Antagonistic compounds from controversial bacteria with suppressing effects on the diseases caused by Phytophthora cinnamomi

This work focuses on the importance of considering the bio-substances evaluation of controversial strains against plant pathogens. The bacterial population of plant rhizosphere covers every type of plant–microbe interaction. Some of them have beneficial effects on plant growth and showed antagonistic activities against plant pathogens. The distribution of the Burkholderia genus is wide in soils, and many bacterial strains were proven to benefit and protect important crops from pathogen threats. In this study, it was possible to obtain a Burkholderia cenocepacia isolate from the rhizosphere soil of a leguminous plant. It was screened in vitro for its abilities to protect Trifolium subterraneum L. from Phytophthora cinnamomi. The current results revealed that plants enhanced the growth in plants inoculated with both, the bacterial strain and the pathogen probably because the bacteria produced antagonistic compounds such as hydrolytic enzymes. This report shows the potential ability of a rhizobacterium naturally existing in the soils to suppress the effects of the diseases caused by P. cinnamomi.