Deinococcus frigens
Deionococcus frigens is a Gram-positive, non-motile, coccoid bacterium found in Antarctic soil. It forms orange to pink colonies and is unusually tough, tolerating cold, drought, and UV radiation. The species was discovered in 2004 by Peter Hirsch in the McMurdo Dry Valleys, isolated from the top 0–4 cm of soil after enrichment on PYGV medium at 9 °C and pH 8.0.
D. frigens is a psychrophile, growing best from 1 to 21 °C, and can tolerate up to 10% salt. It thrives in a pH range of 3.8 to 8.7 and can grow aerobically or as a facultative anaerobe. Unlike some related species, it has no flagella. The bacterium’s genome is about 2.02 million base pairs with a GC content of 65.5% and contains around 4,057 genes, of which about 3,987 encode proteins.
Its metabolism supports glycolysis, the TCA cycle, gluconeogenesis, and the pentose phosphate pathway, with enzymes for fructose and galactose processing and the ability to use glucose, acetate, and casein as carbon sources. It can transport and reduce nitrate and nitrite and reduce sulfite, and its electron transport chain includes five complexes: NADH dehydrogenase, succinate dehydrogenase, cytochrome bc1, cytochrome c oxidase, and ATP synthase.
D. frigens is related to other Deinococcus species, sharing high similarity with D. saxicola and D. marmoris, and is part of a group renowned for extreme stress resistance. This makes it a useful model for studying cold adaptation, radiation resistance, and potential applications in cancer, aging research, and space microbiology.
This page was last edited on 3 February 2026, at 07:42 (CET).