Lactic acid bacteria as biocontrol agents of soil-borne pathogens

Abstract: Lactic acid bacteria (LAB) might be a novel promising bacterial group in thebiological control of soil-borne pathogens. The potential of this bacterial group to suppresscertain fungi has been shown in the control of post-harvest diseases of fruits and vegetables, butnot much is known about their ability to protect plant roots against soil-borne pathogens. Fromsoil and the rhizosphere of maize, rye, carrots, garden soils and compost from two origins 294isolates of LAB have been obtained and tested in a confrontation assay against Pythium ultimum.In total, about 75% of the isolates showed an inhibitory effect. The most promising isolates werefurther tested in the pathosystem Pythium/tomato in pot trials. The LAB were able to protect theplants against the pathogen. Additionally the germination of tomato was significantly enhancedwhen the seeds were treated with LAB. Therefore we conclude that LAB are a promisingbacterial group for use in the biological control of soil-borne pathogens.