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Revision as of 02:49, 4 May 2018 by Melissa.winkler (talk | contribs) (Physiology and Pathogenesis)
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Domain: Bacteria

Phylum: Actinobacteria

Class: Actinobacteria

Order: Actinomycetales

Family: Micrococcaceae

Genus: Arthrobacter

Species: protophormiae


NCBI: Taxonomy [1]

Arthrobacter protophormiae

Habitat Information

The location in which the soil sample was obtained is in Austin, Texas, at the ACC Riverside campus, between two buildings. The exact GPS coordinates for this location are 30.237284, -97.704893. Collection was done around noon on January 26, 2018. The temperature was 57 degrees F with 81% humidity and 30.23 in of pressure. Winds were directed North and there was a slight overcast. It did not rain that day, However, it had rained five days prior. Soil was collected approximately two inches from the surface to eliminate as many rocks as possible.

Description and Significance

When cultured on an LB agar, Arthrobacter Protophormiae colonies were small yellow and raised. When testing the susceptibility to S. aureus and E.coli with the patch plate, our organism was only susceptible to S. aureus. Arthrobacter is commonly found in soil. Arthrobacteria are nonsporulating and are a gram-positive bacteria.

Genome Structure

Our 16S ribosomal sequence we obtained from PCR and sequencing is:



This was put into a BLAST searching database and we found our results to match the closest with Arthrobacter protophormiae

Cell Structure, Metabolism and Life Cycle

Arthrobacteria are nutritionally versatile, using a variety of substrates in their oxidative metabolism including nicotine, nucleic acids, and various herbicides and pesticides. The cells are able to survive under stressful conditions induced by starvation, ionizing radiation, oxygen radicals, and toxic chemicals. A distinctive feature of this genus is that the shape of the cells change during the growth cycle, typically forming rods during early growth and cocci in the later stages. 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).

Physiology and Pathogenesis


  • Phenol Red Broth Tests: Glucose: ; Lactose: ; Sucrose:
  • Starch Hydrolysis Test:
  • Casein Hydrolysis Test:
  • Gelatin Hydrolysis Test:
  • DNA Hydrolysis Test:
  • Methyl Red Test:
  • Voges Proskauer Test:
  • Citrate Test:
  • SIM Tests:
  • Nitrate Reduction: positive
  • Urea Hydrolysis:
  • Triple Sugar Iron Agar:
  • Oxidase Test:
  • Eosin Methylene Blue Agar (EMB) Test:
  • Hektoen Enteric Agar (HE) Test:
  • MacConkey Agar Test:
  • Decarboxylation Tests: Arginine: ; Lysine: ; Orinithine:
  • Phenylalanine Deaminase Test:
  • Catalase Test:
  • Blood Agar Test:
  • Mannitol Salt Agar (MSA) Test:
  • Phenylethyl Alcohol Agar (PEA) Test:

Arthrobacter species have been isolated a few times from patients with immunodeficiencies but most strains do not appear to be pathogenic


Wauters, Georges et al. 2000. Identification of Arthrobacter oxydans, Arthrobacter luteolus sp. nov., and Arthrobacter albus sp. nov., Isolated from Human Clinical Specimens. Journal of Clinical Microbiology, 38: 2412-2415. Funke, Guido et al. 1998. Characteristics of Arthrobacter cumminsii, the Most Frequently Encountered Arthrobacter Species in Human Clinical Specimens. Journal of Clinical Microbiology, 36: 1539-1543. Funke, Guido et al. 1996. Isolation of Arthrobacter spp. from Clinical Specimens and Description of Arthrobacter cumminsii sp. nov. and Arthrobacter woluwensis sp. nov. Journal of Clinical Microbiology, 34: 2356-2363. Eschbach, Martin et al. 2003. Members of the genus Arthrobacter grow anaerobically using nitrate ammonification and fermentative processes: anaerobic adaptation of aerobic bacteria abundant in soil. FEMS Microbiology Letters, 223: 227-230.


Page authored by Melissa Brown and Samantha Limon, students of Prof. Kristine Hollingsworth at Austin Community College.