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SESSION 5: DISEASE CONTROL AND FORECASTING MODELS
P128 - Lactic acid bacteria [LAB]: potential for control
of Fusarium growth
N. Dalanaj 1,2 , F. Gaggìa 2 , L. Baffoni 2 , D. Alkadri 2 , P. Nipoti 2 , D. Di Gioia 2
1 Department of Industrial chemistry, Faculty of Natural Sciences, Tirana University. Bulevardi Zogu i
Parë,Tirana; 2 Department of Agricultural Sciences - DipSA, Bologna University, Viale Fanin 44, 40127
Bologna, Italy
E-mail: diana.digioia@unibo.it
Lactic Acid Bacteria [LAB] are worldwide known as probiotic microorganisms. One
of the most important probiotic feature is their strong activity against a wide range
of harmful bacteria/fungi (Gaggìa et al., 2011). Production of organic acids and
production of antagonistic compounds are the main mechanisms described
nowadays. This work focuses on the in vitro selection of LAB strains isolated from
environmental sources against Fusarium genus. Fusarium is a well distributed
genus of filamentous fungi affecting plant, animal and human health. In the
agricultural field, Fusarium is one of the most important plant pathogenic genera,
with a record of devastating infections in various economically important plants. In
this study, in vitro antagonistic effects of 18 isolates of Lactobacillus spp. were
evaluated against F. oxysporum f. sp. lactucae, agent of tracheofusariosis in
Lactuca sativa, F. culmorum and F. graminearum, agents of severe diseases in
cereals. Fungal inhibition was performed using spot agar test in a triplicate assay
(Magnusson et al., 2003). Overnight cultures of LAB were inoculated as spot on
MRS agar plates and allowed to grow at 30°C for 24 h. The plates were then
overlaid with 10 ml of PDA containing 10 4 mould spores/ml. After 48-72 h of
aerobic incubation at 25°C, the zone of inhibition was measured. All LAB strains
(except one) showed antifungal activity against all Fusarium species (inhibition
halo between 23.7- 65.3 mm). The highest halos were obtained against F.
graminearum on which 50% of the LAB strains showed a total growth inhibition of
the colony. These results are probably related to the high amount of organic acids
produced by LAB strains but it can also be hypothesized the presence of
antifungal compounds. In vivo application of the most successful LAB strains is
foreseen towards wheat and lettuce to confirm in vitro results.
Keywords: LAB, biocontrol, Fusarium, growth
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