Phytophthora infestans (Mont.) de Bary, has caused considerable losses in all areas where are cultivated the Solanaceae . Its control has been done by chemical, biological, and traditionally by farmers using sisal juice. We isolated bacteria present in the sisal juice. These were tested for antagonism to P. infestans using the principle of Bauer-Kirby technique. The isolate with most inhibition zone was submeted to fermentation in sterile sisal juice and was also tested for antagonism against P. infestans on tomato agar amended with the fermented broth. Finally, we performed the molecular characterization of isolates selected using the 16S rRNA gene ribosomal. We obtained a total of 41 isolates, eigth of which showed good growth inhibition in vitro of P. infestans . The M46 Isolate was selected for testing of antagonism in tomato agar plates amended with 200μl of fermented broth and reached a rate of 95,4% inhibition of growth of P. infestans . The M46 isolate was identified as Bacillus sp M46 with a percentage identity of 85% with Bacillus cereus . The strain of Bacillus sp. M46 has potential as a control agent for the pathogen P. infestans .