Use of Bacillus subtilis Strains BK1 and BT2 in the Biocontrol of Fungi Spoilage in Plaintain (Musa paradisiaca L. Corn1 Variety)

The plantain occupies fourth place in terms of live production in Côte d'Ivoire. However, it is subject to fungal attacks during its post-harvest conservation, leading to a depreciation of its marketability leading to countless losses. The aim of this work was to evaluate the antagonistic properties of two strains of Bacillus subtilis (BK1 and BT2) against the fungi responsible for spoilage of plantain variety Corn 1 in Côte d’Ivoire. To do this, a total of 180 samples composed of healthy and spoiled bananas were used for fungal isolations, carrying out biocontrol and fruit protection tests. The results of this study showed that nine (8) fungal isolates: Aspergillus sp, Rhizopus sp, Rhizomucor sp, Colletotrichum sp, Rhizoctonia sp, Fusarium sp, Lasiodiplodia sp and Geotrichum sp were identified as responsible for the alterations of plantain. In vitro antagonism and biocontrol tests showed that the two strains of Bacillus subtilis BK1 and BT2 have inhibition capacities on all 8 fungal isolates. Thus the use of the supernatant of BK1 and BT2 allowed the reduction of alterations of plantains between 80.06±2.81% and 58.44±4.50%. The two biocontrol agents tested were able to extend the shelf life of bananas over a period of 12 days. Bacillus subtilis BK1 and BT2 could therefore be used as biocontrol agents in the fight against fungal damage to plantain in Côte d'Ivoire.