Ferrovum is a recently found new genus of acidophilic iron-oxidizing bacteria. Ferrovum spp. dominate the microbial community of a pilot plant for biological mine-water treatment and together with some Gallionella relatives appear to be key players of the process. Isolation of Ferrovum strains should greatly be facilitated by a new APPW medium. Sequencing of the genome of Ferrovum sp. JA12 so far did not point to any alternative electron donors and also did not reveal genes for nitrogen fixation.