Radio X-Philes: Bacteria

Ionizing-radiation-resistant organisms (IRROs) are organisms for whom more than 1,000 Gy (100,000 rd or CGS) are needed

Here organisms are listed first by the upper end of their radiation range, then by OGGy, then by the lower end of their radiation range, and for any organisms for which these properties are unknown, they will be listed in alphabetical order at the end.

Bacteria

Phylum: Actinobacteria

Class: Rubrobacteria

Order: Rubrobacterales

Family: Rubrobacteraceae

Genus: Rubrobacter

Phylum: Deinococcus-Thermus

Class: Deinococci

Order: Deinococcales

Family: Deinococcaceae

Genus: Deinococcus

Other entry

Here radiophilic and radioresistant bacteria are listed alphabetically.

Bacteria marked with an asterisk (*) are endospore-forming polyextremotolerant organisms. Bacterial endospores tend to give the bacteria capable of producing them polyextremotolerance. Endospores are known for being able to survive extremely high doses of radiation, vacuum dessication, extreme heat and cold, lack of nutrients, and in some cases even the passage of hundreds of millions of years (for example, Virgibacillus marismortui (formerly Bacillus marismortui and Bacillus strain 2-9-3) was revived by scientists from 250-million-year-old spores (Vreeland, 2000); for comparison, the first dinosaurs began appearing about 220 MYA — 30 million years later). Although these endospore-forming bacteria can survive a variety of harsh conditions, endospore-formation is not done for reproduction, as with fungal spore formation, but is instead a last-ditch effort to survive conditions the bacterium would not otherwise be able to, which means these critters aren’t true polyextremophiles, because they don’t (necessarily) actually grow better in extreme conditions, and in their endospore form don’t even grow at all.

Many bacteria of the phylum Firmicutes (to which the endospore-forming bacteria belong) are also facultatively radiotrophic in an indirect way: capable of consuming H₂ produced from radioactive decay.

References