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.

About Author

Photo of author

Sagar Aryal

Sagar Aryal is a microbiologist and a scientific blogger. He attended St. Xavier’s College, Maitighar, Kathmandu, Nepal, to complete his Master of Science in Microbiology. He worked as a Lecturer at St. Xavier’s College, Maitighar, Kathmandu, Nepal, from Feb 2015 to June 2019. After teaching microbiology for more than four years, he joined the Central Department of Microbiology, Tribhuvan University, to pursue his Ph.D. in collaboration with Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Saarbrucken, Germany. He is interested in research on actinobacteria, myxobacteria, and natural products. He has published more than 15 research articles and book chapters in international journals and well-renowned publishers.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.