Archaeal Antimicrobials: An Undiscovered Country
Richard F. Shand and Kathryn J. Leyva
from: Archaea: New Models for Prokaryotic Biology (Edited by: Paul Blum). Caister Academic Press, U.K. (2008)
Peptide or protein antibiotics have been discovered in all three domains of life, and their production is nearly universal. Bacteriocin and eucaryocin research is well established, while research on archaeocins is still in its infancy. To date, only eight archaeocins (seven halocins and one sulfolobicin) have been partially or fully characterized, but hundreds of archaeocins are believed to exist, especially within the haloarchaea. The prevalence of archaeocins from other members of this domain is unknown simply because no one has looked for them. The discovery of new halocins hinges on recovery and cultivation of haloarchaeal organisms from the environment. For example, samples from a novel hypersaline field site, Wilson Hot Springs, recovered 350 halophilic organisms; preliminary analysis of 75 isolates showed that 48 were archaeal and 27 were bacterial. Significantly, 77% inhibited the growth of at least one other isolate. Inter-domain antagonisms were also present with 43 haloarchaeons inhibiting halophilic members of the domain Bacteria and 7 Bacteria antagonized haloarchaeons. Finally, archaeocin research provides excellent opportunities for discovery of novel antibiotics that may have clinical applications in addition to unique models for training students both in and outside the classroom read more ...