Thiotrichales

Overview

Thiotrichales bacteria in a natural environment

The Thiotrichales are an order of Gammaproteobacteria, a class within the phylum Proteobacteria. This order is known for its members that are often found in sulfur-rich environments, where they play a significant role in the sulfur cycle. The bacteria in this order are typically characterized by their ability to oxidize sulfur compounds, which is a key aspect of their metabolism.

Characteristics

Thiotrichales are generally large, filamentous bacteria. They are often found in marine environments, particularly in areas with high concentrations of hydrogen sulfide. These bacteria are capable of oxidizing hydrogen sulfide to sulfate, a process that is crucial for the detoxification of sulfide-rich environments.

Morphology

Members of the Thiotrichales order are typically filamentous and can form large mats in their natural habitats. They are often visible to the naked eye due to their size and the dense mats they form. The cells are usually rod-shaped and can vary in length.

Metabolism

Thiotrichales are chemolithoautotrophs, meaning they obtain energy by oxidizing inorganic molecules, such as hydrogen sulfide, and use carbon dioxide as a carbon source. This metabolic capability allows them to thrive in environments where organic carbon is limited but inorganic sulfur compounds are abundant.

Ecology

Close-up of Thiotrichales in a sulfur-rich environment

Thiotrichales are commonly found in marine environments, particularly in hydrothermal vents, cold seeps, and other areas where hydrogen sulfide is present. They play a crucial role in the sulfur cycle by converting toxic hydrogen sulfide into less harmful sulfate, thus supporting the ecosystem by detoxifying the environment and providing a source of sulfate for other organisms.

Genera

The order Thiotrichales includes several genera, some of which are well-studied due to their ecological importance and unique metabolic capabilities. Notable genera include:

• Beggiatoa - Known for forming white mats in sulfur-rich environments.
• Thioploca - Forms large, visible mats and is known for its ability to store nitrate.
• Thiomargarita - Includes some of the largest known bacteria, visible to the naked eye.

Related pages

• Proteobacteria
• Sulfur cycle
• Hydrothermal vent
• Chemolithoautotroph