Survival of haloarchaea in the halite deposits in the Dead Sea basin.
Supervised by: Professor Terry McGenity
Project Duration: 13 months (2022-23)
Worked as: 5 months (M.Sc. student) + 8 months (Research Assistant)
At: University of Essex
Funded by: EU Horizon and University of Essex
This research aimed to isolate and characterize viable haloarchaea species from 40-year-old halite deposits precipitated in the Dead Sea. The primary objective was to uncover the survival mechanisms employed by these extremophiles in highly saline and ancient environments. Additionally, the study sought to explore the broader implications of these findings for biogeochemical processes on Earth and the potential for life in extraterrestrial environments with low water activity, such as Mars and Europa.
Approach and techniques used
To achieve the objectives of this study, a multidisciplinary approach combining microbiology, bioinformatics, and molecular biology was employed:
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Sample Collection and Isolation: Halite samples precipitated in 1983 from the Dead Sea were analyzed. A novel isolation medium was developed to optimize the recovery of haloarchaea based on the physiochemical properties of the Dead Sea.
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16S rRNA Gene Sequencing and Phylogenetic Analysis: The isolated strains were characterized by amplifying and sequencing the 16S rRNA gene. The phylogenetic relationships of these strains were constructed by comparing gene sequences from the LPSN database, ensuring comprehensive coverage of Haloarchaea families.
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Whole Genome Sequencing (WGS): Whole genome sequencing (WGS) was performed using Illumina technology to investigate the genomic diversity of the strains. The genome was annotated using the BV-BRC genome annotation tool to identify metabolic pathways and potential survival strategies.
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Proteome Analysis Pipeline: A bioinformatics pipeline was established to perform objective-oriented proteome analysis, utilizing various analytical instruments and tools to assess protein expression under hypersaline conditions.
Output and Impact
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Isolation and identification of 23 strains of Haloarchaea from the Dead Sea halite deposited in different years during last 40 years.
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Genome annotation revealed unique metabolic pathways in some strains, particularly in a new species of Salarchaeum.
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Two publications are under consideration due to the significant findings of this project.
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This research was presented at two international conferences, contributing to the growing body of knowledge on extremophiles and their potential applications.
SIGNIFICANCE & IMPACT
This study sheds light on the survival mechanisms of haloarchaea in hypersaline environments over extended geological time scales, providing insights into how life can persist in extreme conditions. The findings have broad implications for:
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Geobiology: The research offers a better understanding of microbial resilience and biogeochemical processes in salt-dominated ecosystems, contributing to the study of extremophiles in Earth’s most inhospitable environments.
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Astrobiology: By demonstrating how life can survive in extreme, low-water-activity environments like the Dead Sea, this research suggests that similar microbial life might exist on extraterrestrial bodies such as Mars or Europa, where water activity is low but stable.
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Educational Impact: Additionally, the research contributed to the development of a microbiology teaching framework for youth, utilizing sports as a medium for scientific engagement. This effort is part of a broader initiative to inspire the next generation of scientists.
Relevant Publication
Dhiman, U.; Magliulo, M.; Lensky, N.G.; McGenity, T.J. (2024). Survival of haloarchaea in 40-year-old halite deposits in the Dead Sea basin. [Under revision for Geobiology journal]
Dhiman, U.; Magliulo, M.; Lensky, N.G.; McGenity, T.J. (2024). Salarchaeum zombiensis novel sp., an aerobic, extremely halophilic member of the Archaea isolated from surface sterilised halite from the Dead Sea. To be submitted in International Journal of Systematic and Evolutionary Microbiology [Under write-up]