Aphanizomenon flos-aquae

Species of bacterium

Aphanizomenon flos aquae is a brackish and freshwater species of cyanobacteria of the genus Aphanizomenon found around the world, including the Baltic Sea and the Great Lakes. Cyanobacteria were the first organisms to achieve photosynthesis. Chlorophyll and phycocyanine—two pigments contained in cyanobacteria—allow the vegetative cells to absorb light and transform it into nutrients. The individual vegetative cells that form Aphanizomenon flos aquae are cylindrical and elongated. Each individual cell is composed of hyaline. When attached to a trichome, heterocysts import carbohydrates which may act as a reducing agent and an energy source for nitrogen fixation. It has been shown that heterocysts contain a nitrogenase complex which allows them to take part in nitrogen fixation. Other requirements for nitrogen fixation include ATP, low potential electrons, and an anaerobic environment. These blooms occur in areas of high nutrient loading, historical or current. During bloom formation, Aphanizomenon flos aquae photosynthetically produces biomass. These accumulated mats of biomass are able to grow due to the concentration of nutrients available in eutrophic ecosystems accompanied with high reproductive rates and water temperatures. At high concentrations, these blooms can be ecologically harmful to the aquatic species that cohabitate with the cyanobacteria. In addition to their odiferous presence, cyanobacterial blooms have been associated with lowered dissolved oxygen content, increased turbidity, and the accelerated release of nutrients from sediments. Most sources worldwide are toxic, containing both hepatic and neuroendotoxins. Most cyanobacteria (including Aphanizomenon) produce BMAA, a neurotoxin amino acid implicated in ALS/Parkinsonism. Toxicity of A. flos aquae has been reported in Canada, Germany and China. Aphanizomenon flos aquae is known to produce endotoxins, the toxic chemicals released when cells die. Once released (lysed), and ingested, these toxins can damage liver and nerve tissues in mammals. In areas where water quality is not closely monitored, the World Health Organization has assessed toxic algae as a health risk, citing the production of anatoxin a, saxitoxins, and cylindrospermopsin. Dogs have been reported to have become ill or have fatal reactions after swimming in rivers and lakes containing toxic A. flos aquae. Microcystin toxin has been found in all 16 samples of A. flos aquae products sold as food supplements in Germany and Switzerland, originating from Lake Klamath: 10 of 16 samples exceeded the safety value of 1 μg microcystin per gram. University professor Daniel Dietrich warned parents not to let children consume A. flos aquae products, since children are even more vulnerable to toxic effects, due to lower body weight, and the continuous intake might lead to accumulation of toxins. Dietrich also warned against quackery schemes selling these cyanobacteria as medicine against illnesses such as attention deficit hyperactivity disorder, causing people to omit their regular drugs.

The Klamath have been ingesting A. flos aquae for centuries. Containing significant amounts of phenylethylamine. This endogenous molecule is often considered a general neuromodulator, making it effective at combating depression and anxiety. Klamin is an extract of A. flos aquae that concentrates phenylethylamine which can act as MAO B inhibitors. Additionally, in a Canadian study studying the effect of A. flos aquae on the immune and endocrine systems, as well as on general blood physiology, found that consuming A. flos aquae had a profound effect on natural killer cells (NKCs). A. flos aquae triggers the movement of 40% of the circulating NKCs from the blood to tissues. Once in the tissues, the NKCs main function is immune surveillance to eliminate cancerous or other infected cells.