Mulberry green alga
Botryococcus braunii
Botryococcus braunii is a globally distributed planktonic green alga that forms characteristic mulberry-shaped colonies. These colonies consist of individual cells embedded within a tough matrix of biopolymers and liquid hydrocarbons. The alga is scientifically significant because it can store up to 75% of its dry biomass as oil, making it a prime candidate for biofuel production research. It primarily inhabits standing freshwater and brackish environments with low to moderate nutrient levels, playing a vital role as a primary producer.
Details
Oxygen production
Actively produces oxygen through photosynthesis within the euphotic zone.
Habitat function
Serves as a microhabitat and food source for various microorganisms.
Nutrient uptake
Efficient uptake of dissolved nitrogen and phosphate from the water.
Food source for
Filter-feeding zooplankton and some specialized micro-herbivores.
Human use
Intensively researched for biofuel production (algal oil) and as a source of hydrocarbons.
Ecology
Ecological role
Primary producer in the pelagic food web; fixation of atmospheric CO2 and production of lipids.
Natural predators
Zooplankton, especially filter-feeding rotifers and small crustaceans.
Competitor species
Other phytoplankton species like Scenedesmus or Microcystis under higher nutrient concentrations.
Ecosystem service
Oxygen production and carbon sequestration; potential raw material source for sustainable energy.
Threats
Severe eutrophication of water bodies and chemical pollution.
Scientific profile
Profile
Distinguishing features
Extreme liquid hydrocarbon content (up to 75% of dry weight); characteristic grape-like structure; color shift from green to bright orange/red in stationary phase; high buoyancy due to lipids.
Reproduction
Asexual via colony fragmentation (splitting of the mother colony into daughter colonies) or by formation of autospores within individual cells.
Protection & threats
Status not on standard scale
Main threats
Eutrophication of water bodies (displacement by more competitive cyanobacteria), chemical stress from agricultural herbicides.
Conservation measures
Protection and restoration of nutrient-poor waters; reduction of diffuse nutrient inputs from the catchment area; maintenance of natural hydromorphology.