Acidithiobacillales

Acidithiobacillales is an order of proteobacteria, specifically within the class Gammaproteobacteria. This order is comprised of acidophilic, obligately chemolithoautotrophic bacteria that are capable of oxidizing reduced inorganic sulfur compounds to derive energy.

Taxonomy

The Acidithiobacillales order includes two families: Acidithiobacillaceae and Ectothiorhodospiraceae. The Acidithiobacillaceae family includes the genera Acidithiobacillus and Thermithiobacillus, while the Ectothiorhodospiraceae family includes the genera Ectothiorhodospira, Halorhodospira, and Thioalkalivibrio.

Characteristics

Members of the Acidithiobacillales order are known for their ability to survive in extremely acidic environments, often with a pH of 2 or lower. They are also capable of oxidizing inorganic sulfur compounds, such as elemental sulfur, thiosulfate, and tetrathionate, to derive energy for growth. This unique metabolic capability allows them to thrive in environments such as acid mine drainage and sulfur springs.

Ecological Role

Acidithiobacillales play a significant role in the global sulfur cycle, contributing to the oxidation of reduced sulfur compounds in various environments. They are also involved in the bioleaching of sulfide minerals, a process that is exploited in the mining industry for the extraction of certain metals.

Medical Relevance

While Acidithiobacillales are not typically associated with human disease, their ability to survive in extreme environments and their unique metabolic capabilities make them of interest in the field of microbiology.