Botryococcus
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| Botryococcus Temporal range: Precambrian - Recent > | |
|---|---|
 | |
| Botryococcus braunii | |
Scientific classification  | |
| Clade: | Viridiplantae |
| Division: | Chlorophyta |
| Class: | Trebouxiophyceae |
| Order: | Trebouxiales |
| Family: | Botryococcaceae |
| Genus: | Botryococcus Kützing, 1849 |
| Type species | |
| Botryococcus braunii Kützing | |
| Species[1] | |
|
See text | |
Botryococcus is a genus of green algae. It is a microscopic or semi-microscopic alga that is found in freshwater habitats worldwide. It consists of colonies of cells in an irregular, gelatinous matrix.[1]
Botryococcus produces high amounts of oil, which often make the colonies colored yellowish to reddish. When seen with a microscope, colonies release oil under the pressure of a cover slip.[2] Because of its high amounts of oil, Botryococcus is of interest to the field of biotechnology, as it is a promising source of biofuel.[3]
In addition to its current biosynthetic capabilities, fossils of the genus are known since Precambrian times, and form the single largest biological contributor to crude oil, and are a major component of oil shales.[4]
The genus and its holotype were described in 1849 by Friedrich Traugott Kützing.[5]
Description
Botryococcus consists of irregularly shaped colonies of cells; in some species or when old, the colonies may be composed of subcolonies connected by gelatinous strands. Cells are 6-20 μm long and 2.5-8 μ wide, elongate, obovoid and narrower near the center of the colonies, ovoid, or spherical, and arranged around the periphery of the colony in one layer. They are partially or wholly submerged in a gelatinous matrix, or may be attached to the gelatinous matrix at the base. The matrix is often impregnated with oil that gives the colony a yellowish, brownish or reddish color. Cells are uninucleate (with one nucleus) and contain a single parietal, cup-shaped chloroplast with one pyrenoid (but the pyrenoid may not be visible due to oil droplets crowding the protoplast).[1]
Reproduction in Botryococcus occurs asexually by the formation of autospores. The protoplast divides into two, four, eight or 16 autospores, while the parent cell walls gelatinize. Sexual reproduction and zoospores have not been reported in this genus.[1]