Beggiatoa

A genus of proteobacteria, Beggiatoa are filamentous. They are amongst the largest prokaryotes, with cells about 200 micrometres in diameter. They can act as an indicator species since they are present and flourish in marine environments which have been subject to pollution, where the bacteria become visible as a whitish layer.

Members of this genus are chemosynthesisers, meaning that they utilize inorganic substances for the energy to make carbohydrates.

Beggiatoa gigantea

The bacterium Beggiatoa gigantea obtains the energy required to survive by reducing compounds of sulphur; this characteristic means it is classified in the leucothiobacteria.

Hydrogen sulphide is the compound typically reduced, however its deficiency results in the use of elemental sulphur (reduced to sulphuric acid) or of thiosulphate. There is an average of about 735kJ released per reaction.