Bergey\'s Manual Exercise (Handout) (Complete BEFORE the Assignment) 1. For each

ID: 141083 • Letter: B

Question

Bergey's Manual Exercise (Handout) (Complete BEFORE the Assignment) 1. For each method of identifying microorganisms describe a strength and a weakness for the use of that method: Strength Weakness 1. Morphological methods (Simple stains, colony morphology, etc.) 2. Differential Staining (Gram, endospore, acid fast) 3. Blochemical tests (Enzyme/metabolic assays) Morphological Unknowns 1. What characteristics of a bacterium should you obtain from a gram stain? What two morphological characteristics should you ALWAYS use on a dichotomous key to help identify an unknown organism? 2. Give the morphological characteristics you should NEVER use on a dichotomous key?

Explanation / Answer

Morphological

methods

conventional and primerely used

Simple and cost effective

Can not identify bacteria

at species level and not usefull

for medical diagnosis.

Differential

staining

Gives quick results yet simple and

cost effective

Significant limitation for

environmental microbiology.

Morphological methods: microorganisms are classified on the basis of cell structure,cellular metabolism or on differences in cell compounts.

1) Characteristics obtained from gram stain:

2)Two morphological charcteristics should be used in dichotomous key:

Dichotomous means branching in to two.It is used to classify organism into two parts.

3)Two characteristics should never use in dichotomous key:

sterngth weakness