Effect of essential oils from Eucalyptus on the growth of aflatoxigenic species

  • E. M. Da Gloria Escola Superior de Agricultura “Luiz de Queiroz” ESALQ/USP, Av. Pádua Dias, 11, Piracicaba. SP, Brazil, CEP 13418-900. Email: emgloria@esalq.usp.br (E. M. da Gloria)
  • B. Mengai Escola Superior de Agricultura “Luiz de Queiroz” ESALQ/USP, Av. Pádua Dias, 11, Piracicaba. SP, Brazil, CEP 13418-900.
  • G. Steffen Almeida Escola Superior de Agricultura “Luiz de Queiroz” ESALQ/USP, Av. Pádua Dias, 11, Piracicaba. SP, Brazil, CEP 13418-900.
  • N. C. Cuccovia Mazzotti Escola Superior de Agricultura “Luiz de Queiroz” ESALQ/USP, Av. Pádua Dias, 11, Piracicaba. SP, Brazil, CEP 13418-900.
  • C. Tadeu dos Santos Dias Escola Superior de Agricultura “Luiz de Queiroz” ESALQ/USP, Av. Pádua Dias, 11, Piracicaba. SP, Brazil, CEP 13418-900.
  • R. Moreira e Moreira Estação Experimental de Ciências Florestais de Itatinga, Estrada do Distrito do Lobo. s/ n0, CEP: 18690-000
  • I. Gomes Viera Instituto de Pesquisas e Estudos Florestais, Avenida Pádua Dias. 11, Piracicaba. SP. Brazil, CEP: 13400-970
  • M. F. G. F. Da Silva Departamento de Química, Universidade Federal de São Carlos. São Carlos – SP, Brazil, CEP 13565-905
  • S. Cruz Silva Departamento de Química, Universidade Federal de São Carlos. São Carlos – SP, Brazil, CEP 13565-905
  • M. A. Calori Domingues Escola Superior de Agricultura “Luiz de Queiroz” ESALQ/USP, Av. Pádua Dias, 11, Piracicaba. SP, Brazil, CEP 13418-900

Abstract

In Brazil, Eucalyptus species has been cultivated as source of energy and cellulose. They represent the most important cultivated forest in the country. In production areas, the leaves from the trees decay on the soil as green fertilizer. In this study were evaluated pure and blends of essential oils from different species of eucalyptus trees grown in Brazil for antifungal activity against aflatoxigenic species Aspergillus flavus and A. parasiticus. These fungal species can grow and contaminate grains during the storage period under high r.h. conditions, with an eventual production of aflatoxins. Antifungal activity was evaluated by the radial growth measurement of the fungi inoculated on maize meal extract agar basic medium. The eucalyptus oils were evaluated in a contact assay and a fumigant assay using pure and blended oils. Six concentrations of pure and blended oils were evaluated at the following doses: 0, 2, 4, 16, 32 and 84 μL per 20 mL of fungi culture medium. Fungal inocula from conidia suspensions containing 106 spores/mL was inoculated by a needle. Glass Petri dishes were incubated for 9 days at 28°C (± 0.3°C) in the dark. Antifungal activity was observed in all pure and blended oils, in different concentrations of contact and fumigant assay, for both fungi. Eucalyptus stageiriana oil and E. stageiriana + the hybrid E. grandis x E. urophylla oils blend controlled the total fungal growth at the lowest dose (20 μL).

Keywords: Essential oil; Eucalyptus spp.; Aspergillus flavus; Aspergillus parasiticus; Antifungal activity.

Veröffentlicht
2010-09-02