Antagonistic activity against plant pathogenic bacteria and ability to biofilm formation of Enterococcus italicus ONU547 bacteria and their consortia with Lactobacillus plantarum

Abstract

Antagonistic properties of bacteria of E. italicus ONU547 strain and their consortia with Lactobacillus plantarum ONU12 and ONU311 against plant pathogens in vivo and their ability to form biofilm on the roots of cress plant and wheat have been studied. The bacteria of E. italicus ONU547 strain showed antagonistic activity against the plant pathogens Rhizobium radiobacter C58 and Erwinia carotovora ZM1 in vivo causing 33.3 and 24.8% of inhibition, respectively, and formed the biofilm of middle level on the plant roots. The consortia of enterococci bacteria with L. plantarum showed in most cases higher antagonistic activity and ability to biofilm formation. Bacterial consortia of all used lactic acid bacteria strains showed the highest antagonistic activity against R. radiobacter causing 77.7% of inhibition. Besides this consortium, the phytopathogen E. carotovora was inhibited preferably by the mixture of enterococci with L. plantarum ONU311 (33.3% of inhibition). It has been shown that high adhesive properties and/or competition for nutrients could be the mechanism of inhibitory activity of bacteria of E. italicus ONU547 strain against plant pathogens, whereas the antagonistic activity of their consortia with lactobacilli can be explained, in addition, by the action of organic acids.