Cyanobacteria are photosynthetic bacteria that share some properties with algae and are found naturally in lakes, streams, ponds, and other surface waters. Cyanobacteria can multiply rapidly in surface waters and cause “blooms.” Several types of cyanobacteria, for example Anabaena sp, have gas-filled cavities that allow them to float at the surface or at different levels below the surface, depending on light conditions and nutrient levels. This can cause cyanobacteria to concentrate on the surface of the water, resulting in a pea soup green color or a blue-green “foam.” Some cyanobacteria such as Planktothrix sp can be found in bottom sediments and float to the surface when mobilized by storm events or other sediment disturbances. Other cyanobacterial blooms may remain dispersed in the water column (Cylindrospermopsis sp.) leading to general discoloration of the water. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Although several techniques have been developed to control cyanobacterial blooms and remove cyanobacterial cells or metabolites in water treatment processes, the effect of these treatments on the membrane integrity of cyanobacterial cells has not been studied and compared systematically. Cyanobacterial blooms can be harmful to the environment, animals and human health. Bloom decay consumes oxygen, creating hypoxic conditions that cause plant and animal death. Under favorable conditions of light and nutrients, some species of cyanobacteria produce toxic secondary metabolites, known as cyanotoxins. The most common toxin-producing cyanobacteria are Microcystis, Anabaena, Planktothrix, Anabaenopsis, Aphanizomenon (producing microcystin – LR), Cylindrospermopsis, Aphanizomenon, Anabaena, Lyngbya, Rhaphidiopsis, Umezakia (producing Cylindrospermopsin), Anabaena, Planktothrix, Aphanizomenon, Cylindrospermopsis, Oscillatoria (producing anatoxins). The conditions that cause cyanobacteria to produce cyanotoxins are not well understood. Some species with the ability to produce toxins may not produce them under all conditions. These species are often members of common flower-forming genera. There are both non-toxic and toxic varieties of most common toxin-producing cyanobacteria, and it is impossible to tell whether a species is toxic or non-toxic by looking at it. Furthermore, even when toxin-producing cyanobacteria are present, they may not actually produce toxins. Additionally, some species of cyanobacteria can produce multiple types and variations of cyanotoxins. Molecular tests are available to determine whether cyanobacteria. Please note: this is just a sample. Get a custom paper from our expert writers now. Get a custom essay. Microcystis, for example, carries the toxin gene; Quantitative cyanotoxin analysis is needed to determine whether cyanobacteria are actually producing the toxin. Water contaminated with cyanobacteria can occur without associated taste and odor problems. In most cases, cyanobacterial toxins exist naturally intracellularly (in the cytoplasm) and are retained within the cell. Anatoxin-a and microcystin variants are found intracellularly approximately 95% of the time during the flowering growth phase. For these species, when the cell dies or the cell membrane breaks down, toxins are released into the water (extracellular toxins). However, in other species, for example Cylindrospermopsin, a significant amount of toxin.