I don't know where to find it but there was an article published in The
Carnivorous Plant Society journal called "The role of Pinguicula in
taettemaelk" Volume 14 (2), 41.
It goes like this.....
Taettemaelk or `ropy milk' is a traditional milk product produced
mainly in Scandinavia, by the addition of butterwort leaves to fresh milk.
The milk product is made in small batches, with the leftovers being used
as an inoculum for the next batch. The caesin (milk protein) is not
coagulated in the same way as in the cheese-making process (editorial
note - Blessed are the cheese makers :) ) but is broken down into smaller
sized units (Lloyd, 1942). The milk is thus made thicker and contains long
`ropy' strands.
Ropiness of milk has long been a problem in the British Dairy
Industry and is caused by bacteria from the cow or from contamination in
the dairy. A source of infection by these bacteria is though to be the
butterwort (Davis, 1955).
Experiments by Darwin (1893) in his famous book,`Insectivorous
Plants', showed that _Pinguicula vulgaris_ could cause the coagulation of
milk. The role of _Pinguicula_ in the milk product is thus unclear; does
it harbour the bacteria and viruses which can contaminate milk or are the
digestive enzymes of the plant responsible for modifying the caesin of
the milk?
In order to investigate this effect, an experiment was set up
whereby 75ml aliquots of UHT or paseurised milk were aseptically placed in
sterile flasks and samples of tissue cultured _P. esseriana_ or soil
grown _P. caudata_ were added. The flasks were incubated at room
temperature for 6 days and changes in appearance noted.
The results show that none of the UHT milk samples coagulated,
whereas all of the pasteurised milk samples (including the control)
coagulated. An investigation of the coagulated sample showed a
contaminating bacterium was present in the samples, which was found to
be a Gram negative rod.
The tissue cultures can be assumed to be sterile, because any of
the contaminating organism would rapidly outgrow the plant on the nutrient
agar medium. Thus the results show that the plant itself cannot cause the
coagulation of the milk on this scale and that the pasteurised milk
contained a contaminating organism which coagulated the milk during the
incubation time. Unfortunately, due to a lack of plant material, a
soil-grown _Pinguicula_ sample was not added to the UHT milk. The results
of this experiment are therefore not conclusive and further investigation
is called for.
Darwin, C. 1893. Insectivorous plants.
Davis, J.G. 1955. A dictionary of dairying (2nd ed). Leonard Hill Ltd,
London. pp 932-935.
Lloyd, F.E. 1942. The carnivorous plants. Chronica Botanica, Waltham,
Mass. pg 113.
Cheers
Terry
bertozzi.terry@pi.sa.gov.au