Construction of improved fluoroacetate degrading rumen bacteria

Summary

Genetically modified rumen bacteria were constructed to reduce loss of livestock from fluoroacetate poisoning by toxic native plants across northern and western Australia. Four strains of GM rumen bacteria were previously shown to protect sheep against fluoroacetate. In Projects TR.044 and TR.044B, five additional bacterial strains were modified, to double the total protective capability, and were tested for their ability to protect feral animals from poisoning by fluoroacetate (Compound 1080). All seven strains of Butyrivibrio fibrisolvens failed to colonise the digestive tracts of rabbits or cats after two oral inoculations of 108 bacteria. The two GM Bacteroides strains colonised cats and rabbits, but made no difference to their fluoroacetate sensitivity. Transfer of rumen bacteria between animals 30 metres apart was shown to occur in open fields, therefore preparations were made for a cattle toxicity trial to be performed in the AAHL PC2 facility.

Administrative delays prevented commencement of the trial before regulatory changes created additional time requirements and the project was terminated. The improved bacterial consortium is expected to reduce significantly the effects of fluoroacetate on sheep and cattle. After proving the safety of the bacteria for release, they are expected to reduce financial losses from poisoning of livestock.