surendra gond - Academia.edu (original) (raw)
Papers by surendra gond
Microbiome Stimulants for Crops
Microbial endophytes form a symbiotic relationship with their host. Almost all plants harbor a ni... more Microbial endophytes form a symbiotic relationship with their host. Almost all plants harbor a niche of endophytic microbes. These symbionts, while residing inside, stimulate plant growth as well as gain property to synthesize host origin compounds. A number of host secondary metabolites have been reported from endophytic microorganisms like the anticancer drugs taxol and vincristine, and antimalarial artemisinin etc. This chapter discusses the mode of endophytic transmission and their potential to promote plant growth and protect from pests. The role of endophytes inducing host metabolites production in planta and the synthesis of host compounds when free living is also discussed in detail, including biotransformation of host compounds by endophytes.
Microbial Services in Restoration Ecology
ObjectiveThe present work represents the green synthesis of silver nanoparticles using Withania c... more ObjectiveThe 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. ResultsThe Withania coagulans extract were reduced the silver nitrate into silver nanoparticles which was confirm...
Developments in Fungal Biology and Applied Mycology
Fungal endophytes are commonly considered all those highly diverse fungi that colonize internal t... more Fungal endophytes are commonly considered all those highly diverse fungi that colonize internal tissue of plants either part or complete their life without causing any negative symptoms of disease. Researches on structural and functional diversity of fungal entophytes have developed great appreciation among the scientific community because its promises plethora of advantages to host plants which most of them we are not aware and to be potential source of novel metabolites that could serve as new drugs of pharmaceutical and agricultural importance. Endophytic fungi are reported from each group of plants from thallophytes to spermatophytes (algae to angiosperms) and from aquatic to xerophytic plants. Taxonomically they are categorized into two different phylogenetic groups i.e. clavicipitaceous and non-clavicipitaceous group that may be transmitted horizontally or vertically from plant to plant. Endophytism is classical example of mutualistic symbiosis which has evolved from the balanced antagonism between microbes and host plant during the course of time. Past researches on fungal endophyte mainly focused on diversity and its secondary metabolites; many aspects of their role in plant protection against biotic and abiotic stresses are less explored. Since the majority of these groups of microbes are mysterious and their other hidden potential values are yet to be discovered which need more attention. Past fragmentary reports on role of fungal endophyte in plant protection give enough clue regarding scope and application of these microbes as tools for the improving fitness of plant in terms of quality and quantity of their productivity. The present article mostly focuses to review the status on diversity of fungal endophytes in different groups of plants, and their spatio-temporal distribution including the role in plant protection.
Seed Endophytes
Maize is one of the main cereal crops grown all over the world. The presence of microbial endophy... more Maize is one of the main cereal crops grown all over the world. The presence of microbial endophytes which reside asymptomatically inside maize seeds may influence the yield and quality of crop. The present review concentrates on underexplored endophytes, such as seed-borne bacterial and fungal endophytes. The review encompasses the role of maize seed’s endophytes in enhancing crop efficiency, the nature of vertical transmission and secondary metabolites production, their belowground function, and the aboveground response. The diversity of endophytes in maize seed is discussed in detail focusing also on methodology applied for their isolation. This review may render help for the researchers working on the improvement of crops modulated through seed endophytes.
Microorganisms
Fungal endophytes are well-established sources of biologically active natural compounds with many... more Fungal endophytes are well-established sources of biologically active natural compounds with many producing pharmacologically valuable specific plant-derived products. This review details typical plant-derived medicinal compounds of several classes, including alkaloids, coumarins, flavonoids, glycosides, lignans, phenylpropanoids, quinones, saponins, terpenoids, and xanthones that are produced by endophytic fungi. This review covers the studies carried out since the first report of taxol biosynthesis by endophytic Taxomyces andreanae in 1993 up to mid-2020. The article also highlights the prospects of endophyte-dependent biosynthesis of such plant-derived pharmacologically active compounds and the bottlenecks in the commercialization of this novel approach in the area of drug discovery. After recent updates in the field of ‘omics’ and ‘one strain many compounds’ (OSMAC) approach, fungal endophytes have emerged as strong unconventional source of such prized products.
Planta Medica
Azadirachta indica, commonly known as neem, is an evergreen tree of the tropics and sub-tropics n... more Azadirachta indica, commonly known as neem, is an evergreen tree of the tropics and sub-tropics native to the Indian subcontinent with demonstrated ethnomedicinal value and importance in agriculture as well as in the pharmaceutical industry. This ancient medicinal tree, often called the “wonder tree”, is regarded as a chemical factory of diverse and complex compounds with a plethora of structural scaffolds that is very difficult to mimic by chemical synthesis. Such multifaceted chemical diversity leads to a fantastic repertoire of functional traits, encompassing a wide variety of biological activity and unique modes of action against specific and generalist pathogens and pests. Until now, more than 400 compounds have been isolated from different parts of neem including important bioactive secondary metabolites such as azadirachtin, nimbidin, nimbin, nimbolide, gedunin, and many more. In addition to its insecticidal property, the plant is also known for antimicrobial, antimalarial, a...
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences
Biofabrication of metal nanoparticles is a cost-effective, one-step and ecofriendly technique. Ce... more 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.
Pest Management Science
Endophytes are microbes (mostly bacteria and fungi) present asymptomatically in plants. Endophyti... more Endophytes are microbes (mostly bacteria and fungi) present asymptomatically in plants. Endophytic microbes are often functional in that they may carry nutrients from the soil into plants, modulate plant development, increase stress tolerance of plants, suppress virulence in pathogens, increase disease resistance in plants, and suppress development of competitor plant species. Endophytic microbes have been shown to: (i) obtain nutrients in soils and transfer nutrients to plants in the rhizophagy cycle and other nutrient-transfer symbioses; (ii) increase plant growth and development; (iii) reduce oxidative stress of hosts; (iv) protect plants from disease; (v) deter feeding by herbivores; and (vi) suppress growth of competitor plant species. Because of the effective functions of endophytic microbes, we suggest that endophytic microbes may significantly reduce use of agrochemicals (fertilizers, fungicides, insecticides, and herbicides) in the cultivation of crop plants. The loss of endophytic microbes from crop plants during domestication and long-term cultivation could be remedied by transfer of endophytes from wild relatives of crops to crop species. Increasing atmospheric carbon dioxide levels could reduce the efficiency of the rhizophagy cycle due to repression of reactive oxygen used to extract nutrients from microbes in roots.
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences
An endophytic fungus isolated from photosynthetic root of Tinospora cordifolia Miers. was identif... more An endophytic fungus isolated from photosynthetic root of Tinospora cordifolia Miers. was identified as Pseudofusicoccum adansoniae with 100% 18S ITS rRNA partial gene sequence similarity (accession JX951181). The fungus exhibited amylase, lipase and protease activities and was also able to assimilate the galactose, glucose, fructose, lactose and maltose along with l-arginine and alanine. In addition to siderophore production, the fungus was found to be tolerant against various concentrations of NO2−, NO3− and NaCl. The maximum biomass and metabolite yield were observed at pH range 5.4–7.0, whereas yield of secondary metabolites was highest in potato dextrose broth (36.66 ± 0.33 mg/100 ml) extracted through ethyl acetate (EtOAc). Interestingly, metabolites extracted through ethyl acetate from PDB and MEB grown cultures were found to be active against all 8 human bacterial pathogens used in this study. The isolation and characterization of P. adansoniae done in this experiment are the initial steps which pave the way for purified isolation of bioactive compounds and enzymes of immense use.
Letters in applied microbiology, Jan 22, 2018
Endophytes are microorganisms including bacteria and fungi that survive within healthy plant tiss... more Endophytes are microorganisms including bacteria and fungi that survive within healthy plant tissues and promote plant growth under stress. This review focuses on the potential of endophytic microbes that induce abiotic stress tolerance in plants. How endophytes promote plant growth under stressful conditions, like drought and heat, high salinity and poor nutrient availability will be discussed. The molecular mechanisms for increasing stress tolerance in plants by endophytes include induction of plant stress genes as well as biomolecules like reactive oxygen species (ROS) scavengers. This review may help in the development of biotechnological applications of endophytic microbes in plant growth promotion and crop improvement under abiotic stress conditions. This article is protected by copyright. All rights reserved.
Frontiers in microbiology, 2017
Grape skin and turmeric extracts having the major components resveratrol and curcumin, respective... more Grape skin and turmeric extracts having the major components resveratrol and curcumin, respectively, were used for the induction of cryptic and bioactive metabolites in an endophytic fungus Colletotrichum gloeosporioides isolated from Syzygium cumini. The increase in total amount of crude compounds in grape skin and turmeric extract treated cultures was 272.48 and 174.32%, respectively, compared to the untreated control. Among six human pathogenic bacteria tested, the maximum inhibitory activity was found against Aeromonas hydrophila IMS/GN11 while no inhibitory activity was observed against Enterococcus faecalis IMS/GN7. The crude compounds derived from turmeric extract treated cultures showed the highest DPPH free radicals scavenging activity (86.46% inhibition) followed by compounds from grape skin treated cultures (11.80% inhibition) and the control cultures (1.92% inhibition). Both the treatments significantly (p ≤ 0.05) increased the antibacterial and antioxidant activities of...
Journal of Nanomaterials & Molecular Nanotechnology, 2016
Biofabrication of Antibacterial and Antioxidant Silver Nanoparticles (Agnps) by an Endophytic Fun... more Biofabrication of Antibacterial and Antioxidant Silver Nanoparticles (Agnps) by an Endophytic Fungus Pestalotia Sp. Isolated from Madhuca Longifolia Particles of metals or other materials in nanometre size are called as nanoparticles (NPs). Of ten endophytic fungi screened, seven endophytic fungi namely Alternaria alternata, Botryodiplodia sp., Pestalotia sp., Fusarium sp., Aspergillus sp. Aschersonia sp. and Phomopsis sp. were able to synthesize silver nanoparticles. Silver metal nanopartites were synthesised successfully by both mycelium as well as cell filtrate of Pestalotia sp., which was initially observed by spectrometric analysis. TEM pictures revealed the synthesis of angular shape of silver nanoparticles like trigonal, pentagonal, hexagonal, few of cuboids and some were of spherical in shape too. Most of nanoparticles (76%) were found below the size of 40 nm. FTIR spectra peaks showed the presence of -NH, CO, C=C and C-H containing organic metabolites which might play a role in stabilizing the nanoparticles. Silver nanoparticles solution (0.5 mM) inhibited the growth significantly than control against all pathogenic bacteria tested. Mycosynthesized AgNPs were most active against Aeromonas hydrophila @2 μg/ml IC50 followed by Staphylococcus aureus (6 μg/ml), Escherichia coli (8μg/ml), Morganella morganii (24 μg/ml), Salmonella typhi (42 μg/ml), Enterococcus faecalis (40 μg/ml) and Klebsiella pneumoniae (50 μg/ml) respectively. Silver nanoparticles had also shown antioxidant activity with DPPH free radical scavenging with inhibitory concentration (IC50) at 47 μg /ml. To combat with new emerging pathogenic bacteria that threat our society by causing dreadful diseases, we require the development of effective therapeutics. Thus, eco-friendly synthesised antimicrobial and antioxidant silver nanoparticles allow us to suitably employing their application in nanoparticles mediated drug delivery and therapy of diseases.
PloS one, 2016
The endophytic Streptomyces coelicolor strain AZRA 37 was isolated from the surface sterilized ro... more The endophytic Streptomyces coelicolor strain AZRA 37 was isolated from the surface sterilized root of Azadirachta indica A. Juss., commonly known as neem plant in India. Since only a few reports are available regarding epigenetic modulations of microbial entities, S. coelicolor was treated with different concentrations of 5-azacytidine for this purpose and evaluated for its antibacterial potential against five human pathogenic bacteria (Aeromonas hydrophila IMS/GN11, Enterococcus faecalis IMS/GN7, Salmonella typhi MTCC 3216, Shigella flexneri ATCC 12022 and Staphylococcus aureus ATCC 25923). The crude extract obtained from cultures treated with 25 μM concentration of 5-azacytidine, was found effective against all five pathogenic bacteria tested while the untreated control was only active against 3 pathogenic bacteria. HPLC analysis of crude compounds from treated cultures showed a greater number of compounds than that of the control. Extraction of whole cell protein and its SDS PAG...
Vegetos- An International Journal of Plant Research, 2015
Seventeen isolates of Pseudomonas fluo-rescens (Pf) were examined for growth promotion and the in... more Seventeen isolates of Pseudomonas fluo-rescens (Pf) were examined for growth promotion and the induction of systemic resistance against early blight disease of tomato. A noticeable in-crease in shoot and root length was observed in plants treated with P. fluorescens. However, the root development was reduced by a combination of P. fluorescens and Alternaria alternata (A. alter-nata). P. fluorescens isolates systemically induced resistance against early blight of tomato caused by A. alternata and reduced (approx.18–42%) the dis-ease significantly. All the isolates of P. fluorescens produced salicylic acid (SA) in King's B (KB) broth and induced its accumulation in tomato leaf within 24 h of bacterial inoculation. SA levels were signifi-cantly increased in plants treated with bacteria compared to the split control from one to five days following inoculation. Low SA concentration (0.1–0.5 mg/ml) did not inhibit mycelial growth of A. alternata in vitro, contrary to inhibition at high concentrations. The exogenously applied SA first accumulates in host tissues and induces resistance, however, endogenous SA accumulation in plant tissue is considered to be involved in induced sys-temic resistance to early blight disease of tomato caused by A. alternata.
Symbiosis, 2015
An endophytic Bacillus amyloliquefaciens subsp. subtilis was isolated from surface sterilized see... more An endophytic Bacillus amyloliquefaciens subsp. subtilis was isolated from surface sterilized seedlings of tropical corn. To evaluate the hypothesis that this endophyte is defensive in nature and determine the mechanisms of host defense we examined the effects of the endophyte on pathogens and host disease resistance genes. The bacterial endophyte showed antifungal activity against fungal pathogens Fusarium moniliforme, Colletotrichum gloeosporioides and Aspergillus flavus. Plant protection activity was also observed in Indian popcorn seedlings inoculated with the endophyte against F. moniliforme. Gene expression analysis was conducted and demonstrated that up-regulation of several defense genes in corn was greater after 48 hours of pathogen challenge than 24 hours. Plant defense pathways triggered by the endophytic bacterium appeared to be SA (salicylic acid) independent. The abundance of the zm Jasmonic acid-induced gene expression was greater in pathogen challenged plants pre-treated with the endophytic bacterium than in the plants challenged only with pathogen. Pre-treatment with the endophytic bacterium resulted in a more intense induction of maize pathogenesis related protein genes PR-1 and PR-10 during interaction with F. moniliforme compared to plants that were treated only with the fungal pathogen.
Microbiome Stimulants for Crops
Microbial endophytes form a symbiotic relationship with their host. Almost all plants harbor a ni... more Microbial endophytes form a symbiotic relationship with their host. Almost all plants harbor a niche of endophytic microbes. These symbionts, while residing inside, stimulate plant growth as well as gain property to synthesize host origin compounds. A number of host secondary metabolites have been reported from endophytic microorganisms like the anticancer drugs taxol and vincristine, and antimalarial artemisinin etc. This chapter discusses the mode of endophytic transmission and their potential to promote plant growth and protect from pests. The role of endophytes inducing host metabolites production in planta and the synthesis of host compounds when free living is also discussed in detail, including biotransformation of host compounds by endophytes.
Microbial Services in Restoration Ecology
ObjectiveThe present work represents the green synthesis of silver nanoparticles using Withania c... more ObjectiveThe 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. ResultsThe Withania coagulans extract were reduced the silver nitrate into silver nanoparticles which was confirm...
Developments in Fungal Biology and Applied Mycology
Fungal endophytes are commonly considered all those highly diverse fungi that colonize internal t... more Fungal endophytes are commonly considered all those highly diverse fungi that colonize internal tissue of plants either part or complete their life without causing any negative symptoms of disease. Researches on structural and functional diversity of fungal entophytes have developed great appreciation among the scientific community because its promises plethora of advantages to host plants which most of them we are not aware and to be potential source of novel metabolites that could serve as new drugs of pharmaceutical and agricultural importance. Endophytic fungi are reported from each group of plants from thallophytes to spermatophytes (algae to angiosperms) and from aquatic to xerophytic plants. Taxonomically they are categorized into two different phylogenetic groups i.e. clavicipitaceous and non-clavicipitaceous group that may be transmitted horizontally or vertically from plant to plant. Endophytism is classical example of mutualistic symbiosis which has evolved from the balanced antagonism between microbes and host plant during the course of time. Past researches on fungal endophyte mainly focused on diversity and its secondary metabolites; many aspects of their role in plant protection against biotic and abiotic stresses are less explored. Since the majority of these groups of microbes are mysterious and their other hidden potential values are yet to be discovered which need more attention. Past fragmentary reports on role of fungal endophyte in plant protection give enough clue regarding scope and application of these microbes as tools for the improving fitness of plant in terms of quality and quantity of their productivity. The present article mostly focuses to review the status on diversity of fungal endophytes in different groups of plants, and their spatio-temporal distribution including the role in plant protection.
Seed Endophytes
Maize is one of the main cereal crops grown all over the world. The presence of microbial endophy... more Maize is one of the main cereal crops grown all over the world. The presence of microbial endophytes which reside asymptomatically inside maize seeds may influence the yield and quality of crop. The present review concentrates on underexplored endophytes, such as seed-borne bacterial and fungal endophytes. The review encompasses the role of maize seed’s endophytes in enhancing crop efficiency, the nature of vertical transmission and secondary metabolites production, their belowground function, and the aboveground response. The diversity of endophytes in maize seed is discussed in detail focusing also on methodology applied for their isolation. This review may render help for the researchers working on the improvement of crops modulated through seed endophytes.
Microorganisms
Fungal endophytes are well-established sources of biologically active natural compounds with many... more Fungal endophytes are well-established sources of biologically active natural compounds with many producing pharmacologically valuable specific plant-derived products. This review details typical plant-derived medicinal compounds of several classes, including alkaloids, coumarins, flavonoids, glycosides, lignans, phenylpropanoids, quinones, saponins, terpenoids, and xanthones that are produced by endophytic fungi. This review covers the studies carried out since the first report of taxol biosynthesis by endophytic Taxomyces andreanae in 1993 up to mid-2020. The article also highlights the prospects of endophyte-dependent biosynthesis of such plant-derived pharmacologically active compounds and the bottlenecks in the commercialization of this novel approach in the area of drug discovery. After recent updates in the field of ‘omics’ and ‘one strain many compounds’ (OSMAC) approach, fungal endophytes have emerged as strong unconventional source of such prized products.
Planta Medica
Azadirachta indica, commonly known as neem, is an evergreen tree of the tropics and sub-tropics n... more Azadirachta indica, commonly known as neem, is an evergreen tree of the tropics and sub-tropics native to the Indian subcontinent with demonstrated ethnomedicinal value and importance in agriculture as well as in the pharmaceutical industry. This ancient medicinal tree, often called the “wonder tree”, is regarded as a chemical factory of diverse and complex compounds with a plethora of structural scaffolds that is very difficult to mimic by chemical synthesis. Such multifaceted chemical diversity leads to a fantastic repertoire of functional traits, encompassing a wide variety of biological activity and unique modes of action against specific and generalist pathogens and pests. Until now, more than 400 compounds have been isolated from different parts of neem including important bioactive secondary metabolites such as azadirachtin, nimbidin, nimbin, nimbolide, gedunin, and many more. In addition to its insecticidal property, the plant is also known for antimicrobial, antimalarial, a...
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences
Biofabrication of metal nanoparticles is a cost-effective, one-step and ecofriendly technique. Ce... more 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.
Pest Management Science
Endophytes are microbes (mostly bacteria and fungi) present asymptomatically in plants. Endophyti... more Endophytes are microbes (mostly bacteria and fungi) present asymptomatically in plants. Endophytic microbes are often functional in that they may carry nutrients from the soil into plants, modulate plant development, increase stress tolerance of plants, suppress virulence in pathogens, increase disease resistance in plants, and suppress development of competitor plant species. Endophytic microbes have been shown to: (i) obtain nutrients in soils and transfer nutrients to plants in the rhizophagy cycle and other nutrient-transfer symbioses; (ii) increase plant growth and development; (iii) reduce oxidative stress of hosts; (iv) protect plants from disease; (v) deter feeding by herbivores; and (vi) suppress growth of competitor plant species. Because of the effective functions of endophytic microbes, we suggest that endophytic microbes may significantly reduce use of agrochemicals (fertilizers, fungicides, insecticides, and herbicides) in the cultivation of crop plants. The loss of endophytic microbes from crop plants during domestication and long-term cultivation could be remedied by transfer of endophytes from wild relatives of crops to crop species. Increasing atmospheric carbon dioxide levels could reduce the efficiency of the rhizophagy cycle due to repression of reactive oxygen used to extract nutrients from microbes in roots.
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences
An endophytic fungus isolated from photosynthetic root of Tinospora cordifolia Miers. was identif... more An endophytic fungus isolated from photosynthetic root of Tinospora cordifolia Miers. was identified as Pseudofusicoccum adansoniae with 100% 18S ITS rRNA partial gene sequence similarity (accession JX951181). The fungus exhibited amylase, lipase and protease activities and was also able to assimilate the galactose, glucose, fructose, lactose and maltose along with l-arginine and alanine. In addition to siderophore production, the fungus was found to be tolerant against various concentrations of NO2−, NO3− and NaCl. The maximum biomass and metabolite yield were observed at pH range 5.4–7.0, whereas yield of secondary metabolites was highest in potato dextrose broth (36.66 ± 0.33 mg/100 ml) extracted through ethyl acetate (EtOAc). Interestingly, metabolites extracted through ethyl acetate from PDB and MEB grown cultures were found to be active against all 8 human bacterial pathogens used in this study. The isolation and characterization of P. adansoniae done in this experiment are the initial steps which pave the way for purified isolation of bioactive compounds and enzymes of immense use.
Letters in applied microbiology, Jan 22, 2018
Endophytes are microorganisms including bacteria and fungi that survive within healthy plant tiss... more Endophytes are microorganisms including bacteria and fungi that survive within healthy plant tissues and promote plant growth under stress. This review focuses on the potential of endophytic microbes that induce abiotic stress tolerance in plants. How endophytes promote plant growth under stressful conditions, like drought and heat, high salinity and poor nutrient availability will be discussed. The molecular mechanisms for increasing stress tolerance in plants by endophytes include induction of plant stress genes as well as biomolecules like reactive oxygen species (ROS) scavengers. This review may help in the development of biotechnological applications of endophytic microbes in plant growth promotion and crop improvement under abiotic stress conditions. This article is protected by copyright. All rights reserved.
Frontiers in microbiology, 2017
Grape skin and turmeric extracts having the major components resveratrol and curcumin, respective... more Grape skin and turmeric extracts having the major components resveratrol and curcumin, respectively, were used for the induction of cryptic and bioactive metabolites in an endophytic fungus Colletotrichum gloeosporioides isolated from Syzygium cumini. The increase in total amount of crude compounds in grape skin and turmeric extract treated cultures was 272.48 and 174.32%, respectively, compared to the untreated control. Among six human pathogenic bacteria tested, the maximum inhibitory activity was found against Aeromonas hydrophila IMS/GN11 while no inhibitory activity was observed against Enterococcus faecalis IMS/GN7. The crude compounds derived from turmeric extract treated cultures showed the highest DPPH free radicals scavenging activity (86.46% inhibition) followed by compounds from grape skin treated cultures (11.80% inhibition) and the control cultures (1.92% inhibition). Both the treatments significantly (p ≤ 0.05) increased the antibacterial and antioxidant activities of...
Journal of Nanomaterials & Molecular Nanotechnology, 2016
Biofabrication of Antibacterial and Antioxidant Silver Nanoparticles (Agnps) by an Endophytic Fun... more Biofabrication of Antibacterial and Antioxidant Silver Nanoparticles (Agnps) by an Endophytic Fungus Pestalotia Sp. Isolated from Madhuca Longifolia Particles of metals or other materials in nanometre size are called as nanoparticles (NPs). Of ten endophytic fungi screened, seven endophytic fungi namely Alternaria alternata, Botryodiplodia sp., Pestalotia sp., Fusarium sp., Aspergillus sp. Aschersonia sp. and Phomopsis sp. were able to synthesize silver nanoparticles. Silver metal nanopartites were synthesised successfully by both mycelium as well as cell filtrate of Pestalotia sp., which was initially observed by spectrometric analysis. TEM pictures revealed the synthesis of angular shape of silver nanoparticles like trigonal, pentagonal, hexagonal, few of cuboids and some were of spherical in shape too. Most of nanoparticles (76%) were found below the size of 40 nm. FTIR spectra peaks showed the presence of -NH, CO, C=C and C-H containing organic metabolites which might play a role in stabilizing the nanoparticles. Silver nanoparticles solution (0.5 mM) inhibited the growth significantly than control against all pathogenic bacteria tested. Mycosynthesized AgNPs were most active against Aeromonas hydrophila @2 μg/ml IC50 followed by Staphylococcus aureus (6 μg/ml), Escherichia coli (8μg/ml), Morganella morganii (24 μg/ml), Salmonella typhi (42 μg/ml), Enterococcus faecalis (40 μg/ml) and Klebsiella pneumoniae (50 μg/ml) respectively. Silver nanoparticles had also shown antioxidant activity with DPPH free radical scavenging with inhibitory concentration (IC50) at 47 μg /ml. To combat with new emerging pathogenic bacteria that threat our society by causing dreadful diseases, we require the development of effective therapeutics. Thus, eco-friendly synthesised antimicrobial and antioxidant silver nanoparticles allow us to suitably employing their application in nanoparticles mediated drug delivery and therapy of diseases.
PloS one, 2016
The endophytic Streptomyces coelicolor strain AZRA 37 was isolated from the surface sterilized ro... more The endophytic Streptomyces coelicolor strain AZRA 37 was isolated from the surface sterilized root of Azadirachta indica A. Juss., commonly known as neem plant in India. Since only a few reports are available regarding epigenetic modulations of microbial entities, S. coelicolor was treated with different concentrations of 5-azacytidine for this purpose and evaluated for its antibacterial potential against five human pathogenic bacteria (Aeromonas hydrophila IMS/GN11, Enterococcus faecalis IMS/GN7, Salmonella typhi MTCC 3216, Shigella flexneri ATCC 12022 and Staphylococcus aureus ATCC 25923). The crude extract obtained from cultures treated with 25 μM concentration of 5-azacytidine, was found effective against all five pathogenic bacteria tested while the untreated control was only active against 3 pathogenic bacteria. HPLC analysis of crude compounds from treated cultures showed a greater number of compounds than that of the control. Extraction of whole cell protein and its SDS PAG...
Vegetos- An International Journal of Plant Research, 2015
Seventeen isolates of Pseudomonas fluo-rescens (Pf) were examined for growth promotion and the in... more Seventeen isolates of Pseudomonas fluo-rescens (Pf) were examined for growth promotion and the induction of systemic resistance against early blight disease of tomato. A noticeable in-crease in shoot and root length was observed in plants treated with P. fluorescens. However, the root development was reduced by a combination of P. fluorescens and Alternaria alternata (A. alter-nata). P. fluorescens isolates systemically induced resistance against early blight of tomato caused by A. alternata and reduced (approx.18–42%) the dis-ease significantly. All the isolates of P. fluorescens produced salicylic acid (SA) in King's B (KB) broth and induced its accumulation in tomato leaf within 24 h of bacterial inoculation. SA levels were signifi-cantly increased in plants treated with bacteria compared to the split control from one to five days following inoculation. Low SA concentration (0.1–0.5 mg/ml) did not inhibit mycelial growth of A. alternata in vitro, contrary to inhibition at high concentrations. The exogenously applied SA first accumulates in host tissues and induces resistance, however, endogenous SA accumulation in plant tissue is considered to be involved in induced sys-temic resistance to early blight disease of tomato caused by A. alternata.
Symbiosis, 2015
An endophytic Bacillus amyloliquefaciens subsp. subtilis was isolated from surface sterilized see... more An endophytic Bacillus amyloliquefaciens subsp. subtilis was isolated from surface sterilized seedlings of tropical corn. To evaluate the hypothesis that this endophyte is defensive in nature and determine the mechanisms of host defense we examined the effects of the endophyte on pathogens and host disease resistance genes. The bacterial endophyte showed antifungal activity against fungal pathogens Fusarium moniliforme, Colletotrichum gloeosporioides and Aspergillus flavus. Plant protection activity was also observed in Indian popcorn seedlings inoculated with the endophyte against F. moniliforme. Gene expression analysis was conducted and demonstrated that up-regulation of several defense genes in corn was greater after 48 hours of pathogen challenge than 24 hours. Plant defense pathways triggered by the endophytic bacterium appeared to be SA (salicylic acid) independent. The abundance of the zm Jasmonic acid-induced gene expression was greater in pathogen challenged plants pre-treated with the endophytic bacterium than in the plants challenged only with pathogen. Pre-treatment with the endophytic bacterium resulted in a more intense induction of maize pathogenesis related protein genes PR-1 and PR-10 during interaction with F. moniliforme compared to plants that were treated only with the fungal pathogen.