Poly-extremophiles include microorganisms that are adapted to thrive in environments where multiple extreme conditions coexist, such as intense heat, high salinity, extreme acidity or alkalinity, high pressure, or high levels of radiation. Unlike extremophiles that contend with a single stressor, poly-extremophiles demonstrate the capacity to survive and function amidst two or more intersecting environmental extremes simultaneously. This resilience is observed in microbial communities inhabiting poly-extreme settings, for example: deep-sea hydrothermal vents that combine high temperature, elevated pressure, and toxic metal concentrations; hypersaline acidic lakes where saturated salinity meets low pH conditions; and high-altitude deserts marked by intense UV radiation, desiccation, and low temperature.

Microorganisms that have evolved in these environments, such as Thermococcus gammatolerans—capable of withstanding extreme heat and radiation; Halarchaeum acidilutequum from hypersaline acidic lakes; and radiation- and desiccation-tolerant Deinococcus species, represent examples of poly-extremophilic adaptation. Recent progress in genomic technologies and innovative culturing methods is beginning to unveil this hidden diversity. However, a comprehensive understanding of their taxonomy, metabolism, biosynthetic potential, and ecological roles is still lacking.

This Research Topic is dedicated exclusively to the exploration of microorganisms that thrive under multiple, co-occurring extreme conditions, by integrating advanced sampling and culturing techniques with cutting-edge genomic approaches, including metagenomics and single-cell genomics. Our goal is to expand current knowledge of known microorganisms and discover novel microbial taxa, investigating their unique physiological traits, functional capabilities, and evolutionary strategies. Insights gained from this research will enhance our understanding of life’s adaptability and resilience across poly-extreme conditions, while also supporting potential applications in biotechnology, environmental innovation, and astrobiology.

We welcome submissions of Original Research, Reviews, Methods, Perspectives, and Opinion articles addressing, but not limited to, the following topics:

• Novel strategies for sampling, isolating, and culturing extremophiles under multiple extreme conditions;

• Advances in metagenomic and single-cell genomic approaches applied to studying poly-extremophiles;

• Biosynthetic potential and secondary metabolite production in poly-extreme microbial communities;

• Practical applications of poly-extremophile species in environmental remediation, innovative technologies, and astrobiology;

• Evolutionary mechanisms enabling microbial life to persist under multiple extreme conditions.

Are you interested in contributing a manuscript to this Research Topic?

Microbial Diversity and Survival in Poly-Extreme Environments