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QUESTIONS 26-27. An analysis of the efficiency of sterilization by boiling produ

ID: 39230 • Letter: Q

Question

QUESTIONS 26-27. An analysis of the efficiency of sterilization by boiling produced the graph below. From the graph, determine the decimal reduction time at 100 degree C (D100) for each species? The decimal reduction time is the time needed to kill 90% of living bacteria. Bacillus subtilis: ________ _______ 1,000,000 Bacillus stearothermophilus: 26) Which species is more heat-resistant? 27) If you started with 10,000 cells of B. stearothermophilus , how long would you need to boil the sample to be left with only one cell ? Biology Side Note: In reality, B. stearothermophilus is much more resistant to boiling than described here: its D105 is around 3000 seconds.

Explanation / Answer

Bacillus subtilis D100: 240 sec

Bacillus stearothermophilus D100: 340 sec

26. Bacillus stearothermophilus

27. 0.003 sec