Mika R.

asked • 09/28/20

Determine number of Bacteria

Determine the number of bacteria within a 1 kilogram package of ground beef in order to provide a quantitative risk assessment and quality measure before release to public market.

Technical Data: A 1 gram sample of the ground beef was added to 99 ml of sterile saline solution and extensively mixed to resuspend all the bacteria into the solution (final volume 100ml). One millilitre of this mixture was then added to 9 ml of saline in tube A. Then 0.1 ml from tube A was spread evenly onto a growth media plate, and then the plate was incubated for 18 hours at 37 degrees to cultivate E. coli bacteria. After 18 hours, the growth media plate had 235 colonies.

From the experimental data, calculate how many bacteria are within the original 1 kg package of ground beef (considering homogeneity and representative sampling for the experiment). Write your answer as a complete number (no scientific notation, no commas, no punctuation).

1 Expert Answer


Christian S. answered • 09/29/20

New to Wyzant

PhD in Molecular Biology Specializing in Biological Sciences

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