Paracoccus

Paracoccus bacteria are a soil microbe that can remove essential nutrients from the soil, consequently harming crop production. They can also cause a range of infections in humans of all ages.

Paracoccus
Paracoccus yeei colonies
Scientific classification
Kingdom:	Bacteria
Phylum:	Pseudomonadota
Class:	Alphaproteobacteria
Order:	Rhodobacterales
Family:	Rhodobacteracaea
Genus:	Paracoccus

Appearance

Paracoccus bacteria (Paracocci) are gram negative (negative result on the gram stain) and circle shaped (known as a coccus). Paracocci may also exist in pairs stuck together known as diplococci.

Classification

The genus Paracoccus is within the family Rhodobacteracaea and contains 31 species. The Rhodobacteracaea are within the order Rhodobacterales, in the class Alphaproteobacteria of phylum Pseudomonadota. Pseudomonadota is also sometimes referred to as Proteobacteria.

Habitat

Paracocci can live in a very wide range of habitats both on land and in the water. These include soils, seawater, freshwater, and even inside humans. Paracoccus bacteria do not have any way of moving themselves so will just float in the direction of the current.

Metabolism

Paracoccus bacteria are able to use a large variety of chemical compounds as energy. These include methanol and similar molecules, in addition to nitrogen rich molecules known as amines.

Effect on humans

The effects of these bacteria on humans are as diverse as the environments the live in. When in the soil, Paracoccus bacteria have a denitrifying effect where they release nitrate from the soil. This is bad for humans as crop plants need nitrate. Therefore, losing it results in a reduction in soil nutrients and a reduction in crop yields. The other issue is that the nitrate is released as nitrogen dioxide, nitric oxide, or nitrous oxide. All three are greenhouse gases which increase climate change when released.

Paracocci can also be the cause of skin, eye, ear, spine, blood, and wound (mostly on the feet or ankles) infections. However, they are considered low risk and are currently rare.

Paracoccus bacteria can potentially be beneficial to humans too. Since they can consume and break down amines, they could be used to clean up human pollution which is often amines (bioremediation). Bioremediation is where microbes or fungi are used to remove human pollution such as oil spills.

History

The genus Paracoccus was first proposed by Diane Davis in 1969 when dividing the Hydrogenomonas genus into new genera. At the time it only contained two species. Since then, the genus has been expanded by adding 29 other species