Bacillus Subtilis

1799 Words 8 Pages
Biology assignment
Introduction ?
There are many bacteria present in the world that affect people on a daily basis. There are any antiseptics available on the market to help combat the war against pathogenic bacterium. A common type of bacteria includes bacillus subtillis. ?B. subtillis is a bacterium found on the skin, in the digestive tract, in epithelial wounds, on extremities of the human body, in livestock and soil. Because B.subtiliis is ubquituous, it has developed adaptive strategies to subsist in diverse environments...? (www.ncbi.nlm.nig.gov) Bacteria are classified into coccus and bacillus groups. Bacilli, such as B. Subtillis, a gram-positive, rod shaped bacterium. Gram-positive bacteria when gram-stained retain a violet colour.
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Remove the cap from the bottle containing the culture of Bacillus subtilis. Pass the neck through the Bunsen burner flame 2-3 times. Remove a few drops of culture with the sterile dropping pipette. Flame the bottle neck again and replace the cap.
Lift the lid of the Petri dishes. Place 2-5 drops of culture in the centre of the dishs. Replace the lid as quickly as possible. Discard the dropping pipette into the beaker of disinfectant.
Take the bottle of melted agar. Remove the cap and pass the neck through the Bunsen burner flame 2-3 times. Pour the contents into the Petri dishes carefully. Replace the lid as quickly as possible. Flame the neck again and replace the cap on the bottle.
Keeping the Petri dish flat on the bench, mix the agar thoroughly by gently swirling the plate as directed by your teacher. Avoid splashing the agar on to the lid or over the edge of the dish. Allow the agar to set. This is known as a pour plate.
Use a pipette and filler (or syringe) to place 9cm3 distilled water into empty bottles B and C. Using the same pipette, transfer 1cm3 antiseptic from bottle A to bottle B. Gently shake B to mix the contents, then transfer 1cm3 from B into
…show more content…
Remove the cap from the bottle containing the culture of Bacillus subtilis. Pass the neck through the Bunsen burner flame 2-3 times. Remove a few drops of culture with the sterile dropping pipette. Fame the bottle neck again and replace the cap.
Lift the lid of the first petri dish. Place 2-5 drops of culture in the centre of the dish. Replace the lid as quickly as possible. Discard the dropping pipette into the beaker of disinfectant.
Repeat the last step with the remaining 3 Petri dishes.
Take the bottle of melted agar. Remove the cap and pass the neck through the Bunsen burner flame 2-3 times. Pour the contents into each of the Petri dishes carefully. Replace the lids as quickly as possible. Flame the neck and replace the cap on the bottle.
Use a syringe to place 9cm3 distilled water into empty universal bottle D.
When the agar has set, turn the dishes upside down. Label each dish A, B, C and D. Turn the dishes the correct way up. Using flamed forceps, dip a paper disc into the Dettol. Drain the excess liquid from it, then place it on the dish labelled A. Flame the forceps and repeat the steps for Ethanol, Salicylic acid and distilled water. Replace the lids as soon as possible. Tape and label the dishes with your names and the date. DO NOT INVERT THE PLATE. It will be incubated until next

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