NURSING EXAM QUESTIONS
MICROBIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Acidic pH
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Alkaline pH
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Neutral pH
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Any of the pH
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Detailed explanation-1: -Most spoilage bacteria exist at neutral pH since germs thrive in this range, but in this case, many bacteria exist in the range of 5-8 pH and perform well there. The bacterial cell membrane can also be damaged by high acidity and high alkalinity.
Detailed explanation-2: -Lactic acid bacteria (LAB) are the best natural producers but they have the major disadvantage that their growth decreases at pH values lower than 5, but a pH value as low as 3 is desirable for purification.
Detailed explanation-3: -Most bacteria are neutrophiles and grow best at near-neutral pH (center curve). Acidophiles have optimal growth at pH values near 3 and alkaliphiles have optimal growth at pH values above 9. At the other end of the spectrum are alkaliphiles, microorganisms that grow best at pH between 8.0 and 10.5.