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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Crop Bioprotection Research » Research » Publications at this Location » Publication #393697

Research Project: Develop an Improved Understanding of Microbe-pathogen Interactions for Biological Control

Location: Crop Bioprotection Research

Title: Genomic analysis of heavy metal-resistant Halobacterium salinarum isolated from Sfax solar saltern sediments

item BAATI, HOUDA - University Of Sfax
item SIALA, MARIEM - University Of Sfax
item AZRI, CHAFAI - University Of Sfax
item AMMAR, EMNA - University Of Sfax
item Dunlap, Christopher
item TRIGUI, MOHAMED - University Of Sfax

Submitted to: Extremophiles
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/30/2022
Publication Date: 7/16/2022
Citation: Baati, H., Siala, M., Azri, C., Ammar, E., Dunlap, C.A., Trigui, M. 2022. Genomic analysis of heavy metal-resistant Halobacterium salinarum isolated from Sfax solar saltern sediments. Extremophiles. 26. Article 25.

Interpretive Summary: An ARS researcher from Peoria, IL, collaborated with scientists from a University in Tunisia to characterize the genomes of five strains of Halobacterium salinarum. The strains of Halobacterium salinarum were isolated from a high salt environment and shown to have heavy metal tolerance. Understanding how microbes survive in extreme environments can lead us to the develop strategies that allow agriculturally important microbes and plants to adapt to these conditions. High salt contamination is a significant problem worldwide in irrigated agricultural lands. The current study explored the genomes of these strains to identify genes associated with stress tolerance. The results showed that these strains contained multiple copies of genes associated with tolerance to salt and heavy metals. These results will be used to guide further studies on how these strains adapt to high salt and heavy metal ion conditions.

Technical Abstract: The draft genome sequences of five archaeal strains, isolated from Sfax solar saltern sediments and affiliated with Halobacterium salinarum, were analyzed in order to reveal their adaptive strategies to live in hypersaline environments polluted with heavy metals. The genomes of the strains (named AS1, AS2, AS8, AS11, and AS19) are found to contain 2,060,688; 2,467,461; 2,236,624; 2,432,692; and 2,428,727 bp respectively, with a G+C content of 65.5, 66.0, 67.0, and 66.2%. The majority of these genes (43.69-55.65%) are annotated as hypothetical proteins. Growth under osmotic stress is possible by genes coding for potassium uptake, sodium efflux, and kinases, as well as stress proteins, DNA repair systems, and proteasomal components. These strains harbor many genes responsible for metal transport/resistance such as: copper-translocating P-type ATPases, ABC transporter, and cobalt-zinc-cadmium resistance protein. Additionally, detoxification enzymes and secondary metabolites are also identified. The results show strain AS1, compared to the other strains, is more adapted to heavy metals and may be used in the bioremediation of multi-metal contaminated environments. This study highlights the presence of several commercially valuable bioproducts (carotenoids, retinal proteins, exopolysaccharide, stress proteins, squalene, and siderophores) and enzymes (protease, sulfatase, phosphatase, phosphoesterase, and chitinase) that can be used in many industrial applications.