Growth Inhibition of Some Phytopathogenic Bacteria by Cell-Free Extracts from Enterococcus sp

Aims: To inhibit of bacterial growth of three important phyto-pathogenic bacteria: Erwinia carotovora, Clavibacter michiganensis sp. michiganensis and Xanthomonas axonopodis by cell-free extracts from submerged cultures of two strains of Enterococcus sp. was tested.

Study Design: A complete randomized experimental design with factorial fix was used to evaluate the efficiency of growth inhibition against the phytopathogenic bacteria.

Place and Duration of Study: Laboratory of Bioprocesses, Department of Food Science and Technology, School of Chemistry, Universidad Autonoma de Coahuila, Mexico, between December 2011 and July 2012.

Methodology: Enterococci strains were isolated from goat milk, buttermilk and whey by typical microbiological procedures and primarily identified based on biochemical tests. Strains were subsequently activated in MRS broth and cells were separated by centrifugation and filtration. Cell-free extracts were tested against plant pathogenic bacteria to determine their growth inhibition potential.

Results: Strains of Enterococcus MII-1 and MIV-2 were able to inhibit the growth of three pathogenic bacteria, demonstrating to be an attractive alternative for biological control assays.

Conclusion: The cell-free extracts of Enterococcus spp. show inhibition potential to inhibit phytopathogenic bacteria that cause diseases in horticultural crops. Further studies are needed to completely evidence the high potential of use of cell-free extracts from Enterococcus MII-1 and MIV-2.