Microbial Eukaryotes of Croatian Hot springs

While geothermal waters in Croatia have been explored for their prokaryotic communities, comprehensive investigations into microbial eukaryotes are lacking. This study seeks to thoroughly characterize the microbial eukaryotic composition within Croatian geothermal waters and elucidate the pivotal abiotic factors that mold the community structure. We have conducted an in-depth examination of 14 distinct sites situated in continental Croatia, employing 18S rRNA gene amplicon sequencing techniques. Our findings reveal that the geothermal waters of Croatia are home to a multifaceted and diverse community encompassing microalgae, mixotrophs, decomposers, heterotrophic organisms, and parasites. It is evident that the configuration of the eukaryotic community is intricately linked to various environmental parameters, prominently including temperature, pH levels, and nitrate concentrations. Furthermore, the microalgae residing in these geothermal waters hold significant biotechnological potential. A subset of these microorganisms exhibits invaluable attributes, such as the possession of thermostable enzymes, rapid growth rates, and proficient carbon dioxide fixation capabilities. These qualities render them auspicious candidates for applications in bioremediation processes, biofuel production, and initiatives dedicated to environmental preservation. In summation, our research sheds light on the previously underexplored realm of microbial eukaryotes inhabiting Croatian hot springs. It accentuates their ecological significance and underscores their potential in the realm of biotechnology, thereby establishing a foundation for forthcoming investigations into their seasonal dynamics and the environmental determinants governing their existence within these extreme ecosystems.