corrig. (Conn 1928) Conn and Dimmick 1947 (Approved Lists 1980)
Species
See text.
Arthrobacter (from the Greek, "jointed small stick”) is a genus of bacteria that is commonly found in soil. Members of the genus have also been reported from insect-associated environments, suggesting ecological roles beyond soil habitats[1]. All species in this genus are Gram-positiveobligate 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.
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).
