Lecture on Yeast Cultivation and Microscopy

Introduction

• Yeasts are ubiquitous
• Example: Milky appearance on plums due to microorganism growth

Transferring Yeast to Nutrient Jelly

• Roll plum on special nutrient jelly
  • Jelly contains nutrients to grow microorganisms
• Goal: Transfer microorganisms from plum to jelly

Incubation

• Place jelly with transferred microorganisms in an incubator (a heater)
• Leave for 1-2 days to encourage growth

Post-Incubation Observation

• Visible cell colonies grow on jelly
• Cells grow only where plum was rolled
• Need to check under microscope for verification

Preparing Microscope Slide

1. Light bunsen burner for microbiology work
2. Use inoculating loop to pick a small colony
3. Sterilize loop by heating until red hot; cool down before use
4. Touch where no growth to check coolness
5. Stroke surface to collect cells on loop
6. Place cells on microscope slide
7. Sterilize loop again by heating
8. Spread cells by placing a drop of water; form a thin layer
9. Pass slide through bunsen flame quickly to glue cells to glass
10. Add bright red stain to cells
11. Spread stain evenly; wash off excess

Examining Under Microscope

1. Use special oil on slide for microscope work
2. Place slide on microscope stage
3. Turn on microscope light
4. Adjust slide position for desired view
5. Use oil immersion lens for close observation
6. Adjust focus and eyepiece width
7. Observe yeast cells under microscope

Conclusion

• Yeast cells can be successfully cultured and observed using the described techniques
• Importance of sterile technique and proper staining for clear microscopy