Browsing by Author "Veer Singh Gautam"

Now showing 1 - 9 of 9

Advances in extraction technologies: Isolation and purification of bioactive compounds from biological materials
(Elsevier, 2020) Nishi Srivastava; Arti Singh; Puja Kumari; Jay Hind Nishad; Veer Singh Gautam; Monika Yadav; Rajnish Bharti; Dharmendra Kumar; Ravindra N. Kharwar
Natural bioactive compounds (NBCs) are receiving more popularity because of their various medicinal properties and huge exploitation in various commercial sectors such as food, chemical, and pharmaceutical industries. The extraction of NBCs begins with the selection of a suitable protocol, sample preparation, and extensive literature survey. During the extraction of NBCs from biological materials, the major concern of researchers is on minimizing the interference of unwanted compounds that may coextract with the focused compounds. Numerous extraction procedures have been introduced along with existing classical extraction methodology (conventional extraction methodology), but still, scientists are in search of the development of a standard single method for extracting NBCs from biological materials. There are several critical parameters such as understanding the nature of the plant matrix and chemistry of bioactive compounds and scientific expertise that impact efficiencies of conventional and nonconventional extraction. This chapter focuses on the mechanism of different extraction techniques, extraction instrumentation, and common problems encountered and their elimination. For efficient extraction of NBCs from biological materials, there is an urgent need for advancement in selective extraction procedures, from extraction to fractionation and subsequent purification that will speed up and scale up the isolation of purified compounds from biological materials. © 2021 Elsevier Inc.
Antioxidant and cytotoxic activity of Rutin isolated from Nigrospora sphaerica, an Euphorbia hirta based endophytic fungus
(Elsevier Ltd, 2024) Veer Singh Gautam; Puja Kumari; Pradip Kumar Jaiswara; Ajay Kumar; Ravindra Nath Kharwar
The objective of this study was to isolate and characterize rutin from the endophytic Nigrospora sphaerica of Euphorbia hirta L. The compound was isolated and purified through thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Further, it was identified as rutin (RN) using fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), and high resolution mass spectroscopy (HRMS) analyses. The estimated RN concentration in the culture filtrate of N. sphaerica was 19.54 mg/L. The calculated IC50 values of RN with respect to antioxidant potential estimated using 2, 2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), hydrogen peroxide (H2O2), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and nitric oxide (NO) approaches were 29.1, 36.5, 42.2 and 43.4 µg/mL, respectively. Besides, a combined treatment of RN and cisplatin (CP) inhibited the survival of tumor cells (HuT-78) significantly (P<0.05). Interestingly, the RN enhanced the apoptosis-inducing ability of CP considerably. In conclusion, N. sphaerica may be exploited as an alternative source of rutin for various commercial applications. © 2024 Elsevier Ltd
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) Jay Hind Nishad; Arti Singh; Veer Singh Gautam; Puja Kumari; Jitendra Kumar; Monika Yadav; Ravindra Nath Kharwar
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.
Endophytic Fungi: A Cryptic Fountainhead for Biodiversity, Functional Metabolites, Host Stress Tolerance, and Myco-mediated Nanoparticles (Nps) Synthesis
(Springer Science and Business Media B.V., 2019) Jay Hind Nishad; Arti Singh; Veer Singh Gautam; Dharmendra Kumar; Jitendra Kumar; R.N. Kharwar
The view on association of higher plants and fungi from past few decades confirms the belief that all plants foster their own endophytic fungal diversity as a host, and all plant species studied till date are found to harbor one or more endophytes. The diversity of endophytic fungi can have deep impressions on plant communities through adding fitness to their concerned host conferring tolerance against abiotic and biotic stresses. While endophytes have been outlined to biosynthesize a wide array of molecules, genome sequencing of such organisms has revealed that these have the potential to provide many more secondary metabolites than usual. Recently, various methods have been advanced to aid in the activation of cryptic biosynthetic pathways. Since the most important medicinal compound taxol (paclitaxel) has been isolated from the endophytic fungus therefore, more plant mimetic compounds may be expected from this hidden microbial source. Various enzymes (amylase, lipase, cellulase, protease, lactase, pectinases, peroxidase, catalase, and penicillinase) and toxins (aflatoxin, zearalenone, ochratoxin, citrinin, T-2 toxin, and fumonisins) may be isolated from this repertoire. Cell-free extract of many endophytic fungal isolates may also be utilized to synthesize the nanoparticles like copper (Cu), silver (Ag), platinum (Pt), and gold (Au) from respective metal salt solutions. This chapter also discusses different approaches such as co-culture of microbes, altering growth media and culture conditions, genetic as well as epigenetic strategies for obtaining the biochemical treasure hidden within these unique microbes. © 2019, Springer Nature Switzerland AG.
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) Rajnish Bharti; Monika Yadav; Arti Singh; Puja Kumari; Jay Hind Nishad; Veer Singh Gautam; Ravindra Nath Kharwar
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.
Isolation and functional characterization of a fungal plant symbiont Nigrospora sphaerica, associated to Euphorbia hirta L.
(Springer, 2022) Veer Singh Gautam; Jay Hind Nishad; Puja Kumari; Arti Singh; Satish Kumar Verma; Vijay Kumar Sharma; Jitendra Kumar; Ravindra Nath Kharwar
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.
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) Veer Singh Gautam; Arti Singh; Puja Kumari; Jay Hind Nishad; Jitendra Kumar; Monika Yadav; Rajnish Bharti; Priyanka Prajapati; Ravindra Nath Kharwar
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.
Phytochemical analysis and antimicrobial activity of an endophytic Fusarium proliferatum (ACQR8), isolated from a folk medicinal plant Cissus quadrangularis L.
(Elsevier B.V., 2021) Arti Singh; Jitendra Kumar; Vijay Kumar Sharma; Dheeraj Kumar Singh; Puja Kumari; Jay Hind Nishad; Veer Singh Gautam; Ravindra Nath Kharwar
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 µg/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
Salt tolerant fungal endophytes alleviate the growth and yield of saline-affected wheat genotype PBW-343
(Elsevier GmbH, 2024) Priyanka Prajapati; Monika Yadav; Jay Hind Nishad; Veer Singh Gautam; Ravindra Nath Kharwar
The purpose of this work was to assess how salt-tolerant wheat endophytic fungi promoted the growth of salt-sensitive wheat after inoculation. The endophytic fungal assemblages from salt-tolerant wheat genotypes (KRL-213, KRL-210 and KRL-19) and from salt-sensitive wheat genotype (PBW-343) were characterized, identified and determined for the current study. Of the fifty fungal isolates collected from both the salt-tolerant and the salt-sensitive wheat genotypes, 8 isolates recovered from salt-tolerant varieties were found to be resistant at high salt concentrations. These 8 isolates were characterized through several biochemical tests, such as plant growth promoting assay, extracellular enzymatic assay, carbohydrate utilization assay, antagonism versus plants pathogens and capacity to promote wheat seedlings (pot experiments). All tests revealed the positive results for 4 fungal strains (K13TR/150, K19TR/200, K-19TL/150 and K-19TL/200). These 4 fungi were identified as Aspergillus medius (K19TR/200), Cladosporium parahalotolerant (K13TR/150), Aspergillus versicolor (K19TL/150) and Aspergillus nishimurae (K19TL/200) through 18 S rDNA sequencing. Out of these, C. parahalotolerant and A. medius showed the synergistic effect with each other, so these 2 isolates were used in further experiments. These 2 isolates were involved in increasing the root-shoot length, proline and MDA contents. SEM and fluorescence microscopy were used to detect endophytic fungal colonization in the root of seedlings. C. parahalotolerant and A. medius heavily colonized the roots and it was noticed on the 21st day of the growth phase. These findings imply that fungal isolates have the potential to confer stress tolerance to their respective hosts and may enhance the agricultural production in the future, especially considering the changes in climate. © 2023 Elsevier GmbH