Dados do Trabalho

Título

INHIBITORY EFFECTS OF FERMENTED FRUIT BYPRODUCT EXTRACTS ON DIFFERENT Colletotrichum SPECIES

Introdução

Anthracnose is a fungal disease affecting tropical fruits and causing great economic losses to the fruit production chain. Synthetic fungicide is still the primary strategy applied to control anthracnose in fruits, but it has adverse effects on health and the environment. This study evaluated the effects of different concentrations of fruit by-product extracts fermented with lactic acid bacteria (LAB) to control different Colletotrichum species causing anthracnose.

Material e Métodos

The fermentation was developed in a 1:5 ratio of acerola, cashew, and mango lyophilized by-products in sterilized distilled water inoculated with a mixed LAB culture (Levilactobacillus brevis 59, Lactiplantibacillus pentosus 129, and Limosilactobacillus fermentum 263) at approximately 9 log CFU/mL. Fermentation was conducted at 37 ºC for 24 h in an orbital shaker (200 rpm) under aerobiosis. Fermented fruit by-products were mixed with 70% ethanol (1:5 v/v) and homogenized at 30 °C, 200 rpm for two h. These solutions were centrifuged, the liquid part was recovered, and the solvent was removed with a rotary evaporator. The extracts obtained were incorporated in potato dextrose agar in concentrations of 50, 75, and 100 mg/mL to evaluate the effects on mycelial growth of different target Colletotrichum species. The results were expressed as % of mycelial growth inhibition (MGI%, average ± standard deviation). Statistical analyses (descriptive and inferential) were performed with SigmaStat 4.0.

Resultados e Discussão

After five days of incubation at 25 °C, all tested extract concentrations reduced the mycelial growth of the target Colletotrichum species, with %MGI values ranging from 12.39 to 54.35% toward C. tropicale CMM 4071; 7.74 to 53.55% toward C. siamense (CMM 4077); 5.00 to 82.75% toward C. gloeosporioides (CMM 320); 13.66 to 50.19% toward C. karstii CMM 4101; 9.12 to 19.18% toward C. fructicola (LM 680); and 10.89 to 45.71% toward C. chrysophilum (LM 685).

Conclusão

Antifungal activity of the fermented extracts may be attributed to metabolites, such as phenolic acids and organic acids released during the LAB fermentation. The 75 or 100 mg/mL concentrations of the fermented mango and acerola showed the strongest antifungal effects against Colletotrichum species and could be applied in alternative technologies to the management of postharvest anthracnose in fruits.