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SEM of Arthrobacter chlorophenolicus.jpg
Arthrobacter chlorophenolicus
Scientific classification
Kingdom: Bacteria
Phylum: Actinobacteria
Class: Actinobacteria
Order: Actinomycetales
Family: Micrococcaceae
Genus: Arthrobacter
Conn & Dimmick, 1947

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.

Colonies of Arthrobacter have a greenish metallic center on mineral salts pyridone broth incubated at 20 °C (68 °F). This genus is distinctive because of its unusual habit of "snapping division" in which the outer bacterial cell wall ruptures at a joint (hence its name). Microbiologists refer to the type of cell division in which rods break into cocci as reversion. Under the microscope, these dividing cells 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.

One species, A. crystallopoietes, has been shown to reduce hexavalent chromium levels in contaminated soil, suggesting that it may be useful in bioremediation.[1]

Arthrobacter chlorophenolicus sp. nov., a species capable of degrading high concentrations of 4-chlorophenol, may also be useful in bioremediation.[2] 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 sp H65-7 produces the enzyme inulase II that converts inulin into difructose anhydride (DFA). DFA is a promising nutrient for fighting osteoporis, because it helps absorption of calcium in the intestines.[citation needed]

The enzyme Alu obtained from Arthrobacter luteus is able to cleave Alu sequences in human DNA, causing the kind of gene sequence to be named after the enzyme. Alu are a group of moderately repetitive gene sequences (300bp in length). Alu sequences make up 6-8% of the human genome.[4]


  1. ^ F.A.O Camargo, F.M. Bento, B.C. Okeke, and 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. 
  2. ^ K Westerberg, AM Elvang, E Stackebrandt and 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: 2083–2092. doi:10.1099/00207713-50-6-2083. PMID 11155983. 
  3. ^ O'Loughlin, E. J., G.K. Sims, and S.J. Traina (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. 
  4. ^ Marks A. Basic Medical Biochemistry: a Clinical Approach 3ed, p. 248.

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