Fungicidal and anti-aflatoxigenic effects of the essential oil of Cymbopogon citratus (DC.) Stapf. (lemongrass) against Aspergillus flavus Link. isolated from stored rice

Abstract

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 0AE6 and 1AE0 mg ml )1 , respectively. Aflatoxin production was completely inhibited at 0AE1 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 2AE80 and 3AE46 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.

Combined efficacy of thymol and silver nanoparticles against Staphylococcus aureus

“…An alternative hope resides in medicinal plants, since nature is the only resource to offer an assortment of chemical compounds that can be utilized for new drug discovery. Moreover, phytohemicals are privileged with their lower mammalian toxicity, lesser environmental effects and wider public acceptance (Paranagama et al, 2003). The array of phytochemicals that have been studied for their antimicrobial activity ranges from phenolic compounds, alkaloids, saponins, glucosinates to terpenoids.…”

Potential Roles of Essential Oils on Controlling Plant Pathogenic Bacteria Xanthomonas Species: A Review

“…This growing interest is emphasized by the fact that diseases caused by plant pathogenic bacteria of Xanthomonas species are still a major problem in the world, even in well developed countries (McManus et al, 2002). In such context, plant essential oils are well known to exhibit a wide range of biological activities as well as they tend to have low mammalian toxicity, less environmental detrimental effects and wide public acceptance (Paranagama et al, 2003). Hence, they form the basis of many applications in food and agriculture industries to control plant pathogenic bacteria of Xanthomonas species.…”

In Vitro and In Vivo Effects of Aqueous Extract of Rosmarinus officinalis L. (Rosemary) in The Control of Late Blight Disease of Potato Caused by Phytophthora Infestans Mont. De Bary. in Algeria

“…Four concentrations: 5%, 10%, 20% and 100% of R. officinalis aqueous extract were treatments used for this study, and correspond respectively to treatments D1, D2, D3 and D4.Mycelial growth inhibition was based on direct contact method, described by Mishra and Dubey [7].The microbiological procedures and the minimum inhibitory concentration (MIC) of the aqueous extract were determined according to Paranagama et al [8] method For each treatment, 5 ml of plant extract was poured into Petri dishes of the same diameter (90 mm) using micropipettes. The Pea-agar medium was maintained in surfusion (45°C) then poured into Petri dishes containing aqueous extract.…”

“…The CIL was determined from the smallest concentration for which no mycelial growth and no resumption of the explant was observed on the PPA medium in the term of 7 days of incubation [8].…”