Prymnesium parvum
Encyclopedia
Prymnesium parvum is a haptophyte
, belonging to Haptophyta (=Prymnesiophyta). The species is of concern because of its ability to produce a toxin. It is a flagellated alga that is normally found suspended in the water column. It was first identified in North America
in 1985 and it is not known if it was introduced artificially (e.g., an invasive species or missed in previous surveys). Toxin production mainly kills fish and appears to have little effect on cattle or humans. This distinguishes it from red tide
, which are algal bloom whose toxins lead to harmful effects in people. Although no harmful effects are known, it is recommended not to consume dead or dying fish exposed to a P. parvum bloom.
range of 0.1%–10% with an optimum at 0.3%–6% although strains collected in different places appear to have different salinity tolerances. The alga produces dimethylsulfoniopropionate
(DMSP) and other unknown polyol
s, likely as an adaptation to osmoregulation
. The environment must be between 2 °C (35.6 °F) and 30 °C (86 °F) for P. parvum to live. Growth at a pH
of as low as 5.8 has been observed, but cells typically prefer higher pH ranges. The organism prefers highly light environments, but growth can be inhibited by excessive light (photoinhibition
). The organism is capable of heterotrophic growth in the dark in the presence of glycerol
and grazes on bacteria, especially when phosphate is limited. It has therefore been hypothesized that P. parvum satisfies its phosphate needs by consuming bacteria. P. parvum can use a wide range of nitrogen
sources, including ammonium
, nitrate
, amino acid
s (which ones apparently depends of pH), creatine
, but is unable to use urea
.
New evidence has shown that the toxins produced by this alga are induced by physiological stresses, such as nitrogen and phosphorus depletion due to competition with the environment.
Haptophyte
The haptophytes, classified either as the Prymnesiophyta or Haptophyta, are a division of algae.The term "Haptophyceae" is sometimes used. This ending implies classification at a lower level...
, belonging to Haptophyta (=Prymnesiophyta). The species is of concern because of its ability to produce a toxin. It is a flagellated alga that is normally found suspended in the water column. It was first identified in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
in 1985 and it is not known if it was introduced artificially (e.g., an invasive species or missed in previous surveys). Toxin production mainly kills fish and appears to have little effect on cattle or humans. This distinguishes it from red tide
Red tide
Red tide is a common name for a phenomenon also known as an algal bloom , an event in which estuarine, marine, or fresh water algae accumulate rapidly in the water column and results in discoloration of the surface water. It is usually found in coastal areas...
, which are algal bloom whose toxins lead to harmful effects in people. Although no harmful effects are known, it is recommended not to consume dead or dying fish exposed to a P. parvum bloom.
Biology
P. parvum grows grows in a salinitySalinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
range of 0.1%–10% with an optimum at 0.3%–6% although strains collected in different places appear to have different salinity tolerances. The alga produces dimethylsulfoniopropionate
Dimethylsulfoniopropionate
Dimethylsulfoniopropionate , is an organosulfur compound with the formula 2S+CH2CH2COO−. This zwitterionic metabolite found in marine phytoplankton, seaweeds, and some species of terrestrial and aquatic vascular plants...
(DMSP) and other unknown polyol
Polyol
A polyol is an alcohol containing multiple hydroxyl groups. In two technological disciplines the term "polyol" has a special meaning: food science and polymer chemistry.- Polyols in food science :...
s, likely as an adaptation to osmoregulation
Osmoregulation
Osmoregulation is the active regulation of the osmotic pressure of an organism's fluids to maintain the homeostasis of the organism's water content; that is it keeps the organism's fluids from becoming too diluted or too concentrated. Osmotic pressure is a measure of the tendency of water to move...
. The environment must be between 2 °C (35.6 °F) and 30 °C (86 °F) for P. parvum to live. Growth at a pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
of as low as 5.8 has been observed, but cells typically prefer higher pH ranges. The organism prefers highly light environments, but growth can be inhibited by excessive light (photoinhibition
Photoinhibition
Photoinhibition is light-induced reduction in the photosynthetic capacity of a plant, alga, or cyanobacterium. Photosystem II is more sensitive to light than the rest of the photosynthetic machinery, and most researchers define the term as light-induced damage to PSII...
). The organism is capable of heterotrophic growth in the dark in the presence of glycerol
Glycerol
Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...
and grazes on bacteria, especially when phosphate is limited. It has therefore been hypothesized that P. parvum satisfies its phosphate needs by consuming bacteria. P. parvum can use a wide range of nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
sources, including ammonium
Ammonium
The ammonium cation is a positively charged polyatomic cation with the chemical formula NH. It is formed by the protonation of ammonia...
, nitrate
Nitrate
The nitrate ion is a polyatomic ion with the molecular formula NO and a molecular mass of 62.0049 g/mol. It is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically-bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a...
, amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
s (which ones apparently depends of pH), creatine
Creatine
Creatine is a nitrogenous organic acid that occurs naturally in vertebrates and helps to supply energy to all cells in the body, primarily muscle. This is achieved by increasing the formation of Adenosine triphosphate...
, but is unable to use urea
Urea
Urea or carbamide is an organic compound with the chemical formula CO2. The molecule has two —NH2 groups joined by a carbonyl functional group....
.
New evidence has shown that the toxins produced by this alga are induced by physiological stresses, such as nitrogen and phosphorus depletion due to competition with the environment.
External links
- Removal of Prymnesium parvum (Haptophyceae) cells under different nutrient conditions by clay
- Literature review of the microalga Prymnesium parvum and its associated toxicity
- Influence of different nutrient conditions on cell density, chemical composition and toxicity of Prymnesium parvum (Haptophyta) in semi-continuous cultures