What kind of toxins do cyanobacteria secrete?

What kind of toxins do cyanobacteria secrete?

Cyanobacterial toxins – cyanotoxins The cyanotoxins are a diverse group of compounds, both from the chemical and the toxicological points of view. In terms of their toxicological target, cyanobacterial toxins are hepatotoxins, neurotoxins, cytotoxins, dermatotoxins and irritant toxins (Wiegand & Pflugmacher, 2005).

Is microcystin a neurotoxin?

Microcystin-LR (MC-LR) and Cylindrospermopsin (CYN) are produced by cyanobacteria. Although being considered as a hepatotoxin and a cytotoxin, respectively, different studies have revealed neurotoxic properties for both of them.

Is Anabaena toxic?

Anabaena may produce a few different toxins, including anatoxin and microcystin. Ingestion of small amounts of toxin can cause gastrointestinal distress. If elevated levels of the algal toxin anatoxin are present in the water and ingested, serious neurological damage can result.

Do cyanobacteria give off toxins?

Overview of Cyanobacteria Some freshwater cyanobacterial blooms or cyanoHABs are able to produce highly potent toxins, known as cyanotoxins.

Why do cyanobacteria produce toxins?

Effects of cyanobacterial harmful algal blooms The bloom decay consumes oxygen, creating hypoxic conditions which result in plant and animal die-off. Under favorable conditions of light and nutrients, some species of cyanobacteria produce toxic secondary metabolites, known as cyanotoxins.

What toxic gas did cyanobacteria produce?

Some cyanobacteria form harmful algal blooms causing the disruption of aquatic ecosystem services and intoxication of wildlife and humans by the production of powerful toxins (cyanotoxins) such as microcystins, saxitoxin, and cylindrospermopsin.

How does microcystin affect the liver?

Liver damage and cell death can be seen microscopically as soon as 20 minutes following injection of a lethal dose of microcystin LR. Within an hour, the liver cells (hepatocytes) die, losing their connection to each other and disrupting the normal architecture of the liver [18, 19].

How does microcystin work?

As with mammals, microcystins are actively taken up by the liver in fish where they disrupt normal cellular activity by inhibiting protein phosphatases [54, 57-63]. Inhibition of these enzymes in fish can ultimately result in widespread cellular death and loss of liver structure [reviewed by 50].

What are Cyanotoxins and microcystins?

The cyanotoxins are a very diverse group of toxins from both the chemical and toxicology standpoint. Toxicities include neurotoxicity, hepatotoxicity, cytotoxicity and dermatotoxicity. The microcystins are the most common algae toxin found and are associated with Microcystis, Anabaena, Oscillatgoria, Nostoc, Hapalosiphon and Anabaenopsis species.

What are the signs and symptoms of microcystin toxicity?

Microcystin-affected individuals can have a sudden onset of gastroenteritis, hemorrhagic diarrhea, and hypovolemic shock; acute liver failure and seizures precede death. Anatoxin-a is a nicotinic receptor agonist that causes muscle fasciculations followed by neuromuscular blockade, collapse, dyspnea, cyanosis, seizures, and death.

What bacteria produce anatoxins?

The neurotoxic anatoxins (anatoxin-a and anatoxin-a s) are mainly produced by cyanobacteria in the Anabaena genus, but also by other genera, such as Planktothrix, Oscillatoria, Microcystis, Aphanizomenon, Cylindrospermum, and Phormidium.

Is Anabaena toxic to horses?

Intoxication of horses is rare, but algal toxins can cause sudden death. Microcystis, Anabaena, Planktothrix, Nostoc, Oscillatoria, and Anabaenopsis produce hepatotoxins (microcystins); most problems are associated with Microcystis spp.