Association for Biology Laboratory Education

Identification of Bacterial Species
 

Kimberley Christopher and Elsa Bruno

Tested Studies in Laboratory Teaching, 2003, Volume 24

Abstract

Students are introduced to the streaking technique to isolate colonies from a mixed liquid bacteria culture and to several standard microbiological identification tests. The morphology of isolated colonies and the morphology and Gram stain reaction of the cells of each colony are examined. Each cell type is examined for the ability to use glucose as a carbon source, ability to form endospores, oxygen requirements for growth, and motility using prepared micrographs. Students compare the characteristics of the cells of the mixed bacterial culture with the same set of characteristics of six bacterial species of known identity, in an attempt at an initial identification of the bacteria of the mixed culture.

Keywords:  morphology, Gram stain, cell morphology, colony morphology, carbon use, oxygen use, motility, endospore formation

Louisiana State University (2002)