Hydrogenophilaceae

Hydrogenophilaceae
Scientific classification
Kingdom:	Bacteria
Phylum:	Proteobacteria
Class:	Betaproteobacteria
Order:	Hydrogenophilales
Family:	Hydrogenophilaceae
Genera
Hydrogenophilus Thiobacillus

The Hydrogenophilaceae are a family of Betaproteobacteria, with two genera. Like all Proteobacteria they are Gram-negative. Hydrogenophilus are thermophilic, growing around 50 °C and obtaining their energy from oxidizing hydrogen. It includes the genera Hydrogenophilus and Thiobacillus (see below for the removal of certain species).

Thiobacillus spp. can be used in pest control, such as potato scabs. If an affected area is treated with sulfur and Thiobacillus spp., the bacteria will oxidise the sulfur to sulfuric acid, which will destroy the pest, as the potato scabs cannot tolerate acidic conditions. Thiobacillus thioparus may contribute to the formation of acid rain through the oxidation of sulfur dioxide to sulfurous acid.

Hydrogenophilus thermoluteolus is a facultative chemolithoautotroph that previously had only been found in hot springs. However, it was isolated in 2004 from ice core samples retrieved from a depth of ~3 km under the ice layer covering Lake Vostok in Antarctica. The presence of this thermophilic bacteria in the ice suggests that a geothermal system exists beneath the cold water body of Lake Vostok.

Obsolete Thiobacillus species

The genus Thiobacillus, was redefined to include only those species included among the Betaproteobacteria. Other member organisms once named "Thiobacillus" were transferred to Gammaproteobacteria:

• "Thiobacillus thiooxidans" was moved to Acidithiobacillus
• "Thiobacillus neapolitanus" was moved to Halothiobacillus
• "Thiobacillus tepidarius" was moved to Thermithiobacillus