In vitro Studies on Antimicrobial Activities of Lactic Acid Bacteria Isolated from Fresh Vegetables for Biocontrol of Tomato Pathogens

Abstract

Aims: This study was focused on using Lactic Acid Bacteria (LAB) isolated from fresh vegetables which has been molecularly identified for in vitro control of some tomato pathogens. Study Design: The inhibitory potentials of supernatant obtained from previously characterized LAB isolates or vegetable origin were investigated against some tomato phytopathogens using agar-well method with the view to develop biological agents for some tomato disease causing organisms. Place and Duration of Study: Biotechnology Centre of Federal University of Agriculture, Abeokuta, Ogun State, Nigeria, between January 2011 and February 2012. Methodology: The antimicrobial activities of LAB against some tomato phytopathogenic bacteria which include (Xanthomonas campestries, Erwinia caratovora, and Pseudomonas syringae) were obtained by using the agar well diffusion method. Results: The result indicates that cell free culture of LAB from fresh vegetables origin (Weissella paramesenteroides, Lactobacillus pentosus, Weissella cibaria, Pediococcus pentosaceus, Weissella kimchi and Lactobacillus plantarum) can inhibits these bacteria by creating clear zones of inhibition around the wells containing cell free supernatants of the above mentioned strains of lactic acid bacteria. Pediococcus pentosaceus showed the highest zone of inhibition against Xanthomonas campestries at 15 mm radius, Weissella kimchi was the least effective against Pseudomonas syringae at 3.67 mm and Erwinia caratovora at 3.50 mm radius. Conclusion: Tomato disease causing organisms can be most likely biologically controlled by using extracts from LAB. This finding will reduce the potential hazard from the use of chemical herbicides on plant.