Biochemical Test of Bacteroides fragilis

Biochemical Test of Bacteroides fragilis

Basic Characteristics Properties (Bacteroides fragilis)
Capsule Positive (+ve)
Catalase Positive (+ve)
Flagella Negative (-ve)
Gelatin Hydrolysis Weakly Positive (+ve)
Gram Staining Gram-negative (-ve)
Growth in Bile (20%) Positive (+ve)
Hemolysis Negative (-ve)
Indole Variable
Motility Negative (-ve)
Nitrate Reduction Negative (-ve)
Oxidase Variable
Pigment Negative (-ve)
Shape Rod-shaped cells with rounded ends.
Spore Negative (-ve)
Thioglycolate with bile Positive (+ve)
Urease Negative (-ve)

Fermentation of

Arabinose Negative (-ve)
Cellobiose Variable
Glucose Positive(+ve)
Glycogen Positive(+ve)
Inositol Negative (-ve)
Lactose Positive(+ve)
Maltose Positive(+ve)
Mannitol Negative (-ve)
Mannose Positive(+ve)
Melibiose Weakly Positive (+ve)
Raffinose Positive(+ve)
Rhamnose Negative (-ve)
Ribose Negative (-ve)
Salicin Negative (-ve)
Starch Positive (+ve)
Sucrose Positive (+ve)
Trehalose Negative (-ve)
Xylan Negative (-ve)
Xylose Positive (+ve)

Enzymatic Reactions

Alanine arylamidase Positive (+ve)
Esculin Hydrolysis Positive (+ve)
Glutamic acid decarboxylase Positive (+ve)
Glycine arylamidase Negative (-ve)
Leucine arylamidase Positive (+ve)
Leucyl glycine arylamidase Positive (+ve)
N-Acety1- b-glucosaminidase Positive (+ve)
ONPG (β-galactosidase) Positive (+ve)


  1. Editors: Krieg, N.R., Ludwig, W., Whitman, W., Hedlund, B.P., Paster, B.J., Staley, J.T., Ward, N., Brown, D., Parte, A. (2010). Bergey’s Manual of Systematic Bacteriology. Volume 4: The Bacteroidetes, Spirochaetes, Tenericutes (Mollicutes), Acidobacteria, Fibrobacteres, Fusobacteria, Dictyoglomi, Gemmatimonadetes, Lentisphaerae, Verrucomicrobia, Chlamydiae, and Planctomycetes.
  5. microbiology/bacteroides-fragilis
  6. Draper, D. L., & Barry, A. L. (1977). Rapid identification of Bacteroides fragilis with bile and antibiotic disks. Journal of clinical microbiology5(4), 439-43.

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