ИСТИНА

This project proposes a cooperative research between the Dept. of Biotechnology at Delft University and the Winogradsky Institute of Microbiology in Moscow on the microbial adaptation to extremely high salinity and pH. Hypersaline lakes with neutral and extremely high pH located in Central Asia will serve as model habitat and the bacteria participating in sulfur and nitrogen cycles (sulfur oxidation, sulfur reduction and sulfur-dependent denitrification) will be used as model organisms. The adaptation of these bacteria to extreme conditions shall be investigated at different levels: 1) the community level, (2) the cell level, and (3) the molecule level. At the community level we will investigate community activity using radiolabelled substrates as an indicator of microbial activity under extreme conditions. Furthermore, we will determine the biodiversity, including populational, taxonomic, molecular and functional diversity as an indicator of structural maturity and stability of the microbial community. For the next level, i.e. the cell level, we will isolate and characterize key species, and will study their growth and activity at extremely high salt concentrations and pH. In addition, we will follow their physiological responses to changes in chemical composition of the brines. Investigation of the biochemical/boenergetic mechanisms of bacterial adaptations to high salt and/or high pH, including different enzymes, energy transforming mechanisms and respiratory chain belongs to the third level of investigation, i.e. the molecule level. Special attention shall be given to differences in adaptation strategy between extremely halophilic neutrophilic and haloalkaliphilic bacteria. The results of these study might be important both for a basic understanding of life at extreme conditions, and for the potential application of these bacteria in certain industrial processes, such as the removal of sulfur compounds from flue gas.