Arthrobacter (from the Greek, "jointed small stick”) is a genus of bacteria that is commonly found in soil. All species in this genus are Gram-positive obligate aerobes that are rods during exponential growth and cocci in their stationary phase. Arthrobacter have a distinctive method of cell division called "snapping division" or reversion in which the outer bacterial cell wall ruptures at a joint.

Arthrobacter
Arthrobacter chlorophenolicus
Scientific classification Edit this classification
Domain: Bacteria
Phylum: Actinomycetota
Class: Actinomycetia
Order: Micrococcales
Family: Micrococcaceae
Genus: Arthrobacter
Conn and Dimmick 1947 (Approved Lists 1980)
Type species
Arthrobacter globiformis
corrig. (Conn 1928) Conn and Dimmick 1947 (Approved Lists 1980)
Species

See text.

Description

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Arthrobacter can be grown on mineral salts pyridone broth, where colonies have a greenish metallic center on incubated at 20 °C (68 °F). Under the microscope, Arthrobacter appear as rods when rapidly dividing, and cocci when in stationary phase. Dividing cells may also appear as chevrons ("V" shapes). Other notable characteristics are that it can use pyridone as its sole carbon source, and that its cocci are resistant to desiccation and starvation.

Use in industry

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Arthrobacter, like other bacterial genera including Brevibacterium, Microbacterium, and Corynebacterium are used for industrial production of L-glutamate. In industrial applications, Arthrobacter is often grown with low-cost sugar sources such as cane or beet molasses, starch hydrolysates from corn or cassava tubers, or tapioca. Along with sugar, ammonia and ammonium salts are added as a nitrogen source. The vitamins, minerals, and some other types of nutrients can be provided by adding corn steep liquour.

Other uses

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Various Arthrobacter species have been investigated for other commercial applications. A. crystallopoietes and A. chlorophenolicus have been shown to reduce hexavalent chromium and 4-chlorophenol levels in contaminated soil, suggesting they may be useful for bioremediation.[1][2] Similarly, Arthrobacter sp. strain R1 (American Type Culture Collection strain number 49987) has been shown to grow on a variety of aromatic compounds, including homocyclic compounds, such as hydroxybenzoates, as well as N-heterocycles, including pyridine and picoline.[3]

 
Arthrobacter crystallopoietes produces a pigment when grown on 2-pyridone (right) but not when grown on succinic acid (left).

Arthrobacter sp. H65-7 produces the enzyme inulase II that converts inulin into the medically relevant nutrient difructose anhydride.[4]

The enzyme Alu obtained from Arthrobacter luteus is able to cleave Alu sequences which is frequently repeated in human DNA.[5]

Species

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Arthrobacter comprises the following species:[6]

References

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  1. ^ F.A.O. Camargo; F.M. Bento; B.C. Okeke & W.T. Frankenberger (2003). "Hexavalent chromium reduction by an actinomycete, Arthrobacter crystallopoietes ES 32". Biological Trace Element Research. 97 (2): 183–194. doi:10.1385/BTER:97:2:183. PMID 14985627. S2CID 22649567.
  2. ^ K Westerberg; AM Elvang; E Stackebrandt; JK Jansson (2000). "Arthrobacter chlorophenolicus sp. nov., a new species capable of degrading high concentrations of 4-chlorophenol". International Journal of Systematic and Evolutionary Microbiology. 50 (6): 2083–2092. doi:10.1099/00207713-50-6-2083. PMID 11155983.
  3. ^ O'Loughlin EJ, Sims GK, Traina SJ (1999). "Biodegradation of 2-methyl, 2-ethyl, and 2-hydroxypyridine by an Arthrobacter sp. isolated from subsurface sediment". Biodegradation. 10 (2): 93–104. doi:10.1023/A:1008309026751. PMID 10466198. S2CID 25495834.
  4. ^ Sakurai, Hiroaki; Yokota, Atsushi; Tomita, Fusao (2014). "Molecular Cloning of an Inulin Fructotransferase (Depolymerizing) Gene from Arthrobacter sp. H65–7 and Its Expression in Escherichia coli". Bioscience, Biotechnology, and Biochemistry. 61 (1): 87–92. doi:10.1271/bbb.61.87. PMID 9028036.
  5. ^ Marks A. Basic Medical Biochemistry: A Clinical Approach (3rd ed.). p. 248.
  6. ^ Euzéby JP, Parte AC. "Arthrobacter". List of Prokaryotic names with Standing in Nomenclature (LPSN). Retrieved June 14, 2022.
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