Toxin-producing Anabaena flos-aquae induces settling of Chlamydomonas reinhardtii, a competing motile alga

Kearns, Katherine; Hunter, Mark D.

doi:10.1007/s002480000086

Cited by 101 publications

(46 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Singh et al [51] showed that purified Microcystin-LR (MC-LR) extracted from Microcystis aeruginosa had a negative effect on the growth of several green algae and cyanobacteria. Kearns and Hunter [52] also showed that MC and anatoxin-a both inhibit the motility of the green alga Chlamydomonas reinhardtii . The cyanobacterium Synechococcus elongatus was also shown to be inhibited by the presence of the Microcystin-RR (MC-RR), possibly due to inhibition of photosynthesis by the toxin [53].…”

Section: Exploring the Evidencementioning

confidence: 99%

Interpreting the Possible Ecological Role(s) of Cyanotoxins: Compounds for Competitive Advantage and/or Physiological Aide?

2013

View full text Add to dashboard Cite

To date, most research on freshwater cyanotoxin(s) has focused on understanding the dynamics of toxin production and decomposition, as well as evaluating the environmental conditions that trigger toxin production, all with the objective of informing management strategies and options for risk reduction. Comparatively few research studies have considered how this information can be used to understand the broader ecological role of cyanotoxin(s), and the possible applications of this knowledge to the management of toxic blooms. This paper explores the ecological, toxicological, and genetic evidence for cyanotoxin production in natural environments. The possible evolutionary advantages of toxin production are grouped into two main themes: That of “competitive advantage” or “physiological aide”. The first grouping illustrates how compounds produced by cyanobacteria may have originated from the need for a cellular defence mechanism, in response to grazing pressure and/or resource competition. The second grouping considers the contribution that secondary metabolites make to improved cellular physiology, through benefits to homeostasis, photosynthetic efficiencies, and accelerated growth rates. The discussion also includes other factors in the debate about possible evolutionary roles for toxins, such as different modes of exposures and effects on non-target (i.e., non-competitive) species. The paper demonstrates that complex and multiple factors are at play in driving evolutionary processes in aquatic environments. This information may provide a fresh perspective on managing toxic blooms, including the need to use a “systems approach” to understand how physico-chemical conditions, as well biological stressors, interact to trigger toxin production.

show abstract

Section: Exploring the Evidencementioning

confidence: 99%

Interpreting the Possible Ecological Role(s) of Cyanotoxins: Compounds for Competitive Advantage and/or Physiological Aide?

2013

View full text Add to dashboard Cite

show abstract

“…Domoic acid, which is a structural analog of kainic acid and proline, is produced by diatoms, and causes neuronal depolarization [59]. In some cases, heterotrophic bacteria can degrade toxins produced by phytoplankton [60] Another example is the cyanobacterium algae that produce the anatoxin-a (bicyclic secondary amine) and the microcystin-LR (cyclic heptapeptide) toxins that paralyze the motile green alga Chlamydomonas , leading to fast sedimentation of Chlamydomonas [45,61] (Figure 3). The metabolites belonging to the indole class of alkaloids have anti-algal activity, and consequently are associated with allelopathic interactions.…”

Section: Introductionmentioning

confidence: 99%

“…Besides this, high concentrations of C. reinhardtii extracellular products completely inhibited microcystin accumulation. These results demonstrate that cyanobacterial toxin production may be regulated by a complex mechanism involving growth phase dependence and environmental conditions [61] (Another compound is Portoamide which is a cyclic peptide produced by Chlorella vulgaris . Thus metabolites differentially inhibited some cyanobacteria, including Cylindrospermopsis raciborskii.…”

Section: Introductionmentioning

confidence: 99%

Allelopathy as a potential strategy to improve microalgae cultivation

Mendes

Vermelho

2013

Biotechnol Biofuels

116

View full text Add to dashboard Cite

One of the main obstacles for continuous productivity in microalgae cultivation is the presence of biological contaminants capable of eliminating large numbers of cells in a matter of days or even hours. However, a number of strategies are being used to combat and prevent contamination in microalgae cultivation. These strategies include the use of extreme conditions in the culture media such as high salinity and high pH to create an unfavorable environment for the competitive organisms or predators of the microalgae. Numerous studies have explored the potential of naturally occurring bioactive secondary metabolites, which are natural products from plants and microorganisms, as a source of such compounds. Some of these compounds are herbicides, and marine and freshwater microalgae are a source of these compounds. Microalgae produce a remarkable diversity of biologically active metabolites. Results based on the allelopathic potential of algae have only been described for laboratory-scale production and not for algae cultivation on a pilot scale. The adoption of allelopathy on microalgal strains is an unexplored field and may be a novel solution to improve algae production. Here we present information showing the diversity of allelochemicals from microalgae and the use of an allelopathic approach to control microalgae cultivation on a pilot scale based on R&D activities being carried out in Brazil for biodiesel production.

show abstract

“…MC-LR is one of the most commonly occurring [2, 4] and the most toxic microcystin [5]. The intact cells as well as the toxins released after cellular lysis can be responsible for the toxic effects observed in many organisms, from microalgae [6] to mammals [7] including human [8–10]. …”

Section: Introductionmentioning

confidence: 99%

Acute Exposure to Microcystin-Producing CyanobacteriumMicrocystis aeruginosaAlters Adult Zebrafish (Danio rerio) Swimming Performance Parameters

Kist

Piato

Rosa

et al. 2011

Journal of Toxicology

View full text Add to dashboard Cite

Microcystins (MCs) are toxins produced by cyanobacteria (blue-green algae), primarily Microcystis aeruginosa, forming water blooms worldwide. When an organism is exposed to environmental perturbations, alterations in normal behavioral patterns occur. Behavioral repertoire represents the consequence of a diversity of physiological and biochemical alterations. In this study, we assessed behavioral patterns and whole-body cortisol levels of adult zebrafish (Danio rerio) exposed to cell culture of the microcystin-producing cyanobacterium M. aeruginosa (MC-LR, strain RST9501). MC-LR exposure (100 μg/L) decreased by 63% the distance traveled and increased threefold the immobility time when compared to the control group. Interestingly, no significant alterations in the number of line crossings were found at the same MC-LR concentration and time of exposure. When animals were exposed to 50 and 100 μg/L, MC-LR promoted a significant increase (around 93%) in the time spent in the bottom portion of the tank, suggesting an anxiogenic effect. The results also showed that none of the MC-LR concentrations tested promoted significant alterations in absolute turn angle, path efficiency, social behavior, or whole-body cortisol level. These findings indicate that behavior is susceptible to MC-LR exposure and provide evidence for a better understanding of the ecological consequences of toxic algal blooms.

show abstract

Toxin-producing Anabaena flos-aquae induces settling of Chlamydomonas reinhardtii, a competing motile alga

Cited by 101 publications

References 32 publications

Interpreting the Possible Ecological Role(s) of Cyanotoxins: Compounds for Competitive Advantage and/or Physiological Aide?

Interpreting the Possible Ecological Role(s) of Cyanotoxins: Compounds for Competitive Advantage and/or Physiological Aide?

Allelopathy as a potential strategy to improve microalgae cultivation

Acute Exposure to Microcystin-Producing CyanobacteriumMicrocystis aeruginosaAlters Adult Zebrafish (Danio rerio) Swimming Performance Parameters

Contact Info

Product

Resources

About