Isolation and identification of sodium fluoroacetate degrading bacteria from caprine rumen in Brazil

The objective of this paper was to report the isolation of two fluoroacetate degrading bacteria from the rumen of goats. The animals were adult goats, males, crossbred, with rumen fistula, fed with hay, and native pasture. The rumen fluid was obtained through the rumen fistula and immediately was inoculated 100 μL in mineral medium added with 20 mmol L(-1) sodium fluoroacetate (SF), incubated at 39°C in an orbital shaker. Pseudomonas fluorescens (strain DSM 8341) was used as positive control for fluoroacetate dehalogenase activity. Two isolates were identified by 16S rRNA gene sequencing as Pigmentiphaga kullae (ECPB08) and Ancylobacter dichloromethanicus (ECPB09). These bacteria degraded sodium fluoroacetate, releasing 20 mmol L(-1) of fluoride ion after 32 hours of incubation in Brunner medium containing 20 mmol L(-1) of SF. There are no previous reports of fluoroacetate dehalogenase activity for P. kullae and A. dichloromethanicus. Control measures to prevent plant intoxication, including use of fences, herbicides, or other methods of eliminating poisonous plants, have been unsuccessful to avoid poisoning by fluoroacetate containing plants in Brazil. In this way, P. kullae and A. dichloromethanicus may be used to colonize the rumen of susceptible animals to avoid intoxication by fluoroacetate containing plants.