Browsing by Author "Gautam, Veer Singh"

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    Bioactive potential evaluation and purification of compounds from an endophytic fungus Diaporthe longicolla, a resident of Saraca asoca (Roxb.) Willd.
    (Springer Science and Business Media Deutschland GmbH, 2021) Nishad, Jay Hind; Singh, Arti; Gautam, Veer Singh; Kumari, Puja; Kumar, Jitendra; Yadav, Monika; Kharwar, Ravindra Nath
    An endophytic fungus (L3), isolated from the leaf tissues of Saraca asoca was identified as D. longicolla by microscopic and molecular methods. The crude extracts of D. longicolla revealed to harbor seven compounds in GC�MS analysis which was subjected to a thin layer chromatography (TLC) for purification and separation of bioactive ingredients. The partially purified fraction from TLC displayed the presence of 2-tridecene (Z) (RT-14.50), 5-tridecene (E) (RT-16.65) and 2,4-di-tert-butylphenol (RT-13.92) in GC�MS. High-performance liquid chromatography (HPLC) was performed to further purify the constituents which led to the collection of 2,4-di-tert-butyl phenol (RT-2.34) with excellent antioxidant activity and antibacterial activity against methicillin resistance Staphylococcus aureus (MRSA). � 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
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    Evaluation of Congo red dye decolorization and degradation potential of an endophyte Colletotrichum gloeosporioides isolated from Thevetia peruviana (Pers.) K. Schum.
    (Springer Science and Business Media B.V., 2023) Bharti, Rajnish; Yadav, Monika; Singh, Arti; Kumari, Puja; Nishad, Jay Hind; Gautam, Veer Singh; Kharwar, Ravindra Nath
    Decolorization and degradation of textile dye by endophytic fungi stand to be a profitable and viable alternative over conventional methods with respect to eco-friendliness, cost-effectiveness, and non-hazardous nature. One of the active fungal endophytes Colletotrichum gloeosporioides isolated from plant Thevetia peruviana (Pers.) K. Schum. was screened for laccase production and Congo red dye decolorization. Various physicochemical parameters like dye concentration, carbon sources, nitrogen sources, temperature, and pH were optimized, and the maximum decolorization (%) was achieved at 100 mg/L of dye concentration (82%), yeast extract (80%), 30 �C temp (80%), glucose (79%), and 7 pH (78%), respectively. SEM image and fungal biomass changes represent that fungus actively participated in the dye decolorization and had less significant effect on biomass. The regenerative ability of fungus C. gloeosporioides after dye decolorization indicated tolerance against the dye and was found to be more advantageous over previous reports of dye decolorization by other endophytic fungi. UV-Vis spectra, TLC, FTIR, and HPLC results confirmed the decolorization and degradation process due to absorption and biodegradation. Phytotoxicity assay depicted that degraded products are less toxic to Phaseolus mungo compared to Congo red. The overall findings showed that C. gloeosporioides possesses a good decolorization and degradation potential against Congo red and this endophyte can be profitably used for dye-containing wastewater treatment. � 2022, Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i.
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    Isolation and functional characterization of a fungal plant symbiont Nigrospora sphaerica, associated to Euphorbia hirta L.
    (Springer, 2022) Gautam, Veer Singh; Nishad, Jay Hind; Kumari, Puja; Singh, Arti; Verma, Satish Kumar; Sharma, Vijay Kumar; Kumar, Jitendra; Kharwar, Ravindra Nath
    The endophytic fungi are the endosymbiont which play important role in improving host plant fitness and source of plethora of bioactive molecules. Present study includes the assessment of antimicrobial activity, phytochemical analysis and enzymes activity of fungal endophyte EHL2, isolated from leaf tissues of an Indian medicinal plant Euphorbia hirta L. The fungus exhibited the antibacterial and antifungal activities against a broad range of bacterial and fungal pathogens. To the best of our knowledge, this is the first report about the isolation and characterization of endophytic fungus�Nigrospora sphaerica (EHL2) recovered from�E. hirta L. The minimum inhibitory concentration (MIC) of the crude extract against pathogenic bacteria ranged from 0.45 to 3.14�mg/ml. For antifungal ativity of fungus, the highest percentage of inhibition was observed against Colletotrichum sp. (33.78%) while, minimum activity was noticed against Alternaria solani (16.60%). Preliminary mycochemical analysis revealed the positive tests for alkaloids, phenolics, flavonoids and terpenoids. The results showed that the total phenolic content (TPC) and total flavonoid content (TFC) of crude extracts were 78.11 � 0.04�mg GAE/g and 235.94 � 3.06�mg RE/g, respectively. Furthermore, the fungus also produced amylase, cellulase, protease and laccase enzymes. In conclusion, these positive results of mycochemicals and enzymes activity displayed by N. sphaerica of E. hirta provide an opportunity which could be exploited for host protection against pathogens and enzyme production. � 2022, Indian Phytopathological Society.
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    Phenolic and flavonoid contents and antioxidant activity of an endophytic fungus Nigrospora sphaerica (EHL2), inhabiting the medicinal plant Euphorbia hirta (dudhi) L.
    (Springer Science and Business Media Deutschland GmbH, 2022) Gautam, Veer Singh; Singh, Arti; Kumari, Puja; Nishad, Jay Hind; Kumar, Jitendra; Yadav, Monika; Bharti, Rajnish; Prajapati, Priyanka; Kharwar, Ravindra Nath
    Since endophytic fungi are pivotal sources of various bioactive natural compounds, the present study is aimed to investigate the antioxidant compounds of the endophytic fungus Nigrospora sphaerica isolated from a pantropical weed, Euphorbia hirta L. The fungus was fermented in four different media and each filtered broth was sequentially extracted in various solvents. Crude extracts collected from different solvents were subjected to phytochemical analysis and antioxidant activity. The total phenolic content (TPC) and total flavonoid content (TFC) were maximal in ethyl acetate crude extract (EtOAcE) of endophyte fermented in potato dextrose broth (PDB) medium (77.74 � 0.046mgGAE/g and 230.59 � 2.0 mgRE/g) with the highest 96.80% antioxidant activity. However, TPC and TFC were absent in hexane extract of Czapek Dox broth (CDB) medium exhibiting the lowest 4.63 � 2.75% activity. The EtOAcE (PDB) showed a positive correlation between TFC and antiradical activity (R2 = 0.762; P < 0.05), whereas a high positive correlation was noticed between TPC and antioxidant activity (R2 = 0.989; P < 0.05). Furthermore, to determine the antioxidant activity, EtOAcE (PDB) was subjected to TLC bioautography-based partial purification, while GC/MS analysis of the partial purified extract was done to confirm the presence of phenolics along with antioxidant compounds that resulted in the detection of 2,4-Di-tert-butylphenol (13.83%), a phenolic compound accountable for the antioxidant potential. Conclusively, N. sphaerica is a potential candidate for natural antioxidant. Graphical abstract: [Figure not available: see fulltext.] � 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
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    Phytochemical analysis and antimicrobial activity of an endophytic Fusarium proliferatum (ACQR8), isolated from a folk medicinal plant Cissus quadrangularis L.
    (Elsevier B.V., 2021) Singh, Arti; Kumar, Jitendra; Sharma, Vijay Kumar; Singh, Dheeraj Kumar; Kumari, Puja; Nishad, Jay Hind; Gautam, Veer Singh; Kharwar, Ravindra Nath
    The endophytic fungi are an important source of bioactive natural products. This study includes evaluation of antimicrobial activity and phytochemical analysis of endophytic fungus ACQR8, recovered from the root tissues of a folk medicinal plant Cissus quadrangularis L., which was identified as Fusarium proliferatum by microscopic and molecular methods. The fungus showed broad spectrum antibacterial and antifungal activities against variety of important plant and human pathogens. To the best of our knowledge, this is the first study to record antifungal activity of any endophytic Fusarium sp. against phytopathogens Rhizoctonia solani, Fusarium oxysporum and the dermatophytes Trichophyton mentagrophyte and Microsporum gypseum. The minimum inhibitory concentration of the crude extract ranged from 40�120 �g/ml against pathogenic bacteria and 0.2�2.5 mg/ml against fungal pathogens. Besides, this study probably is also the first to document the phytochemical constituents of an endophytic Fusarium sp. Phytochemical testing and GC-MS (gas chromatography- mass spectrometry) analysis revealed the presence of fatty acids and its derivatives, phenolics, terpenoids and unsaturated alkenes in the crude extract which scientifically validates the highly promising antibacterial and antifungal activity exhibited by endophytic isolate ACQR8. � 2021 SAAB