Browsing by Author "Surendra Kumar Gond"

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Antibacterial and antioxidant potentials, detection of host origin compounds, and metabolic profiling of endophytic Bacillus spp. isolated from Rauvolfia serpentina (L.) Benth. ex Kurz
(Nature Research, 2025) Rusi Lata; Surendra Kumar Gond
The research highlights the importance of exploring endophytic microbiomes of medicinal plants to uncover their potential for secondary metabolite production and their role in the biosynthesis of host-derived compounds. This study was aimed to isolate leaf endophytic bacteria of Rauvolfia serpentina, investigate their antibacterial, antioxidant potentials and detect host-origin compound reserpine using Reverse Phase High-Performance Liquid Chromatography (RPHPLC). Untargeted analysis via Ultra High-Performance Liquid Chromatography-High-Resolution Mass Spectrometry (UHPLC-HRMS/MS) was conducted for profiling main phytochemicals in the leaves and to explore potential bioactive compounds in bacterial extracts. Nine bacterial isolates were obtained from R. serpentina leaves. These isolates exhibited positive results in various biochemical tests including indole production, methyl red, Voges-Proskauer, citrate utilization, catalase and oxidase production, nitrate reduction, oxidative fermentation, and citrate reduction tests. Endophytic isolates RSLB3 and RSLB18 exhibited most potential antibacterial activity against tested human pathogenic bacteria and were identified as Bacillus sp. The extract of RSLB3 and RSLB18 also showed significant antioxidant activity compared to leaf extract. The total phenol content was similar in both these isolates while flavonoids content and DPPH scavenging activity was higher in isolate RSLB3. RPHPLC analysis confirmed the presence of reserpine in bacterial metabolites when compared to a standard reference. UHPLC-HRMS profiling unveiled a diverse range of host-derived compounds and reaction intermediates with known and unknown bioactive properties in leaf extract, RSLB3, and RSLB18. To our knowledge, this is the first study to achieve a comprehensive profiling. © The Author(s) 2025.
Bacillus siamensis CNE6- a multifaceted plant growth promoting endophyte of Cicer arietinum L. having broad spectrum antifungal activities and host colonizing potential
(Elsevier GmbH, 2021) Pralay Shankar Gorai; Ranjan Ghosh; Subhrangshu Mandal; Suvranil Ghosh; Sumit Chatterjee; Surendra Kumar Gond; Narayan Chandra Mandal
Exploration of endophytic bacteria with multiple plant growth promoting (PGP) attributes is considered as an eco-friendly and cost-effective alternative to agricultural chemicals for increasing crop productivity. In the present endeavor, healthy chickpea plants (Cicer arietinum L.) collected from district Birbhum, West Bengal, India were subjected for the isolation of endophytic bacteria having multifarious PGP properties. One potent endophytic Gram positive bacterial strain CNE6 was isolated from the nodule of chickpea and was identified as Bacillus siamensis based on 16S rDNA sequence homologies. The isolate showed a number of PGP properties like phosphate solubilization, IAA production, nitrogen fixation, hydroxamate type of siderophore production and ACC deaminase activities. The isolate CNE6 produced 33.27 ± 2.16 μg/mL of IAA in the presence of tryptophan. Production of IAA was also confirmed by HPLC analysis and it was found effective for inducing lateral root branching in chickpea. In addition, the isolate displayed significant antagonistic activity against a number of plant pathogenic fungi when tested by dual culture overlay and agar well diffusion assay. 50 % cell free supernatant of CNE6 was found effective for 60–80 % inhibition of radial growth of pathogenic fungi tested. Scanning electron microscopic observation revealed massive degradation of pathogenic fungal mycelia by the antifungal metabolites of CNE6. LC–MS analysis of bacterial lipopeptides suggested the production of antifungal antibiotics like surfactin, fengycin and iturin by the isolate. The presence of genes encoding antifungal lipopeptides was also confirmed by PCR amplification using specific primers. Green fluorescent protein (GFP) tagging of CNE6 using broad host range plasmid vector (pDSK-GFPuv) followed by colonization study indicated very good host colonization potential of the isolate and its probable movement through xylem vessels. Enhanced shoot and root length and chlorophyll content upon treatment with CNE6 as observed in in vivo pot experiments also supported the positive role of the endophytic isolate on overall development and growth of the chickpea plants. This is the first report of Bacillus siamensis as an endophyte of Cicer arietinum L. which can be successfully applied for improving the productivity of this crop plant. © 2021 Elsevier GmbH
Deciphering the Role of Reshaped Fungal Microbiome in Cadmium Accumulation in Rice Grains
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Weijun Gong; Minghui Chen; Yibin Lai; Dian Yang; Marcos A. Soares; Surendra Kumar Gond; Haiyan Li
Rice cadmium (Cd) contamination is a serious threat to global food security and human health. Plant-associated microbiomes are known to affect Cd accumulation in plants. However, the response of the rice microbiome to Cd contamination and its role in modulating grain Cd accumulation remain poorly understood. In the present study, the responses of the rhizospheric fungi (RF) community and seed endophytic fungi (SEF) community to the soil physiochemical properties of rice from moderately (MC) and severely (SC1 and SC2) Cd-contaminated paddies were investigated. Moreover, the effects of soil physiochemical properties, RF community and SEF community on grain Cd accumulation were analyzed through correlation analysis. The results showed that the Cd concentration in rice grains from SC2 exceeded the food safety standard of China and was higher than that of SC1 and MC. The Cd concentration in rice grains was positively correlated with the soil-available Cd concentration, while being negatively correlated with the available nutrient elements and pH value of soil. In addition, it was found that the diversity of RF increased with the soil-available Cd concentration, while the diversity and richness of SEF decreased with the soil-available Cd concentration. Moreover, the RF community was influenced by soil physiochemical properties. The Spearman correlation analysis showed that the soil-available Cd was positively correlated with RF Sebacina, Clonostachys, Acremonium, Talaromyces and Fusarium, and most of them were related to grain Cd concentration, while unclassified SEF Pleosporales and Xylariales were associated with grain Cd concentration. These results suggested that Cd stress triggered a niche-specific response of the rice fungal microbiome. The fungi related to soil Cd availability and rice grain Cd accumulation may have a great potential application in food safety production in Cd-contaminated soil. © 2025 by the authors.
Detection of vinblastine and related bioactive compounds from culture extracts of endophytic fungi of Catharanthus roseus
(Springer Science and Business Media B.V., 2024) Uzma Khan; Surendra Kumar Gond
This study investigates the synthesis of vinblastine by endophytic fungi isolated from leaf of C. roseus. A total of 10 endophytic fungi were selected for secretion of vinca alkaloids based on the initial screening by biochemical tests and thin-layer chromatography (TLC). Out of these ten, only four fungal extracts showed positive results for presence of vinblastine at same retention time (10 min.) compared to reference compound on HPLC analysis. The detected concentration of vinblastine was maximum (17 µg/ml) in isolate no. CRL 22 followed by CRL 52, CRL 17 and CRL 28. To validate the presence of vinblastine, ultra-high-performance liquid chromatography coupled with high-resolution accurate mass spectrometry (HRMS) was employed. This analysis confirmed the presence of anhydrovinblastine, a precursor of vinblastine through the detection of molecular ions at m/z 793.4185 in extract of CRL 17. In addition to anhydrovinblastine, the intermediate compounds essential to the biosynthetic pathway of vinblastine were also detected in the extract of CRL 17. These host-origin compounds strongly suggest the presence of a biosynthetic pathway within the endophytic fungus. Based on morphological observation and sequence analysis of the ITS region of rDNA, endophytic fungi were identified as Alternaria alternata (CRL 17), Curvularia lunata (CRL 28), Aspergillus terrus (CRL 52), and Aspergillus clavatonanicus (CRL 22). © The Author(s), under exclusive licence to Springer Nature B.V. 2024.
Exploration of oncolytic drugs from endophytic fungi of Catharanthus roseus
(Elsevier B.V., 2024) Uzma Khan; Rusi Lata; Hemant Kumar; Surendra Kumar Gond
The management and treatment of cancer and related disorders is still a challenging goal for the scientists. The current global scenario of cancer mortality is demanding to discover and develop new, safe, cost effective and potent anticancer medications. The anticancer drugs vinblastine and vincristine are solely produced by medicinal herb Catharanthus roseus. These drugs are second most widely consumed anticancer drugs after Taxol in the world; however, the plant is well recognised to produce very modest levels of these important compounds (0.0002–0.0005 %). To address this issue, the review delves into the promising alternative of using endophytic fungi which reside within the healthy plant tissues and have ability to produce host-specific bioactive compounds including vinblastine and vincristine. An endophytic fungus Talaromyces radicus is reported to produce vincristine up to 670 µg/L while Curvularia verruculosa is able to secret vinblastine at a concentration of 182 µg/L in liquid cultures respectively. Some other fungal species reported to produce either vincristine or vinblastine includes Fusarium, Alternaria, Chaetomium, Nigrospora and Eutypella. The review begins by discussing the therapeutic importance of vinblastine and vincristine, highlighting their mechanisms of action and their critical roles in chemotherapy regimens for various types of cancer. Next, the review also provides an in-depth analysis of various endophytic fungi producing vinblastine and vincristine detailing their identification, characterization, biosynthetic ability and strain improvement processes. It aims to contribute to the ongoing efforts to develop more effective and sustainable strategies for producing these critical anticancer agents, ultimately enhancing cancer treatment options and outcomes. © 2024 SAAB
Functional characterization of endophytic bacteria isolated from feather grass (Chloris virgata Sw.)
(Maximum Academic Press, 2024) Rusi Lata; Sandip Chowdhury; Surendra Kumar Gond
The objective of this research was to isolate, identify, conduct biochemical characterization, and evaluate the plant growth-promoting (PGP) characteristics of endophytic bacteria obtained from various parts of feather grass collected from waterlogged rice fields. A total of 43 bacterial isolates from roots, rhizome and leaf of Chloris virgata were isolated. They were subjected to biochemical characterization (Catalase, Oxidase, Indole, Methyl red and Vogues Prausker, oxidative fermentation test). The isolates were tested qualitatively and quantitatively for PGP traits including indole acetic acid (>0.2·µg mL−1), gibberellic acid production (> 21.03 µg·mL−1), inorganic phosphate solubilization (PSI), siderophore production (> 26.5 PSU), ammonia production (>120.0 µg·mL−1) and HCN production. The isolates were also subjected to salt (NaCl) and osmotic stress (PEG-6000). Endophytic bacteria were morphologically grouped and selected on the basis of their PGP traits for identification via 16s rRNA sequencing. The identified isolates belonged to two genera namely Bacillus and Glutamicibacter with the former being dominant in the plant. A total of 30 endophytic bacterial isolates identified by 16s rRNA gene sequencing were found to be of Bacillus spp. (25 isolates) and Glutamicibacter spp. (five isolates). © 2024 by the author(s).
Isolation and characterization of hexavalent chromium-tolerant endophytic bacteria inhabiting Solanum virginicum L. roots: A study on potential for chromium bioremediation and plant growth promotion
(Elsevier B.V., 2024) Akanksha Gupta; Surendra Kumar Gond; Virendra Kumar Mishra
Present study was performed with the aim to isolate Heavy metal Tolerant- PGPB (HMT-PGPB) from metal-contaminated site and use them for Cr bioremediation. Six different bacterial strains were obtained from the endosphere of Solanum virginicum L. roots and cultured using nutrient agar media amended with 20 mg/L of Cr(VI). The ability of these Cr(VI) tolerant bacterial isolates were assessed for PGP traits like producing siderophores, indole-3-acetic acid (IAA), and phosphate solubilization. The findings indicated that all of the isolates could produce exopolymeric substances and IAA, five of them could produce siderophores, and three could solubilize phosphate. Furthermore, the minimum inhibitory concentrations of these strains werealso determined. These strains were identified as Bacillus licheniformis SxR1, B. tequilensis SxR2, B. subtilis SxR3, B. velezensis SxR4, B. amyloliquefaciens SxR6, and B. stercoris SxR8. To validate the findings, it is crucial to comprehend how Cr(VI) affects Bacillus sp. SxR1 cells to determine the course of uptake and bacterial cell alteration, which was assessed via Fourier Transform-Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). © 2024 The Authors
Management of Black Root Disease-Causing Fungus Fusarium solani CRP1 by Endophytic Bacillus siamensis CNE6 through Its Metabolites and Activation of Plant Defense Genes
(American Society for Microbiology, 2023) Pralay Shankar Gorai; Ranjan Ghosh; Suvranil Ghosh; Smriti Samanta; Animesh Sen; Suraj Panja; Surendra Kumar Gond; Narayan Chandra Mandal
Black root rot disease of Cicer arietinum L. is accountable for substantial loss in chickpea production worldwide. Endophytic Bacillus siamensis CNE6 has previously shown multifaceted plant growth-promoting, broad-spectrum antifungal, and chickpea plant-colonizing potential. In the present study, the strain Bacillus siamensis CNE6 was used for controlling black root rot disease caused by Fusarium solani CRP1 in chickpea. CNE6 showed strong antagonistic potential against CRP1 both in vivo and in vitro. Scanning electron microscopic studies indicated cellular deformation of CRP1 due to production of b-glucanase, protease, and other secondary metabolites. A total of five compounds were detected from the cell-free supernatant (CFS) of the ethyl acetate (EA) fraction of CNE6 through gas chromatography-mass spectrometry analysis. A confocal microscopic study demonstrated strong inhibition of biofilm formation of the pathogen CRP1 by the EA fraction of CFS of CNE6. Molecular docking analysis revealed that one compound, (2E)-6-methoxy-2-[(4-methoxyphenyl)methyli-dene]-2,3-dihydro-1-benzofuran-3-one, may inhibit the activity of lanosterol 14-alpha demethylase, which is involved in ergosterol biosynthesis and beta-tubulin assembling. In vivo experiments also showed the efficacy of CNE6 for increasing chickpea growth as well as upregulation of four defense genes (CHI1, PAMP, PR2B, and TF1082) upon pathogenic challenge. Thus, our results strongly suggest a positive role for CNE6 as a prospective biocontrol agent for combating Fusarium solani in chickpea. IMPORTANCE The present work was undertaken to explore an effective biocontrol agent against the destructive black root rot disease of chickpea. We have used an efficient bacterial endophyte, CNE6, which can colonize in the chickpea root system, produce secondary metabolites and enzymes to degrade pathogenic cellular integrity, inhibit pathogenic establishment by rupturing biofilm formation, and induce host immunity upon treatment. Interaction of the bacterial metabolite was also observed with lanosterol 14-alpha demethylase, which is an important component in fungal membrane functioning. Being an endophyte, Bacillus siamensis CNE6 fulfills a suitable criterion as a biocontrol agent to control black root rot disease in chickpea and has huge prospects for use commercially. Copyright © 2023 Gorai et al.
Potential application of endophytic bacteria for induction of abiotic stress tolerance in plants
(Springer Science and Business Media B.V., 2025) Hemant Kumar; Rusi Lata; Uzma Khan; James F. White; Surendra Kumar Gond
Abiotic stress is one of the main problems in agriculture worldwide. Plants under abiotic stress suffer from a variety of morpho-anatomical, physiological, and biochemical changes that impact plant growth and development and have the possibility of significantly reducing the economic yield. Researchers have better-understood plant-microbe interactions under biotic and abiotic stress in the last several years. Endophytes are microorganisms that establish a symbiotic relationship with the host plant, exerting their presence without inducing any detrimental effects. Endophytic bacteria (EB) can regulate plant tolerance through different mechanisms, such as nutrient uptake, antioxidant enzyme activity, induction of plant development through phytohormones, and the synthesis of stress-responsive substances. Recent studies demonstrated that EB possesses the ability to elicit abiotic stress responses. EB has become a viable approach to augmenting agricultural yield and safeguarding plants against abiotic stresses. The present study provides an in-depth analysis of the significant EB contribution in facilitating plant growth and enhancing plant tolerance to abiotic stress such as drought, salinity, temperature fluctuations, heavy metal exposure, and nutrient-deficient conditions. This review addresses the role of EB in minimizing abiotic stress in plants. © The Author(s), under exclusive licence to Springer Nature B.V. 2025.
Synergistic activity of green silver nanoparticles with antibiotics
(Tehran University of Medical Sciences, 2020) Anand Kumar Keshari; Ragini Srivastava; Sudarshan Yadav; Gopal Nath; Surendra Kumar Gond
Objective(s): The present work represents the green synthesis of silver nanoparticles using Withania coagulans extract and its antibacterial property. The synergy, additive, bacteriostatic and bactericidal effect of silver nanoparticles was determined against Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Proteus vulgaris, Salmonella typhi, and Vibrio cholerae. Methods: The green silver nanoparticles were characterized by X-ray diffractometry, Transmission Electron Microscopy, Scanning Electron Microscopy and Fourier Transform Infra Red spectroscopy. The Agar dilution, Minimum Inhibitory Concentration and Bacterial Growth Inhibition methods were used for the determination of the antibacterial activity of silver nanoparticles. The Fractional Inhibitory Concentration Index method was performed to check the synergistic activity of conjugated silver nanoparticles. Results: The Withania coagulans extract were reduced the silver nitrate into silver nanoparticles which was confirmed by color changes and spectral analysis. The silver nanoparticles were crystalline, elemental and spherical. The antibacterial activity was reported in silver nanoparticles which confirmed by zone of inhibition and pores on the surface of bacteria. The conjugated silver nanoparticles with Levofloxacin have synergy and additive behavior against the tested bacteria. Furthermore, bacteriostatic and bactericidal nature of silver nanoparticles was reported in lower (<20 µg/ml) and higher concentration (>50 µg/ml) respectively. Conclusions: The phenolic compounds of W. coagulans was responsible for the formation of silver nanoparticles. The bacteriostatic and bacteriocidal activity of silver nanoparticles depends upon its concentration. The conjugation of silver nanoparticles with antibiotics may be beneficial due to its synergy and additive effect against the bacteria. © 2020 Nanomedicine Research Journal. All rights reserved.
Synthesis and Characterization of Antimicrobial Silver Nanoparticles by an Endophytic Fungus Isolated from Nyctanthes arbor-tristis
(Springer, 2020) Surendra Kumar Gond; Ashish Mishra; Satish Kumar Verma; Vijay Kumar Sharma; Ravindra Nath Kharwar
Biofabrication of metal nanoparticles is a cost-effective, one-step and ecofriendly technique. Cell filtrate of an endophytic fungus isolated from Nyctanthes arbor-tristis was challenged with 1 mM solution of AgNO3 for the silver nanoparticles (AgNPs) synthesis. A reduction of silver ions into AgNPs was observed by surface plasmon resonance at absorption maxima 422 nm. The average size of AgNPs was 35.05 nm. The maximum inhibition zones by AgNPs were 14 mm each against E. coli and Pseudomonas aeruginosa compared to AgNO3 solution used as control (10 mm and 9 mm). The fungus was identified as Phomopsis helianthi by the sequencing of ITS region of rDNA. This experiment demonstrates a single-step and ecofriendly method for biosynthesis of AgNPs and their usage as an antimicrobial agent. © 2019, The National Academy of Sciences, India.