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?

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