INVESTIGADORES
CUASSOLO Florencia
congresos y reuniones científicas
Título:
Life on floating pumice
Autor/es:
JAMES ELSER; JESSICA CORMAN; ZARRAZ LEE; JANET SIEFERT; MARCELA BASTIDAS NAVARRO; FLORENCIA CUASSOLO; CECILIA LASPOUMADERES; MARIA S. SOUZA; BEATRIZ MODENUTTI; ESTEBAN BALSEIRO
Reunión:
Conferencia; Astrobiology Science Conference; 2012
Resumen:
One
4 June 2011 a major eruption occurred in Puyehue-Cordón Caulle Volcanic
Complex (Chile; Figure 1A), ejecting massive amounts of ash and pumice
into the surrounding region, especially to the east and southeast in the
vicinity of Bariloche, Argentina. Indeed, the pumice formed massive
rafts in Lake Nahuel Huapi and other lakes that were visible from
satellite in the weeks after the eruption (see Figure 1B). These
floating pumice spherules provide unique, initially sterile, substrates
that should be colonized by microbes over time. If we saw such an image
from another world, would we recognize such islands as potential
microbial habitats? Furthermore, it has recently been hypothesized that
floating pumice may have provided a suitable substrate for the origin of
life itself(Brasier et al. 2011) but what is life like on floating
pumice? How do biota cope with environmental conditions and acquire the
necessary nutrients for growth and proliferation? The events in Chile
and Argentina have opened a window to allow us to answer these questions
and to gain knowledge of these unique Earth habitats. We sampled pumice
in these lakes from July 2011 until March 2012, preserving samples for
determination of microbial community composition (via DNA barcoding
approaches based on IonTorrent technology). Samples were taken in
several of the lakes at approximately monthly intervals for comparison
of successional changes and assessment of the similarity of the
communities in different lakes. We also assessed the kinetics of
nutrient (inorganic N and P) use via 15N-labeled NH4 and NO3 and
18O-labeled PO4 andprepared isotopically labeled samples for
visualization of nutrient utilization using Nano-SIMS. Finally, we
tested the effects of nutrient (P) amendment on microbial community
succession.This talk will involve a guided tour through the
pumice-impacted zone and present preliminary data from these ongoing
field studies.