Day 081 - 31 Jan 95 - Page 55
1 MR. MORRIS: Just one further question. You said that bacteria
2 multiply most rapidly at 37 degrees centigrade?
3 A. No. I said the pathogenic organisms tended to favour
4 37 degrees. That is their optimum.
5
6 Q. At what temperatures are bacteria able to multiply? At
7 what temperatures are bacteria able to multiply, the kind
8 of bacteria we have been talking about today?
9 A. Pathogenic bacteria?
10
11 Q. Yes, the ones we have referred to today.
12 A. Generally, they are destroyed at just -- I mean we are
13 talking in ----
14
15 Q. To be absolutely sure what would be definitely they cannot
16 multiply above a certain point?
17 A. You are talking about the thermal death point, and each
18 organism will have a different thermal death point. You
19 can down in temperature and they will gradually be
20 inhibited as you go down in temperature.
21
22 Q. What temperature are they actually destroyed at then?
23 A. At the thermal death point.
24
25 Q. Of each one? Say, for example, salmonella what would that
26 be?
27 A. I would have to take a guess and say something like 50
28 degrees Celsius, 55 degrees Celsius maybe.
29
30 Q. At what temperature can they not multiply, do you happen to
31 know?
32 A. The low temperature?
33
34 Q. Say, for example, I do not mean destroyed, but the ones at
35 which they cannot -----
36
37 MR. JUSTICE BELL: You are talking about low temperature there,
38 are you?
39
40 MR. MORRIS: Yes, low temperature.
41
42 MR. JUSTICE BELL: That is what I thought you were talking about
43 originally because you did ask at what temperature they
44 could not multiply, so I think we are talking about low
45 temperature.
46 A. Yes.
47
48 MR. MORRIS: Yes.
49
50 MR. JUSTICE BELL: You said something earlier about 5 degrees
51 centigrade below that they would not procreate.
52
53 MR. MORRIS: You said they were inhibited at 5 degrees.
54 A. Inhibited because they are living organisms and you are
55 talking about many millions, so I would not say it was
56 impossible for them to multiply at very low temperatures,
57 but generally it is accepted that below 5 degrees Celsius
58 there is minimal multiplication.
59
60 Q. So there would be some multiplication but not substantial?
