A bacterial culture (200 l containing 1.8 109 cells) was treated with an antibiotic Z (50 g per ml) for 4 h at 37 C. After this treatment, the culture was divided into two equal aliquots. Set A : 100 l was plated on Luria agar. Set B : 100 l was centrifuged, the cell pellet washed and plated on Luria agar.After incubating these two plates for 24 h at 37 C, Set A plate showed no colonies, whereas the Set B plate showed 0.9 109 cells. This experiment showed that the antibiotic Z is

A bacterial culture (200 l containing 1.8 109 cells) was treated wi

1.	A bacterial culture (200 l containing 1.8 109 cells) was treated with an antibiotic Z (50 g per ml) for 4 h at 37 C. After this treatment, the culture was divided into two equal aliquots. Set A : 100 l was plated on Luria agar. Set B : 100 l was centrifuged, the cell pellet washed and plated on Luria agar.After incubating these two plates for 24 h at 37 C, Set A plate showed no colonies, whereas the Set B plate showed 0.9 109 cells. This experiment showed that the antibiotic Z is
A.	bacteriostatic
B.	bacteriocidal
C.	bacteriolytic
D.	apoptotic
Answer» B. bacteriocidal

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