Shewanellales

Shewanellales is an order of Gammaproteobacteria, a class within the bacterial phylum Proteobacteria. Members of this order are typically Gram-negative rods and are found in a wide range of environments, including marine waters, sediments, soil, and even clinical settings. A key characteristic of many Shewanellales is their ability to respire using insoluble electron acceptors, such as metal oxides. This metabolic versatility allows them to play significant roles in biogeochemical cycles, particularly in the reduction of iron and manganese.

The order currently contains a single family, Shewanellaceae, and a single genus, Shewanella. The genus Shewanella is well-known for its diverse metabolic capabilities, including the breakdown of various organic compounds and the production of enzymes like proteases and lipases. Some species of Shewanella have also been investigated for their potential in bioremediation due to their ability to degrade pollutants.

While many Shewanellales are saprophytic or involved in elemental cycling, some species, particularly within the genus Shewanella, can be opportunistic pathogens in humans and fish, although infections are generally rare and often associated with compromised immune systems or specific exposure routes. Research into Shewanellales continues to uncover novel metabolic pathways and ecological functions, highlighting their importance in microbial ecology and biotechnology.