Aquatic microbial ecology

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The research conducted by the Aquatic Microbial Ecology Lab of the CNR-ISE focuses on interactions and processes in the freshwater microbial food-web. Heterotrophic and autotrophic microorganisms are studied, taking into account their chemical and physical environment, and looking in particular at particulate and dissolved organic carbon, and underwater radiation. Research is performed in the field (1) on many different lakes such as deep subalpine lakes, ultra-oligotrophic North Patagonian lakes (Argentina), high altitude alpine and Himalayan lakes, and high altitude tropical lakes in Mexico; in laboratory-based experiments (2) on UVR effects on both heterotrophic and autotrophic microorganisms, on the impact of primary and emerging hidden interactions between microbes, and on the impact of antibiotics, or to test and model general ecological theories; and in-lake experiments (3) to measure microbial processes and interactions with organic substrate.

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Research

Field and laboratory activity:

1. Long-term trends of epilimnetic and hypolimnetic prokaryotic assemblages and of organic carbon in Lago Maggiore (included in Southern Alpine Lakes LTER site) (Fig. 1). Effects of climate change on the microbial food web.
2. Horizontal heterogeneity of seston, organic carbon and picoplankton in the photic zone of Lago Maggiore, Northern Italy.
3. Ecology of freshwater autotrophic picoplankton in the field and in microcosms. Isolation and identification of strains from lakes around the world. Evaluation of photosynthetic efficiency under different light/nutrient conditions.



4. Picoplankton diversity in deep oligotrophic subalpine lakes and in ultraoligotrophic Andean lakes. Role of UVR and of physical constraints on vertical distribution.
5. Production, biomass and diversity of picophytoplankton in temperate Alpine and Andean oligotrophic lakes and in tropical lakes.
6. Theoretical ecology, experimental microbial ecology on artificial communities. System ecology.
7. Direct and indirect effects of protist predation, competition, cooperation on population size structure, diversity and morphological distribution of bacteria.
8. Effect of UV radiation on bacteria and picocyanobacteria morphology: experimental approach on different genetically defined strains.
9. Microbial assemblage composition with in situ hybridization looking at Bacteria and Archaea domains (Fig. 2).