Taxonomy
- Domain: Bacteria
- Phylum: Proteobacteria
- Class: Betaproteobacteria
- Order: Burkholderiales
- Family: Comamonadaceae
- Genus: Comamonas
- Species: Comamonas terrigena
Nomenclature
The species epithet terrigena derives from Latin, meaning “originating from the earth/soil,” reflecting the typical habitat from which the bacterium was first isolated.
Morphology and Physiology
- Gram‑negative, rod‑shaped bacteria, typically 0.5–0.8 µm in width and 1.5–2.5 µm in length.
- Motile by a single polar flagellum.
- Aerobic or facultatively anaerobic, capable of oxidizing a range of organic compounds.
- Catalase‑positive and oxidase‑positive.
Ecology
Comamonas terrigena has been isolated from diverse soil environments, including agricultural fields and forest litter. It participates in the degradation of organic pollutants and can utilize compounds such as phenol, benzoate, and various short‑chain fatty acids as carbon sources.
Genomic Characteristics
- Genome size reported to be in the range of 4.5–5.0 Mbp, with a G+C content of approximately 66 mol%.
- Genes encoding enzymes for aromatic compound degradation (e.g., catechol 1,2‑dioxygenase) are commonly present.
Clinical Relevance
There are limited reports of C. terrigena as an opportunistic pathogen in humans. While members of the Comamonas genus have been isolated from clinical specimens (e.g., blood, wound exudates), C. terrigena is not prominently associated with disease and is generally considered of low pathogenic potential.
Biotechnological and Environmental Applications
- Bioremediation: Due to its ability to degrade phenolic and aromatic pollutants, C. terrigena is of interest for the cleanup of contaminated soils and waters.
- Wastewater treatment: Its metabolic versatility makes it a candidate for inclusion in microbial consortia designed to treat industrial effluents.
Isolation and Identification
Standard isolation involves culturing soil suspensions on non‑selective media such as R2A agar under aerobic conditions. Identification relies on a combination of phenotypic tests, fatty‑acid methyl‑ester (FAME) profiling, and molecular methods (16S rRNA gene sequencing) that place the isolate within the Comamonas clade and confirm species identity through >98 % sequence similarity to reference strains.
References
(Information summarized from peer‑reviewed microbiology literature and taxonomic databases such as LPSN, NCBI Taxonomy, and Bergey’s Manual of Systematic Bacteriology.)
