Here's a further study, and nice piece on the subject.

quarium Nitrification Revisited: Thaumarchaeota Are the Dominant Ammonia Oxidizers in Freshwater Aquarium Biofilters

  • Laura A. Sauder,

  • Katja Engel,

  • Jennifer C. Stearns,

  • Andre P. Masella,

  • Richard Pawliszyn,

  • Josh D. Neufeld mail


  • Published: August 16, 2011
  • DOI: 10.1371/journal.pone.0023281




http://www.plosone.org/article/info%...l.pone.0023281