the toxicity of heavy metals, several pesticides, and complex matrices such as industrial wastewater, seawater, groundwater, or marine sediments (Bao et al 2008(Bao et al , 2011Fetters et al 2016;Heimann et al 2002;Hildenbrand et al 2015;Okamoto et al 1999;Rosen et al 2008;Sanchez-Ferandin 2015;Stauber et al 2008).…”

“…The marine green alga Ostreococcus tauri isolated from a Mediterranean coastal lagoon was modified by Sanchez-Ferandin (2015). Four strains were constructed: the translational bioreporter TOC1-Luc (chlorophyll a binding protein expression (CAB)), the transcriptional bioreporter pCAB::luc (promoter of chlorophyll a binding protein expression), and the translational bioreporters cyclin A-Luc and CDKA-Luc (cyclin A and cyclin dependent kinase, respectively).…”

Luminescent Microbial Bioassays and Microalgal Biosensors as Tools for Environmental Toxicity Evaluation

“…QwikLite TM (Fernández-Piñas et al 2014;Lapota et al 2007;Okamoto et al 1999;Rosen et al 2008;Sanchez-Ferandin 2015).…”

“…The most used dinoflagellate species in bioluminescence test are Ceratocorys horrida, Lingulodinium polyedrum (formerly Gonyaulax polyedra), Pyrocystis fusiformis, Pyrocystis lunula, Pyrocystis noctiluca and Pyrophacus steinii. Lapota et al (1993) developed a toxicity bioassay based on these organisms to evaluate toxic effects of different substances (Lapota et al 1994) have been used to assess the toxicity of heavy metals, several pesticides and complex matrices such as industrial wastewater, seawater, groundwater or marine sediments (Bao et al 2008;Bao et al 2011;Fetters et al 2016;Heimann et al 2002;Hildenbrand et al 2015;Okamoto et al 1999;Rosen et al 2008;Sanchez-Ferandin 2015;Stauber et al 2008).…”