Ban on bacterium that beats plant poison
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CTA. 1995. Ban on bacterium that beats plant poison. Spore 56. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/47034
Millions of animals die each year after eating poisonous plants. The problem is particularly severe in the arid tropics when there is a dearth of normal feed supplies, and cattle are tempted to eat shrubs and trees that they would normally avoid....
Millions of animals die each year after eating poisonous plants. The problem is particularly severe in the arid tropics when there is a dearth of normal feed supplies, and cattle are tempted to eat shrubs and trees that they would normally avoid. Farmers in Australia suffer huge livestock losses each year from the poison fluoro-acetate which occurs in some acacia species. This prompted scientists at the University of New England to find ways to protect the animals. They found a soil bacterium which is able to detoxify fluoroacetate. They transferred the appropriate gene into one strain of rumen bacteria In the laboratory it successfully broke down the poison. It has now been put into the rumen of two sheep. The modified bacteria have survived and maintained their populations for five months. They appear to break down the poison, but how effectively is still not known. Laboratory tests have shown that the bacteria can reduce a fatal dose of poison to below the lethal level within an hour. Normally it would take 12 hours for the poison to act. However, genetically altered bacteria must constitute at least 0.5% of the rumen population. To err on the safe side Dr Keith Cregg, who leads the researchers, is now genetically altering three other strains of bacteria, so that at any one time at least one strain should be up to the required numbers. But the proposed inoculation of hundreds of animals from at least 30 stations in the Northern Territory and Queensland have received a set-back. The Genetic Manipulation Advisory Council (GMAC) objected to the plan because of fears that the bacterium might spread to goats, camels and rabbits which are pests in Australia, causing them to be immune to plant toxins and encouraging their spread. Feral goats are a particular problem and before resubmitting their proposal, Gregg and his colleagues will look for any correlation between toxin-containing trees and the presence or absence of goats. Goats, camels and rabbits do not have pest status in Africa far from it. If this concept is shown to be effective in Australia, it will only be a matter of time before somebody suggests that its relevance to African conditions should be examined. Anything that will broaden the range of fodder crops available to livestock is likely to be welcomed. Dr K Gregg Institute of Biotechnology University of New England Armidale, 235l AUSTRALIA