Gemmatimonadetes

Gemmatimonadetes

Gemmatimonadetes is a phylum of bacteria that is part of the domain Bacteria. This phylum is relatively less studied compared to other bacterial phyla, but it is known to be widespread in various environments, including soil, freshwater, and marine ecosystems.

Characteristics

Gemmatimonadetes are Gram-negative bacteria, which means they have a thin peptidoglycan layer and an outer membrane containing lipopolysaccharides. They are non-spore-forming and typically rod-shaped. Members of this phylum are known for their ability to survive in oligotrophic (nutrient-poor) environments.

Taxonomy

The phylum Gemmatimonadetes currently includes a few classes, with the most well-known being the class Gemmatimonadetes. Within this class, the order Gemmatimonadales and the family Gemmatimonadaceae are recognized. The type genus of this family is Gemmatimonas.

Notable Genera

• Gemmatimonas: The type genus of the phylum, with Gemmatimonas aurantiaca being a well-studied species.

Ecology

Gemmatimonadetes are found in a variety of environments, including:

• Soil: They are often detected in soil samples, where they contribute to the microbial community structure.
• Freshwater: They have been isolated from freshwater lakes and rivers.
• Marine environments: Some members have been found in oceanic environments.

These bacteria are thought to play a role in the carbon cycle and nitrogen cycle, although their specific ecological functions are not fully understood.

Metabolism

Gemmatimonadetes are generally aerobic, meaning they require oxygen for growth. They are heterotrophic, obtaining their energy from organic compounds. Some studies suggest that they may have the ability to perform anoxygenic photosynthesis, although this is not yet fully confirmed.

Research and Importance

Research on Gemmatimonadetes is ongoing, with scientists interested in their potential applications in bioremediation and their role in nutrient cycling. Their ability to thrive in low-nutrient environments makes them of particular interest for studies on microbial survival and adaptation.

References

• Zhang, H., Sekiguchi, Y., Hanada, S., Hugenholtz, P., Kim, H., Kamagata, Y., & Nakamura, K. (2003). Gemmatimonas aurantiaca gen. nov., sp. nov., a Gram-negative, aerobic, polyphosphate-accumulating micro-organism, the first cultured representative of the new bacterial phylum Gemmatimonadetes phyl. nov. International Journal of Systematic and Evolutionary Microbiology, 53(4), 1155-1163.
• DeBruyn, J. M., Nixon, L. T., Fawaz, M. N., Johnson, A. M., & Radosevich, M. (2011). Global biogeography and quantitative seasonal dynamics of Gemmatimonadetes in soil. Applied and Environmental Microbiology, 77(17), 6295-6300.