Group leader: Junior Prof. Sharmishtha Dattagupta

We use creative thinking to study physiological ecology and evolution of microbes, with a special focus on microbe-animal interactions (symbioses) and microbes living in unusual (from an anthropogenic perspective, "extreme") environments.

OUR STUDY LOCATIONS

Frasassi caves (central Italy)

The Frasassi cave system, located in the Marches region of north-central Italy, is a limestone cave complex that is actively forming due to dissolution by sulfuric acid. Groundwaters rich in the chemical hydrogen sulfide rise from a buried reservoir and interact with oxygen-rich cave air at the water table. Chemoautotrophic microbes oxidize the sulfide to produce sulfuric acid, and also use the energy to fix carbon. This supports a rich ecosystem containing several species of invertebrates including amphipods, isopods, copepods, ostracods, and oligochaetes. The Frasassi cave ecosystem is thus a freshwater analog for marine ecosystems driven solely by chemoautotrophy, found at deep-sea hydrothermal vents and methane/oil seeps.

Lonar lake (south-western India)

Lonar is a hypersaline (NaCl- 1.7%), hyperalkaline (pH ~ 10) lake filling a meteor impact crater located in the state of Maharashtra in south-western India. It is the only known example of hypervelocity meteor impact crater in basaltic rock, and was formed approximately 50,000 years ago.

OUR CURRENT RESEARCH TOPICS

1. Evolution of an ectosymbiosis between Frasassi cave-dwelling Niphargus amphipods and filamentous sulfur-oxidizing Thiothrix bacteria

Relevant publications:
Flot, J-F., Wörheide, G., and Dattagupta, S. (2010) Unsuspected diversity of Niphargus amphipods in the chemoautotrophic cave ecosystem of Frasassi, central Italy. BMC Evolutionary Biology, 10: 171–184. Open access article available at http://www.biomedcentral.com/1471-2148/10/171

Dattagupta, S., Schaperdoth, I., Montanari, A., Mariani, S., Kita, N., Valley, J. W. and Macalady, J. L. (2009) A novel symbiosis between chemoautotrophic bacteria and a freshwater cave amphipod. The ISME Journal, 3: 935–943.

2. Gut symbioses in Frasassi cave-dwelling Niphargus amphipods

3. Nitrogen fixation in the Frasassi cave ecosystem

4. Physiological adaptations to hyperalkalinity of microorganisms living in Lonar lake sediments