SECTION A (40 MARKS)
QUESTION 1 (20)
1.1 Differentiate between continuous culture and batch culture.
(2)
1.2 Describe the significance of antibiotic susceptibility testing.
{3)
1.3 Following the breakdown of glucose to give pyruvate, pyruvate is further metabolised
to give various products. Briefly outline the fate of pyruvate in respiration.
{6)
1.4 Microorganisms are able to carry out fermentation depending on their metabolic
pathways. Briefly evaluate three different types of fermentation common in
microorganisms.
{9)
QUESTION 2 {20)
2.1 Jane is fourth year B.Sc. Honours student and she did an experiment to analyse the
microbial load of water samples using the Most Probable Number {MPN) method in
her laboratory. Jane used the MPN table (illustrated in table 1) and got an MPN of 9.2
per 100 ml.
Table 1: Table of the most Probable Number (MPN) per 100ml of sampling using three
tubes of each dilution
Number of positive tubes in dilutions
10ml
1ml
0.1 ml
MPN per 100
ml
A
0
0
0
B
0
1
0
3
C
0
0
3
6
D
0
1
0
3
E
0
1
1
6.1
X
0
1
--
2
--
9.2
..
-
-
G
0
1
3
12
2.1.1 Briefly describe the principle and procedure of MPN that she used to arrive at an MPN
of the row labelled X in the table.
(7)
2