- Source: Echinamoeba thermarum
Echinamoeba thermarum is an extremely thermophilic amoeba species discovered in various hot springs worldwide. It is notable for its ability to thrive at high temperatures, with an optimal growth temperature of 50°C (122°F).
Taxonomy
E. thermarum is classified within the genus Echinamoeba based on morphology and SSU rRNA comparisons. Its species name, "thermarum," refers to its highly thermophilic lifestyle and hydrothermal habitat.
The phylogenetic analysis places Echinamoebida as a clade of thermophilic amoebae within Lobosa (Amoebozoa).
Habitat and distribution
E. thermarum was isolated from hot springs in multiple locations, including:
Agnano Terme, Italy
Yellowstone National Park, USA
Kamchatka, Russia
Arenal Volcano, Costa Rica
Additional locations have been identified by other researchers:
Black Canyon geothermal springs of the Colorado River, USA
Geothermal springs of Taupō Volcanic Zone, New Zealand
Karymsky Volcano and Valley of Geysers, Russia
The species has adapted to live in hydrothermal environments with temperatures ranging from 33°C (91.4°F) to 57°C (134.6°F).
Morphology and characteristics
E. thermarum morphological features are as follows:
Flat cells with irregular triangular or elongated shapes
Fine spine-like sub pseudopodia
Average size: 22 μm long and 11 μm wide
Single nucleus with a central nucleolus
The amoeba can be cultured monoxenically on a thermophilic alpha-proteobacterium.
Evolution and adaptation
E. thermarum as an example of adaptation to extreme environments suggests that the evolution of thermophily in amoebae has occurred across multiple distantly related lineages, indicating that the amoeboid form may be particularly well-suited for high-temperature environments.
E. thermarum and other thermophilic amoebae can provide insights into: adaptations enabling survival in hot conditions. The relationship between morphological form and thermophilic lifestyle. Functional contributions of thermophilic amoebae to extreme environment ecology.
Ecological significance
E. thermarum identified as a potential host for Legionella pneumophila, a pathogenic bacterium known to cause Legionnaires' disease. This relationship highlights the importance of understanding the ecology of thermophilic amoebae in both natural and engineered water systems.
