Biotransformation of 3-hydroxy-4-(1H) pyridone by the rumen microflora from different animal sources

Mimosine, a free amino acid present in the leaves and seeds of Leucaena leucocephala, is transformed by some rumen bacteria into the goitrogenic 3-hydroxy-4-(1H) pyridone (3,4 DHP). The present study was conducted to survey the presence of 3,4 DHP-degrading microorganisms in the rumen of cattle in India, since these bacteria have previously been shown to increase the resistance of livestock to 3,4 DHP-toxicity when the plant is used as a forage crop. DHP disappearance was evaluated in semisynthetic culture media. Our results show that the ruminal fluids from experimental cattle, buffalo and goat were colonized with microorganisms that are able to metabolize DHP. However the rate of transformation was rather low, which suggests that these microorganisms do not play a significant role in detoxifying DHP in vivo.