The table shows the pH ranges that support the growth of different bacteria. What happens to these organisms at a pH of 3.7? Bacteria pH range Salmonella 3.6–9.5 Listeria monocytogenes 4.2–9.6 Escherichia coli 4.3–9.0 a Escherichia coli grows. Listeria monocytogenes and Salmonella do not grow. b Salmonella grows. Listeria monocytogenes and Escherichia coli do not grow. c Salmonella, Listeria monocytogenes and Escherichia coli do not grow. d Listeria monocytogenes grows. Salmonella and Escherichia coli do not grow.

Answer 1

At a pH of 3.7:

• Salmonella can grow since its pH range is from 3.6 to 9.5.
• Listeria monocytogenes cannot grow since its pH range is from 4.2 to 9.6.
• Escherichia coli cannot grow since its pH range is from 4.3 to 9.0.

Therefore, the correct answer is: b Salmonella grows. Listeria monocytogenes and Escherichia coli do not grow.