ACTIVITY 2:DETERMINATION OF MICROBIAL MOTILITY

Amarillo, Rachelle LouieseBade, Angelica MaeVictoria, Celine

INTRODUCTIONMany but not all bacteria exhibit motilityFlagella, Cilia, Pseudopods (Eukaryotic Cells)

Gliding Motility, Spirochaetal Movement (Prokaryotic Cells)

INTRODUCTIONImportance of Bacterial Motility Chemotactic behavior and survivalAbility to change direction (moving away or towards repellants or attractants), avoids unfavorable conditions of habitat and choose favorable environment

PathogenesisFor attachment and colonization of cell wall of host cell

MicrobiologyNutrition, Water Expulsion

INTRODUCTION Types of Bacterial Motility 1. Brownian Motion – movement exhibited by particles suspended in liquids due to the bombardment of water molecules example: Saccharomyces cerevisiae, Staphylococcus aureus 2. True Motility – independent movement brought by different mechanisms of self propulsion example: Pond water microorganism, E. coli

https://upload.wikimedia.org/wikipedia/commons/thumb/1/15/Flagellum_base_diagram_en.svg/1148px-Flagellum_base_diagram_en.svg.png

https://en.wikipedia.org/wiki/File:Brownian_motion_large.gif

INTRODUCTIONBacterial Motility TestA. Non-Pathogenic1. Wet mount – simplest way to determine

motility2. Hanging drop Method – useful in observing

the general shape of living bacteria and the arrangement of bacterial cells when they associate together

INTRODUCTIONBacterial Motility Test (cont.)B. PathogenicSoft Agar Stabbing (Culture Method)•Negative result – growth in distinct zone directly along the stab•Positive result – indicated by diffuse or cloudy growth mostly at the top or bottom of the stab

OBJECTIVES 1. Observe the motility of the microorganisms using different techniques 2. Recognize Brownian motion from true motility (self – propulsion) based on the movement of particles 3. Identify the observed microorganisms whether they are motile or non- motile 4. Differentiate the movement of microorganisms under wet mount from hanging drop technique

MATERIALS • Binocular Compound Microscope• Alcohol lamp• Cultures of

Proteus vulgarisStaphylococcus aureusMicrococcus luteusSaccharomyces

cerevisiae• Pond water

• Glass slides• Petroleum jelly• Applicator sticks• Cover slips• Inoculating loop/ needle•Disinfectant• Motility Medium

PROCEDURE A. Wet Mount Preparations 1. 1. Place small drop of pond water on a clean slide using

inoculating loop. Cover with cover slip.2. 2. Observe under HPO. * repeat steps using Saccharomyces cerevisiae B. Hanging Drop Preparation1. 1. Place four small drops of petroleum jelly on the edge

corner of the coverslip2. 2. Place two loopfuls of Micrococcus suspension at the

center.3. 3. Invert the coverslip and place it in the depression slide.

The drop must hang into the depression but should not touch the bottom of the depression slide.

4. 4. View under HPO.

PROCEDURE C. Culture Method (Proteus vulgaris, Staphylococcus aureus, Micrococcus luteus)1. Aseptic Technique2. Touch the bacterial suspension with the cooled

needle. Stab in the center of the motility medium.3. Aseptic Technique4. Incubate the medium at 37˚C for 48 hours.

ASCEPTIC TECHNIQUE

ASEPTIC TECHNIQUE

RESULTS AND DISCUSSION

Microorganisms in pond water

(HPO)

RESULTS AND DISCUSSION

Saccharomyces cerevisiae

(HPO)

RESULTS AND DISCUSSION What type of motion was exhibited by the microorganisms in pond water and by the Saccharomyces cerevisiae? • Microorganisms in pond water – true

motility• Saccharomyces cerevisiae – brownian

motion

RESULTS AND DISCUSSION Differentiate between Brownian motion from true motility.• Brownian Motion – the random movement

exhibited by particles suspended in liquids due to the bombardment of water molecules.

• True Motility – an independent movement brought about by different mechanisms of self-propulsion (e.g. flagella, cilia).

RESULTS AND DISCUSSION Differentiate the motility of the microorganisms observed in wet mount from hanging drop mount based on the rate of movement.• The motility of microorganisms observed in

wet mount is slower or eventually won’t have any movement at all in comparison to the hanging drop mount, which, in this case, has an observable original movement exhibited by the microorganisms.

Wet Mount Hanging Drop MountThe rate of movement slows

down because the wet mount slide dries due to the

heat from the light of the microscope.

The rate of movement is constant because the

petroleum jelly keeps the hanging drop mount

hydrated. The microorganisms’ movement is limited

because they are pressed in between the flat surface of the slide and the cover slip.

The microorganisms can move freely because of the curvature on the slide which

provides them space to move.

RESULTS AND DISCUSSION Show the dispersion of the cultures in the tube inoculations.

Micrococcus luteus

Proteus vulgaris

Staphyloccocusaureus

RESULTS AND DISCUSSION Motility of the Examined Organisms

Microorganisms MotilityProteus vulgaris +

Staphylococcus aureus -Saccharomyces

cerevisiae -

Micrococcus luteus -

OBJECTIVES✅1. Observe the motility of the microorganisms using different techniques✅2. Recognize Brownian motion from true motility (self – propulsion) based on the movement of particles✅3. Identify the observed microorganisms whether they are motile or non- motile✅4. Differentiate the movement of microorganisms under wet mount from hanging drop technique

REFERENCES•https://en.wikipedia.org/wiki/Brownian_motion•http://www.cellsalive.com/animabug.htm•http://www.microbehunter.com/making-a-wet-mount-microscope-slide/