12
Dinoflagellates and Toxin
Production
Joana Assunção
1
and F. Xavier Malcata
1,2
Introduction
Marine life possesses huge structural and chemical diversity, which may support development of
promising new drugs with higher efficacy than its terrestrial counterparts (Malve 2016; Joseph 2016).
Therefore, the interest for novel bioactive compounds from marine sources has boomed in recent years,
namely with regard to treatment of a few human diseases. More than 25,000 structurally diverse bioactive
products have indeed been isolated from marine species since 1965 (Blunt et al. 2016). Dinoflagellates
(a type of microalgae) are an important group which has already contributed to this number, and is likely
to contribute even further in terms of pharmacological roles (Gallardo-Rodríguez et al. 2012a). This
complex taxon is estimated to include over 2300 living species (Gomez 2012)—of which more than 50
have been found to produce marine toxins (Gallardo-Rodríguez et al. 2012a; Daranas et al. 2001). Besides
their intrinsic ecological role in aquatic environments, dinoflagellates have adapted to a broad variety
of environments—thus reflecting their extraordinary flexibility; fossil records thereof date back several
hundred million years (Taylor 1987; Wisecaver and Hackett 2011; Gomez 2012). Occasional and sudden
proliferation of dinoflagellates in marine environments has led to a phenomenon called Harmful Algal
Blooms (HABs); they are likely to produce toxins that can negatively distress marine life, especially via
poisoning fish and shellfish (Hallegraeff 2003). Moreover, HABs and associated toxin production can
impact human health if direct consumption of contaminated shellfish (or fish) takes place afterwards; and
disturb economic activities, with unfavorable implications upon fisheries or tourism (Anderson 1995;
Smayda 1997).
Despite associated risks, the aforementioned toxins possess remarkable biotechnological features—
thus justifying an effort to still seek more toxin biocompounds, and eventually produce them at large scale.
Unfortunately, only a meager quantity of those molecules has reached the market—and still with several
limitations. The restricted availability thereof from natural sources (Haefner 2003), and the limited and
unfeasible routes for chemical synthesis, or the scarce advances in genetic engineering of dinoflagellates
1
LEPABE – Laboratory of Process Engineering, Environment, Biotechnology and Energy, College of Engineering,
University of Porto, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
2
Department of Chemical Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
* Corresponding author: fmalcata@fe.up.pt
Dinoflagellates and Toxin
Production
Joana Assunção
1
and F. Xavier Malcata
1,2
Introduction
Marine life possesses huge structural and chemical diversity, which may support development of
promising new drugs with higher efficacy than its terrestrial counterparts (Malve 2016; Joseph 2016).
Therefore, the interest for novel bioactive compounds from marine sources has boomed in recent years,
namely with regard to treatment of a few human diseases. More than 25,000 structurally diverse bioactive
products have indeed been isolated from marine species since 1965 (Blunt et al. 2016). Dinoflagellates
(a type of microalgae) are an important group which has already contributed to this number, and is likely
to contribute even further in terms of pharmacological roles (Gallardo-Rodríguez et al. 2012a). This
complex taxon is estimated to include over 2300 living species (Gomez 2012)—of which more than 50
have been found to produce marine toxins (Gallardo-Rodríguez et al. 2012a; Daranas et al. 2001). Besides
their intrinsic ecological role in aquatic environments, dinoflagellates have adapted to a broad variety
of environments—thus reflecting their extraordinary flexibility; fossil records thereof date back several
hundred million years (Taylor 1987; Wisecaver and Hackett 2011; Gomez 2012). Occasional and sudden
proliferation of dinoflagellates in marine environments has led to a phenomenon called Harmful Algal
Blooms (HABs); they are likely to produce toxins that can negatively distress marine life, especially via
poisoning fish and shellfish (Hallegraeff 2003). Moreover, HABs and associated toxin production can
impact human health if direct consumption of contaminated shellfish (or fish) takes place afterwards; and
disturb economic activities, with unfavorable implications upon fisheries or tourism (Anderson 1995;
Smayda 1997).
Despite associated risks, the aforementioned toxins possess remarkable biotechnological features—
thus justifying an effort to still seek more toxin biocompounds, and eventually produce them at large scale.
Unfortunately, only a meager quantity of those molecules has reached the market—and still with several
limitations. The restricted availability thereof from natural sources (Haefner 2003), and the limited and
unfeasible routes for chemical synthesis, or the scarce advances in genetic engineering of dinoflagellates
1
LEPABE – Laboratory of Process Engineering, Environment, Biotechnology and Energy, College of Engineering,
University of Porto, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
2
Department of Chemical Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
* Corresponding author: fmalcata@fe.up.pt