|MadSci Network: Molecular Biology|
Hi Andrew, I think their most important role has been, and is, to make proteins and peptides we would have a hard time producing otherwise. Hereís an example: haemophiliacs are people who cannot stop bleeding if they get cut. To get the compound they lack in their blood one used to gather enormous amounts of blood plasma and extract the minute amounts of protein from it. Tons of plasma could be needed for a single shot of medicine. Huge plants were needed, the plasma used was obviously not available for the hospitals (who need it badly to treat people who have lost a lot of blood) and there was always a risk of the medicine getting contaminated by using plasma from sick people. This is an expensive, ineffective and potentially dangerous way of making the medicine. In come the genetically modified bacteria. You can grow them in tanks while they produce the human protein that you just extract from the tank. Now the medicine can be produced safely and cheaply in large amounts. This change in production has been made possible for many medicines. Another important example of this shift is insulin for people with diabetes. For this kind of application itís not so dangerous that the bacteria are genetically modified, as they never leave the tanks they are growing in. A second important application is to use some bacteriaís special features. Here, if they are genetically modified, one would have to be careful that they do not spread. However, many times they donít need to be modified: just by using them in a new environment, they can do a lot of good. For exemple: oil-eating bacteria that munch on oil spills, bacteria that pick out heavy metals from sewers, bacteria spread on seeds that protect the growing plant from fungus attacks, or bacteria added to food to give them special qualities ( so called smart food). There is one bacterial source for biotechnology that is maybe easily overlooked: when one harvests parts of processes that only some bacteria could do. The most impressive example is Thermofilus aquaticus that lives in very hot water. In order to do this it needs, of course, to handles all its life processes at very high temperatures. By using the enzyme it carries for duplicating DNA, a process that is now used in nearly all biochemical labs in the world was created: PCR, or Polymerase Chain Reaction! This is what allows the police to get information from a small drop of blood, or to look at the genes from a long-gone mammoth. The inventors got their Nobel Prize for their efforts in 1993. As you see, bacteria are used in many ways in biotechnology. Kind regards, Erik
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