Arthrobacter

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
Domain:	Bacteria
Phylum:	Actinobacteria
Class:	Actinobacteria
Order:	Actinomycetales
Family:	Micrococcaceae
Genus:	Arthrobacter Conn & Dimmick, 1947
Species
Arthrobacter agilis[1] Arthrobacter alkaliphilus[1] Arthrobacter alpinus[1] Arthrobacter bambusae[1] Arthrobacter castelli[1] Arthrobacter citreus[1] Arthrobacter cryoconiti[1] Arthrobacter crystallopoietes[1] Arthrobacter cupressi[1] Arthrobacter deserti[1] Arthrobacter echini[1] Arthrobacter enclensis[1] Arthrobacter endophyticus[1] Arthrobacter flavus[1] Arthrobacter gandavensis[1] Arthrobacter globiformis[1] Arthrobacter ginkgonis[1] Arthrobacter gyeryongensis[1] Arthrobacter halodurans[1] Arthrobacter humicola[1] Arthrobacter koreensis[1] Arthrobacter liuii[1] Arthrobacter livingstonensis[1] Arthrobacter luteolus[1] Arthrobacter methylotrophus[1] Arthrobacter monumenti[1] Arthrobacter nanjingensis[1] Arthrobacter nasiphocae[1] Arthrobacter oryzae[1] Arthrobacter paludis[1] Arthrobacter parietis[1] Arthrobacter pascens[1] Arthrobacter pigmenti[1] Arthrobacter pityocampae[1] Arthrobacter pokkalii[1] Arthrobacter psychrochitiniphilus[1] Arthrobacter psychrolactophilus[1] Arthrobacter ramosus[1] Arthrobacter rhombi[1] Arthrobacter roseus[1] Arthrobacter ruber[1] Arthrobacter russicus[1] Arthrobacter sanguinis[1] Arthrobacter silviterrae[1] Arthrobacter stackebrandtii[1] Arthrobacter subterraneus[1] Arthrobacter tecti[1] Arthrobacter tumbae[1] Arthrobacter viscosus[1] Arthrobacter woluwensis[1]
Synonyms
Siderocapsa Dubinina and Zhdanov 1975

Description

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

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

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.[2][3] 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.[4]

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.[5]

The enzyme Alu obtained from Arthrobacter luteus is able to cleave Alu sequences which is frequently repeated in human DNA.[6]

References

1. LPSN
2. 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.
3. 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.
4. 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.
5. Sakurai, Hiroaki; Yokota, Atsushi; Tomita, Fusao (2014). "Molecular Cloning of an Inulin Fructotransferase (Depolymerizing) Gene from Arthrobactersp. H65–7 and Its Expression in Escherichia coli". Bioscience, Biotechnology, and Biochemistry. 61: 87. doi:10.1271/bbb.61.87.
6. Marks A. Basic Medical Biochemistry: a Clinical Approach 3ed, p. 248.

External links

• Arthrobacter Genome Projects (from Genomes OnLine Database)
• Comparative Analysis of Arthrobacter Genomes (at DOE's IMG system)