2 pages, 1 figure, 5 references. Pertenece al capítulo Symposium 5: Geomicrobiology of cave and karst environments.-- Simposio celebrado del 19 al 26 de julio, 2009, en Kerrville, Texas, U.S.A.Microorganisms play critical roles in biogeochemical processes. In caves, carbonate deposition constitutes
a common process. Although microorganisms able to induce these deposits have been previously
reported, little information is available on the microorganisms involved, their activity, and the conditions
required for the process to occur. This study presents results on the induction of carbonate precipitation
and dissolution by microorganisms. RNA-based molecular fingerprinting procedures were used for
profiling the metabolically active bacterial communities involved in the preliminary stages of moonmilk
deposits. Bacteria were cultured and isolated to analyze the required conditions and nutrients inducing
these depositions. Bacteria were able to differentially induce carbonate precipitation depending on the
nutrients available for growth. In addition, similar microorganisms can be involved in precipitation and
dissolution of carbonates mainly depending on the available nutrient sources. These results suggest the
existence of an active carbon cycling process in caves dominated by microorganisms.This research was supported by CGL2006-1 1561/BTE
project.Peer reviewe
