The invention relates to a phytase derived from Citrobacter braakii and related phytases. The phytases belong to the acid histidine phosphatase family, are acid-stable, of an excellent performance in animal feed, of a high specificity towards the substrate phytate, and expectedly of a high specific activity. The invention also relates to the corresponding DNA, the recombinant and wild-type production of the phytases, as well as the use thereof.