Cave ice microbiom: metabolic diversity and activity in response to climate dynamics and anthropogenic pollution

Publishable summary: 

The overall interest of the project is to characterize the diversity and metabolism of total and active microcosm from cave ice, and evaluate past, present and future consequences of climate driven ice retreat and human impact on biogeochemical and ecological processes by studying temporal and spatial changes in ecosystems present in ice and glacier caves from different geographical locations, and to establish a strategic framework for multidisciplinary research in ice ecosystems, including investigation of the applicative potential of ice microcosm in nanotechnology development.

The goals of the project are i) the first characterization of the functional diversity and activity of a cave ice microbiome using metagenomic and metatranscriptomic Next Generation Sequencing, ii) to assess the impact of climate dynamics and anthropogenic pollution on microbial communities preserved in this particular glacier environment, and iii) to identify novel cold adapted metal nanoparticle producing strains for bionantotechnologies. The project started in 2016 and accomplished the main objectives and activities emphasized for this period. Ice samples were collected from the Europe and South American locations, including the glacier caves from Argentina (Viedma Glacier) and Chile (Grey Glacier), and the from the ice caves from Norway (Svarthammar), Romania (Scǎrişoara) and Slovakia (Dobšinská and Demänovska) with the participation of all the consortium teams. Physicochemical and geochemical analyses were carried out on Scǎrişoara ice of up to 2000 years old. Recent climate analysis of Scǎrişoara was initiated and carried out by long-term monitoring of water isotopic composition outside and inside the cave. Samples from the ice block of Svarthammar were collected for stable isotope analyses (432) and for 14C dating (14). Microbial DNA was extracted from the ice samples collected from all locations for determining the bacterial diversity; for Svarthammar ice samples, this step will be carried out in January 2017 with the participation of a Master student from the Romanian IBB partner in Norway UoB laboratory. Illumina sequencing of 16S rDNA was performed for samples collected from Grey Glacier dominated by Firmicutes and Bacteroidetes, while 454 pyrosequencing of five ice samples of Scarisoara showed the presence of Proteobacteria, Firmicutes and Actinobacteria in ice of up to 900 years old, a high representation of Bacteroidetes and Cyanobacteria in recent ice exposed to light, and the presence of Archaea in 400 and 900 years old ice. Shotgun metagenomics sequencing of 7 ice samples of up to 2000 years old from Scarisoara cave is in progress. Bacterial cultures and isolated colonies were obtained from Scarisoara ice cave and Grey Glacier ice samples and their identification based on 16S rDNA is currently underway.

Two CAVICE kick -off meetings were organized in Argentina and Slovenia, respectively, to ensure the participation of all the European and Latin American consortium partners for discussing a series of scientific and management collaborative aspects. CAVICE results were presented in three conferences (4 oral presentations and 4 posters), with the participation of members of 4 of the consortium partners. This project is expected to provide pioneering knowledge on cave ice microcosm reflected in a better understanding of how the ice microbiomes mirrors the past and actual climate changes and the anthropogenic activities. We appreciate that this study will contribute to the knowledge for predicting the dynamics and evolution of the ice microbiomes in relation with the climatic patterns and anthropogenic pollution. Identification of pollution biomarkers would ease the monitoring activities, being of great help for the caves administrations in their effort to better preserve these unique sites. The novel cold adapted microorganisms able to synthesize metal nanoparticles that we attempt to identify are of broad applicative potential in nanotechnologies and medicine. This interdisciplinary project brings together specialists from various fields of Life Sciences, thus ensuring the improvement of the scientific level of the participating teams, and favoring further joint applications. Moreover, the project contributes to the formation of top -rank young scientists through an excellent training of the participant Master students and PhD students.