Browsing by Author "M.S. Dkhar"

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Assessment of chemically characterised Gaultheria fragrantissima Wall. essential oil and its major component as safe plant based preservative for millets against fungal, aflatoxin contamination and lipid peroxidation during storage
(Springer India, 2018) Manoj Kumar; Parismita Sarma; M.S. Dkhar; H. Kayang; Richa Raghuwanshi; Nawal Kishore Dubey
The present study aims survey of fungi causing deterioration of millets during storage, detection of aflatoxigenic fungal strains ans assessment of chemically characterized Gaultheria fragrantissiuma Wall essential oil (EO) and its major component methyl salicylate (MS) as plant based preservative. Essential oil (EO) and its major component methyl salicylate (MS) as plant based preservative was evaluated. In this study a total of 13 fungal species along with toxigenic strain of Aspergillus flavus were isolated from the millets. Chemical characterization of G. fragrantissima EO through GC–MS analysis revealed Methyl salicylate (98.04%) as major component. The EO significantly inhibited growth and aflatoxin B1 production by toxigenic strain of A. flavus LHP (B)-7 at 1.0 and 0.7 µl ml−1 respectively. In addition, EO exhibited remarkable antioxidant activity (IC50 7.5 µl ml−1). EO and MS showed non phytotoxic nature on germination of millets. The LD50 of the EO was 3833.33 µl kg−1 for mice showing favourable safety profile. In view of side effects of synthetic preservatives, the study recommends G. fragrantissima EO as a safe plant based preservative to enhance shelf-life of food commodities during storage. © 2017, Association of Food Scientists & Technologists (India).
Chemically characterised Artemisia nilagirica (Clarke) Pamp. essential oil as a safe plant-based preservative and shelf-life enhancer of millets against fungal and aflatoxin contamination and lipid peroxidation
(Taylor and Francis Ltd., 2020) Manoj Kumar; Abhishek Kumar Dwivedy; Parismita Sarma; M.S. Dkhar; H. Kayang; Richa Raghuwanshi; Nawal Kishore Dubey
The study recommends the Artemisia nilagirica (Clarke) Pamp. essential oil (ANEO) as plant-based shelf-life enhancer of millets against fungal, aflatoxin B1 (AFB1) contamination and lipid peroxidation with favourable safety profile. Chemical characterisation of ANEO through GC-MS, recorded 1,5-heptadiene-4-one,3,3,6-trimethyl (32.72%)as the main compound, followed by Artemisia alcohol (13.40%), alpha lonone (4.55%), benzene, methyl (1-methylethyl) (2.97%) and 1-cyclohexene-1-carboxaldehyde,4-(1-methylethyenyl) (2.23%). The mycoflora analysis of millet samples showed Aspergillus flavus strain[LHP(R)-5] as the most AFB1 secreting strain. The ANEO inhibited growth and AFB1 production by the toxigenic strain at 1.4 and 1.0 µL mL−1, respectively, and also possess broad fungitoxic spectrum. The decrement in membrane ergosterol content, enhanced leakage of cellular Ca2+, K+ and Mg2+ ions along with SEM and TEM study of ANEO-treated cell denotes plasma membrane as antifungal site of action. The ANEO also showed strong antioxidant activity as determined by DPPH• and ABTS•+ assays having IC50 value 2.51 and 1.07 µL mL−1, respectively. More than 70.78% protection of Ragi samples from fungal contamination was observed during in situ trial. The ANEO showed favourable safety profile with high LD50 value (7528.10 µL kg−1) for male mice and also exhibited non-phytotoxicity for Ragi seeds germination. © 2019, © 2019 Societá Botanica Italiana.
Diversity of endophytic fungi associated with hedychium spicatum ham ex sm. And their antifungal activity against the phytopathogen alternaria solani
(MRF, 2020) Parismita Sarma; M.S. Dkhar; H. Kayang; M. Kumar; N.K. Dubey; R. Raghuwanshi
Twenty eight strains of endophytic fungi including sterile mycelia were isolated from the leaf, rhizome and roots of Hedychium spicatum Ham ex. Sm. Majority of the endophytic fungi isolated belonged to the phylum Ascomycota which accounted of about 84%. The endophytic assemblage was dominated by the class Sordariomycetes. Endophytic fungal genera such as Fusarium and Penicillium were found to be common to all the plant parts. Diversity of endophytic fungi was found to be highest in the roots (H’= 2.43). Mucor hiemalis, Penicillium sp., Penicillium expansum, P. simplicissimum, Phoma medicaginis, Trichoderma sp. and T. gamsii showed above 60% inhibition against the phytopathogen Alternaria solani. © 2020, MRF. All rights reserved.