Endospore Stain PDF

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Summary

Learning the correct method to stain endospore. We also learn about function of endospore, and to know what presence of endospore can tell us about bacteria health....

Description

ENDOSPORE STAIN Purpose: WHAT IS THE AIM OF TODAY’S LAB? Learning the correct method to stain endospore. We also learn about function of endospore, and to know what presence of endospore can tell us about bacteria health. Materials:

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Malachite green Safranin 2-day old slant of Bacillus megaterium or Bacillus subtilis 5-day old slant of B. megaterium or B. subtilis

Methods: (Write down what you did, step by step) Refer to pages 36-37 in the BIOL302 Lab manual. The lab was conducted by the instructor and result was given Results: (Any graphs? Screen shot/cropped data? Etc

Figure legend: (Briefly and concisely explain what data I am looking at) The pictures above show 2 cultures with different ages. The one on the top left 2 days old and the one on the right is 10 days old. The bottom pictures shows the magnified version of endospore. On the bottom left we see bacteria cell and on the bottom right we see bacteria cell and blue dots. Discussion: (Interpret what you see, why is it important, and why it look that way. Any improvements? Future direction?

The top picture to the left shows the 2 days old culture which still have enough nutrition to provide bacteria with growth and also have lower amount of bacteria waste material, which is why many bacteria are visible in that sample. The one on the right is 10 days old, and since it has less nutrition and more toxins, it resulted in a harder environment for bacteria grow and thus less bacteria are visible. On the lower right, we can see formation of many endospore, in comparison to the left sample. The sample on the right is old and in starvation, so it makes sense to produce many endospore, since there are a bacterial mechanism to combat starvation and survive for a longer time. Questions: (Answer all questions found from your lab manual section)

1. How do your two samples look different from one another? Are your results what you expected? Besides the age of the bacteria, the other difference was endospore production. It was expected to see endospore production in the 10 days old sample as it was starving and the endospore function is to enable bacteria to survive under starving conditions.

2. Based on your results, sketch what you would expect if you performed this stain with bacteria from (a) a 1-day old slant and (b) a 10-day old slant. Day 1

day 10

endospore bacteria cell 3. Suppose you took a loopful of cells from the 5-day old slant and transferred them to a fresh slant. If you performed the endospore stain with cells that had grown on the fresh slant for 1 day, what would you expect to observe?

Since the bacteria are taken from their old plates, provided with fresh resources and away from toxic wastes, I would expect to not see any new endospore production, since these bacteria are not starving anymore....