ACL: Advent of Complex Life - MIT Astrobiology Team

Linda Amaral-Zettler
Assistant Scientist, Josephine Bay Paul Center for Comparative Molecular Biology and Evolution
Marine Biological Laboratory
E-mail: amaral at mbl dot edu
Website link: http://amarallab.mbl.edu

Assistant Professor, Brown-MBL Joint Graduate Program
Ecology and Evolutionary Biology
Brown University
Providence, RI 02912

Research Interests

Astrobiology research in the Amaral-Zettler Laboratory focuses on the extremely acidic, heavy metal rich terrestrial Mars analogue, the Río Tinto (RT) in southwestern Spain, and integrates both field and lab-based investigations. The Amaral-Zettler Laboratory currently maintains a collection of extremophilic protist cultures isolated from the RT that has enabled collaborative research in physiology and comparative molecular biology of key microbial eukaryotes inhabiting the RT. The RT is an interesting ecosystem in that while sulfur cycling is important, the iron cycle plays the central role in both chemolithotrophy and maintenance of the extreme conditions in the river. Primary production is dominated by photosynthetic eukaryotes that form conspicuous blooms in parts of the river and often dominate the microbial biomass.

Questions that drive current research include:

1. What accounts for patterns in microbial diversity seen in the extreme RT environment?
2. What community assembly rules drive patterns of microbial diversity found in the RT -including blooms of eukaryotic algae that dominate biomass in parts of the river?
3. Can we predict what species we will find given a set of geochemical conditions? Can we predict what geochemistry we will find given knowledge of the membership of a microbial assemblage?
4. Do phylogenetically diverse protists possess distinct mechanisms for coping with pH and heavy metal extremes?

The Amaral-Zettler Laboratory has been addressing these questions using a combination of molecular approaches including Serial Analysis of Ribosomal Sequence Tags (SARST-V6), rRNA gene clone library surveys, and 454 pyrosequencing. Work in the RT began as part of a collaboration with Ricardo Amils (Autonomous University of Madrid/Centro de Astrobiología) in 1999 as an NIH postdoctoral project in the Sogin Laboratory and has continued through funding via the NSF Life in Extreme Environments followed by funding to the MBL via the NASA Astrobiology Institute. Current research with the Centro de Astrobiología in Spain comes via a collaborative research project with Angeles Aguilera entitled, "Mecanismos de adaptación de la comunidad microbiana eucariota en ambientes ácidos extremos. Resistencia a metales pesados y su aplicación en biorremediación (BIOTEC)."