Microbiology Lab Report

MBK – Lab Report

Motility Testing (Lab 7)

Abstract: Objectives & Summary Statement

1. Objective: To learn flagellar structure and arrangements common in mircrobes.

a. Summary: Used a wet mount to look at the different arrangements that we could see like the monotrichous, amphitrichous,, lophotrichous, and peritrichous.

2. Objective: To use direct observation and testing to determine if a given microbe is motile.

a. Summary: We looked at direct stab in a tube to see if it was motile or not with two different samples.

MBK – Lab Report

Motility Testing

Part 1: Direct Observation of Motility

N/A

Part 2: Motility Tubes

Proteus- Cloudy rod around stabbing point, flares out-chunky around sides.

Staph Epi- Non motile stays by streak or stab point.

Questions:

A. Define the following terms:

· Monotrichous- having a single flagellum at one pole—used of bacteria.

· amphitrichous - characteristic of a microorganism that has a flagellum or flagella at each end.

· lophotrichous -a bacterial cell with two or more flagella at one or both poles.

· Peritrichous- having or being flagella which are uniformly distributed over the body.

B. What are the three commonly used techniques to test motility?

Direct observation, motility media, and flagella staining.

C. Why is semi-solid media used to test for motility?

It allows for the bacteria to move around in the medium if it is motile. If it is motile,the growth will occur throughout the tube rather than just along the line of inoculation.

D. Why might it be difficult to observe motility in your wet mount?

There are a few reasons that it could be difficult. For one, if the wet mount holds a greater percentage of immobile microbes, motile microbes could be difficult to see. The opposite holds true as well, though. Also, when using a microscope, it enlarges a very small area of the slide....