Science

Permanent URI for this communityhttp://repository.kln.ac.lk/handle/123456789/1

Browse

Author: search.filters.author.Nugaliyadde, L.Subject: search.filters.subject.Aspergillus flavus

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Inhibition of aspergillus flavus link and aflatoxin formation hy essential oils of cinnamomum xeylanicum (L) and cymbopogon nardus rendle
    (Postgraduate Institute of Agriculture, University of Peradeniya: Peradeniya, 2002) Jayaratna, K.H.T.; Pranagama, P.A.; Abeywickrama, K.P.; Nugaliyadde, L.
    The essential oils of Cinnamomum zeylanicum (L.) leaf and Cvmbopoeon nardus Rendle were tested for their fungistatic, fungicidal and qflatoxin suppressing efficacy against an isolate of Aspergillus flavus Link, isolated from rice. The mycelial growth and the aflatoxin formation in SMKY semi synthetic liquid medium in the presence of different concentrations of two test oils were monitored. At concentrations varying from 100 to 500 ppm of the essential oil of C. zeylanicum. the mycelial dry weight decreased from 0.49 to 0.01 g/50 ml. The percentage inhibition of the mycelial growth of A. flavus increased from 50 to 95 when treated with 1000 to 1800 ppm of C. nardus oil. The minimum lethal concentrations (MLCs) for the essential oils of C. zeylanicum leaf and C. nardus were 1000 and 4000 ppm, respectively. Aflutoxins were not present in the medium at or above the concentrations of400 and 600 ppm C zeylanicum leaf and C nardus oils, respectively
  • Thumbnail Image
    Item
    Fungicidal and anti-aflatoxigenic effects of the essential oil of Cymbopogon citratus (DC.) Stapf. (lemongrass) against Aspergillus flavus Link. isolated from stored rice
    (The Society for Applied Microbiology, 2003) Paranagama, P.A.; Abeysekera, K.H.T.; Abeywickrama, K.P.; Nugaliyadde, L.
    Aims: To develop a natural fungicide against aflatoxigenic fungi, to protect stored rice, using the essential oil of lemongrass. Methods and Results: Aspergillus flavus Link. was isolated from stored rice and identified as an aflatoxigenic strain. Lemongrass oil was tested against A. flavus and the test oil was fungistatic and fungicidal against the test pathogen at 0Æ6 and 1Æ0 mg ml)1, respectively. Aflatoxin production was completely inhibited at 0Æ1 mg ml)1. The results obtained from the thin layer chromatographic bioassay and gas chromatography indicated citral a and b as the fungicidal constituents in lemongrass oil. During the fumigant toxicity assay of lemongrass oil, the sporulation and the mycelial growth of the test pathogen were inhibited at the concentrations of 2Æ80 and 3Æ46 mg ml)1, respectively. Conclusion: Lemongrass oil could be used to manage aflatoxin formation and fungal growth of A. flavus in stored rice. Significance and Impact of the Study: Currently, fungicides are not used to control fungal pests or mycotoxin production on stored rice. Rice treated with the essential oil of lemongrass could be used to manage fungal pests as well as the insect pests in stored rice. The essential oil is chemically safe and acceptable to consumers, as synthetic chemical fungicides can cause adverse health effects to consumers.