The Amazon Basin of the Mud World: Dizzying Microbial Diversity at Guerrero Negro's Salt Mats.

Presenter: Ruth Ley, Cornell University
When: June 9, 2003 12AM PDT

Microbial mats are laminated, light-driven microbial ecosystems thought
to be characteristic of early Earth ecosystems such as those now
fossilized as stromatolites. We used a culture-independent molecular
phylogenetic approach to investigate the specific composition of a
hypersaline microbial mat in Guerrero Negro, Baja California Sur,
Mexico. This study is the first comprehensive survey of the microbial
diversity as a function of depth performed with molecular methods. I
will present the results of the 2500 rRNA sequence depth survey of the
mat, one of the largest environmental surveys conducted to date. The
overall diversity is exceedingly high, and the consistent dominance
with depth of the Green Non Sulfur bacteria is unexpected. I will also
present some of the ongoing imaging of the microbial community
structure revealed with laser confocal microscopy. This research is
part of the effort of the NASA Astrobiology Institute´s Ecogenomics
Focus Group to characterize the hypersaline microbial mats of Guerrero
Negro biologically and chemically

FAR Seminars