In vitro Evaluation of Biocontrol Potential of Lactic Acid Bacteria Isolated from Natural Ecosystem against Plant Pathogenic Fungi

Abstract

Lactic acid bacteria (LAB) are ubiquitous, Gram-positive, fermentative bacteria, which are regarded as safe for both humans and the environment. The present study aimed to evaluate the biocontrol efficiency of LAB isolated from different natural ecosystems against fungal pathogens. A total of 30 LAB was isolated from rhizosphere soil and phyllosphere sample of Solanaceous crop viz., Brinjal, Capsicum, Chilli, Tomato, whey, and sauerkraut out of them 14, 9, 4 and 3 lactic acid bacteria (LAB) were isolated from rhizosphere soil & phyllosphere sample of Solanaceous crops, whey and Sauerkraut respectively. The biocontrol ability of LAB isolates were tested against fungal plant pathogens such as Fusarium oxysporum, Pythium aphanidermatum, Sclerotium rolfsi, Rhizoctonia solani, Alternaria sp. agar well diffusion assay and mycelial growth inhibition in liquid culture. The results indicated that the isolates LAB 4, LAB 10, LAB 22, LAB 24 and LAB 29 were prominent in inhibiting the growth of most of the pathogens. Molecular characterization of selected LAB isolates revealed that LAB 4, LAB 10, LAB 22, LAB 24 belongs to Lactobacillus plantarum and LAB 29 belong to Leuconostoc mesentroides.