USE OF LACTIC ACID BACTERIA IN PEANUT SEED TREATMENT

Tóm tắt

Three lactic acid bacteria (LAB) strains, Lactobacillus sp. L5, Lactobacillus sp. L3, Lactobacillus sp. L2N,
isolated from Vietnamese traditional Nem chua grew well in cabbage broth supplemented with 12 g/L
glucose and 15 g/L peptone and showed inhibitory activity ranging from 40% to 44% against Aspergillus sp.
CDP isolated from mould contaminated peanuts, while Daconil 75WP – a fungicide compounds – as a positive
control showed only 26.9%. LAB strains also displayed Indole-acetic acid (IAA) production, P-solubilization
and biofilm formation. Soaking seeds in separate cabbage based culture broth of three LAB strains
with/without heat treatment and mixed culture broths at the ratio 1:1:1 with the total bacterial count
108cfu/mL exhibited the antifungal activity of mixed cultures in both cases with or without bacterial culture
heat treatment. Soaking seeds in the same mixed bacterial cultures without heat treatment increased seed
germination and vigor index, compared to the control seeds without any treatment and those treated with
fungicide compounds. After 75 days of sowing the length and total fresh weight of LAB-treated peanut plants
increased by 22.4 % and 99.6%, higher than that of Daconil treated ones with only 15.9% and 59.7%
increment. Moreover, the fresh yield of peanut pegs increased 2.5 times, compared to those of untreated and
Daconil treated seeds. This study suggested that seed treatment with LAB is a novel technology towards
organic farming to replace fungicide used in conventional agriculture.