Oceans are very complex ecosystem in which microorganisms play an important role in biogeochemical processes and in the cycling of matter. In the marine ecosystem all groups of microorganisms, including viruses, autotrophic and heterotrophic prokaryotes (bacteria and cyanobacteria), and autotrophic and heterotrophic eukaryotes are present. Bacteria and viruses represent the largest microbial group. In order to determine the role of bacteria in marine biogeochemistry is essential the knowledge of their taxonomy and their temporal and spatial distribution. Classical microbiology methods (cultivation on nutrient media), gave us generally some insight into the real image in this complex system. In the past 20 years, molecular microbiology, particularly culture independent methods and epifluorescence microscopy, in many ways has helped clarify their role. Many new species continue to be described and unexpected physiological and biochemical properties is determined. The increasing availability of complete genome and sequences of different marine bacteria species and new technologies for global analysis of the genome, proteome, transcriptome open new possibilities in the study of complex systems such as the sea. The Adriatic Sea is one of the best preserved of biological reserves in the Mediterranean, but still its undiscovered his microbial diversity. During the proposed project we will determine the temporal and spatial distribution of bacteria in the Adriatic Sea and their role in geochemical processes. On the other hand we want to study the genetic basis of adaptive differences. To achieve this aim will apply new technologies such as metagenomics and metatranscriptomics. Goals are also to determine their possible biotechnological applications of isolated bacteria and create a collection that is the basis for knowledge and preservation of microbial diversity of the Adriatic Sea.

UKF Grant Agreement No. 70/10

Project leader: Tina Šilović

Project co-leader: Dr. Carlos Pedrós-Alió

Administering organization: Rudjer Boskovic Institute, Center for marine research

Partner Institution/Company:Mediterranean Marine and Environmental Research Centre (CMIMA), Institute of Marine Sciences (ICM), Department of Marine Biology and Oceanography

Duration of the project: 01 October – 31 December 2010

Granted amount: 5.229,00 €

Summary: Picoeukaryotes (cells < 3 µm) contribute significantly to marine plankton biomass and productivity. Recent molecular studies have brought to light their wide diversity. Our knowledge of the diversity of eukaryotic picoplankton is very limited for Adriatic Sea, so developing methods for assessing and monitoring their ecology and diversity is essential for understanding their contribution in food web dynamics and biochemical cycles. The lack of data is due to technical difficulties in identifying and classifying picoplanktonic organisms with light microscopy, which clarifies need for new efficient tools in studying of these small organisms. Among the molecular methods that have been used so far DGGE has been proved as best compromise between the number of samples and information obtained.

Results: The main idea of this project was to test and validate DGGE as method that allow for routine assessment of picophytoplankton diversity  in the Adriatic sea. Our strategy to meet this objective was encapsulated in 3 months stay in hosting lab. In that period I was able to learn preparation of the samples  consisted of PCR amplification of 16S and 18S rRNA; preparation of DGGE gels, cutting gels for sequencing and intepretation of results. Some of the results were already presented at the hosting Institute during my stay (23rd of  November 2010. At 10 h. Sala S47a), which provided me an excellent opportunity for discussion with eminent experts from this field.

After final analysis results will be discussed in my doctoral thesis, scientific publications and public lecture at my Institute.

The cooperation with hosting organization was I must admit much better than I was expected. Their hospitality and good will to help in any moment when I needed assistance with processing of the samples or working with instrument or interpretation of results was really great. That level of healthy working spirit I must say its pretty rare.

I have gained great experience while working in this lab and I think that main benefit is not only my new skills gained from outstanding experienced researchers but as well establishment of future collaboration. Establishing working networks worldwide is surely one of the most important parts in increasing of international competitiveness of national scientific centers like Center for marine research.