Acinetobacter calcoaceticus

Acinetobacter calcoaceticus is a species of bacteria belonging to the genus Acinetobacter. It is a non-motile, Gram-negative coccobacillus that is commonly found in soil and water environments. A. calcoaceticus is known for its ability to degrade a wide range of organic compounds, making it of interest in bioremediation and biotechnology.

Morphology and Physiology

Acinetobacter calcoaceticus is a Gram-negative bacterium, which means it does not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. It appears as a coccobacillus, which is a short rod-shaped bacterium. The cells are typically 1.0 to 1.5 micrometers in length and 0.6 to 1.0 micrometers in width.

This bacterium is non-motile, lacking flagella, and does not form spores. It is an aerobic organism, requiring oxygen for growth, and it can grow at temperatures ranging from 20°C to 37°C. A. calcoaceticus is oxidase-negative and catalase-positive, which are important characteristics used in its identification.

Genomic Characteristics

The genome of Acinetobacter calcoaceticus has been sequenced, revealing a circular chromosome with a size of approximately 3.9 million base pairs. The genome encodes a variety of enzymes that enable the bacterium to metabolize a wide range of substrates, including aromatic compounds, aliphatic hydrocarbons, and alcohols.

Ecology and Habitat

Acinetobacter calcoaceticus is ubiquitously found in the environment, particularly in soil and water. It is also present in hospital settings, where it can be isolated from surfaces and medical equipment. The bacterium's ability to survive in diverse environments is attributed to its metabolic versatility and resistance to desiccation.

Bioremediation Potential

Acinetobacter calcoaceticus is of significant interest in the field of bioremediation due to its ability to degrade a variety of pollutants. It can metabolize hydrocarbons, phenols, and other toxic compounds, making it useful in the cleanup of contaminated sites. The bacterium's enzymes, such as monooxygenases and dioxygenases, play a crucial role in the breakdown of these compounds.

Clinical Significance

While Acinetobacter calcoaceticus is primarily an environmental organism, it can occasionally be associated with nosocomial infections, particularly in immunocompromised patients. It is often found in mixed infections and can be resistant to multiple antibiotics, complicating treatment.

Laboratory Identification

In the laboratory, Acinetobacter calcoaceticus can be identified through a combination of morphological, biochemical, and molecular techniques. The bacterium grows well on standard media such as nutrient agar and MacConkey agar. Biochemical tests, including the oxidase test and catalase test, are used to differentiate it from other bacteria. Molecular methods, such as 16S rRNA sequencing, provide definitive identification.

Industrial Applications

Beyond bioremediation, Acinetobacter calcoaceticus has potential applications in biotechnology. It can be used in the production of biopolymers, biosurfactants, and other valuable compounds. Its ability to transform and degrade complex organic molecules is harnessed in various industrial processes.

See Also

• Acinetobacter
• Bioremediation
• Nosocomial infection

External Links

• [Acinetobacter calcoaceticus Genome Database]
• [Bioremediation Research on Acinetobacter]