Home • Botryococcus braunii Showa
Micrograph of Botryococcus braunii.
Micrograph of Botryococcus braunii. Photo credit: Timothy Devarenne, Texas A&M University.

The genome sequence and gene models of Botryococcus braunii Showa strain v2.1 were downloaded from Phytozome, the Joint Genome Institute (JGI) Plant genomics portal on June 11, 2018. In order to ensure this genome is comparable to those sequenced by the JGI, we applied filters to remove if present: 1) transposable elements, 2) pseudogenes, 3) alternative transcripts and overlapping models, 4) alleles on secondary scaffolds and 5) unsupported short models. This resulted in the removal of 9,742 models and the generation of the FilteredModels1 (GeneCatalog) gene track. All published models are available in the ExternalModels track. Please note that this copy of the genome is not maintained by NCBI and is therefore not automatically updated. In order to allow comparative analyses with other algal genomes sequenced by the JGI, a copy of this genome is incorporated into PhycoCosm. The JGI Annotation Pipeline was used to add functional annotation to this genome. The latest data is available at Phytozome.

Botryococcus braunii Race B (Showa strain) is a colonial fresh water green microalga that is well known for producing large amounts of liquid hydrocarbons that can be readily converted into petroleum-equivalent transportation fuels such as gasoline, jet fuel, and diesel using existing petroleum hydrocracking procedures. The hydrocarbons from the B race of B. braunii are known as botryococcenes and generally accumulate to a level of 30-50% of algal dry weight. The cells of a B. braunii colony are held together by an extracellular matrix made up of cross-linked long chain hydrocarbon aldehydes surrounded by a polysaccharide sheath. The majority of the colony hydrocarbons are stored in the spaces around the cross-linked hydrocarbon network and provide the colony with several advantages including floatation and tolerance to desiccation.

The Showa strain of B. braunii, race B, is also known as the Berkeley strain since it was originally isolated from Berkeley, CA, but strains of all three B. braunii races, A, B, and L, can be found throughout Earth from tropical to alpine climates. The genome size of the Showa strain of B. braunii has been estimated at 166.2 Mb and the genome was sequenced in order to better understand the underlying molecular mechanisms for hydrocarbon biosynthesis.

Genome Reference(s)