No extremes

I am reading a very interesting general microbiology book at the moment called "Discover the World of Microbes" by Gerhard Gottschalk.

In the chapter on extremophiles it mentions two amazing microbes, Picrophilus torridus and Natronomonas pharaonis. The first is perfectly happy to grow at pH 0 and 65 degrees celsius, and the second originates from soda lakes where high salinity and a pH 11 are part of the ambient conditions. A quick fossick through their genomes indicates to me that they do not have anything approaching a nitrile hydratase about their genome, sadly. I suspect that in conditions with such extremes of low pH, nitriles aren't commonly encountered, which would remove the reason for something with a streamlined genome to retain related enzyme activities. In our OBC paper on nitrile hydratases, we did assay one from Nitriliruptor alkaphilus which came from a soda lake, and there are other genomic hints of alkaline-tolerant nitrile hydratase containing organisms. Perhaps that is the only type of extremophilic nitrile hydratase we can expect to find?