Abstract Detail

Recent Topics Posters

Bates, Scott T. [3], Cropsey, Garrett W.G. [1], Caporaso, Gregory [2], Knight, Rob [1], Fierer, Noah [3].

Bacterial communities of lichens: structure and potential functions .

Lichens are commonly described as a mutualistic symbiosis between fungi and “algae” (Chlorophyta or Cyanobacteria); however, they are also known to possess internal (endolichenic) bacterial communities. Recent DNA-based research suggests that endolichenic microbes are an integral component of lichens and that the classical view of this symbiotic relationship should be expanded to include bacteria. These studies, however, used techniques that do not provide much detail about the phylogenetic structure of these communities. Here we used bar-coded pyrosequencing to survey bacteria within four different lichen species across rock outcrops in a localized area of the western United States. Bacterial sequences obtained from the lichen samples suggest that these communities are dominated by taxa in the Alphaproteobacteria and Acidobacteria, and that endolichenic community structure is best predicted by the species of lichen. Across our samples, we also recovered numerous phylotypes that were closely related to sequences isolated from lichens in prior studies, as well as those that appear to represent novel bacterial lineages. Most interestingly, bacteria from a previously described lichen-associated bacterial lineage (LAR1; putative nitrogen fixing Rhizobiales) were among the more dominant phylotypes in all four of our lichen species; moreover, many sequences from our samples were also closely related to other known diazotrophs (e.g., Azospirillum, Bradyrhizobium, and Frankia). Our findings confirm the presence of highly structured bacterial communities within lichens species, and provide additional evidence for the functional roles that bacteria may play within lichen symbioses.

Broader Impacts:

1 - University of Colorado, Department of Ecology and Evolutionary Biology, Boulder, CO, 80309, USA
2 - University of Colorado, Department of Chemistry and Biochemistry, Boulder, CO, 80309, USA
3 - University of Colorado, Cooperative Institute for Research in Environmental Sciences, Boulder, CO, 80309, USA

Keywords:
endolichenic bacteria
lichens
pyrosequencing
Symbiosis.

Presentation Type: Recent Topics Poster
Session: P
Location: Hall A/Convention Center
Date: Monday, August 2nd, 2010
Time: 5:30 PM
Number: PRT004
Abstract ID:1103