RAJREEPA TALUKDAR - Academia.edu (original) (raw)
Papers by RAJREEPA TALUKDAR
South African Journal of Botany
Indian Journal Of Agricultural Research, 2020
Background: Seed borne endophytic fungi play an important role in seed germination and plant heal... more Background: Seed borne endophytic fungi play an important role in seed germination and plant health. There are ubiquitous and have been found associated in every plant species investigated so far. They colonize plant seeds without causing any disease and are often vertically transmitted. Despite their occurrence, seed borne endophytic fungi are poorly investigated and their role for application in agriculture is still to be elucidated. Methods: In the present study endophytic fungi associated with seeds of some indigenous rice varieties of North East, India was investigated. The isolates were determined for IAA activity in-vitro and antifungal activity against rice pathogen, Magnaporthe grisea. Crude metabolites obtained from potent isolates were characterized by GCMS analysis to reveal the presence of bioactive compounds. Result: Our result indicated that commonly isolated fungal genera were Aspergillus, Fusarium, Gliocladium, Mucor, Penicillium, Bipolaris, Basidiobolus and Mycelia...
Zanthoxylum oxyphyllum Edgew. is a medicinal plant widely been used by the local tribal communiti... more Zanthoxylum oxyphyllum Edgew. is a medicinal plant widely been used by the local tribal communities of Assam as an alternative source of medicine for the treatment of various diseases. In the present study, endophytic fungi associated with Z. oxyphyllum were undertaken with an aim to investigate the isolates for their antimicrobial potential. The endophytic fungi were recovered using four different media, namely, Malt Extract Agar (MEA) media, Potato Dextrose Agar (PDA) media, Water Agar (WA) media and media amended with the Plant Extract (PEA) from samples collected from three sites. Altogether, 18 isolates of endophytic fungi were isolated from 150 surface sterilized and healthy leaf fragments. Colletotrichum was found to be dominant endophytic genus with 7 different species. Other isolated endophytic fungal genera were Fusarium, Curvularia, Aspergillus, Corynespora and isolates belonging non-sporulating fungi categorised as Mycelia Sterilia. The endophytic fungi were determined f...
The purpose of this work was to evaluate the antimicrobial potential of endophytic fungi isolated... more The purpose of this work was to evaluate the antimicrobial potential of endophytic fungi isolated from leaves and stems of Suaeda maritima and Suaeda monoica. Many endophytes were isolated by using potato dextrose agar (PDA) medium. All the endophytic isolates were identified by using standard taxonomic keys and monographs. From a total of 16 isolates, nine potent strains were taken for further study. The fungal culture was extracted with ethyl acetate and used as a crude extract for checking antimicrobial activities by well diffusion method. The crude extract showed different inhibitory activity against all pathogens, the zones of inhibition obtained was between 2 and 12 mm. SM-EF 3 crude extract showed high zone of inhibition of 11.6±0.57 mm against Salmonella typhi, 8.3±1.52 mm against Trichophyton rubrum, respectively. The present findings concludes that SM-EF 3, SM-EF 7 and SM-EF 9 showed comparatively higher antimicrobial activity against all the human pathogens. From the present work, it is possible to conclude that these microorganisms could be promising source of bioactive compounds and warrant further study.
Journal of Applied Pharmaceutical Science, 2020
Endophytic fungi from healthy leaf tissues of Houttuynia cordata Thunb., a widely used ethnomedic... more Endophytic fungi from healthy leaf tissues of Houttuynia cordata Thunb., a widely used ethnomedicinal plant of Northeast India, were investigated, and an attempt has been made to characterize the antimicrobial metabolites from some potent endophytic strains. Altogether, 56 endophytic fungal isolates were obtained from surface-sterilized leaf fragments of H. cordata. The endophytes consisted of fungi belonging to genera Colletotrichum, Curvularia, Bipolaris, Corynespora, and Pseudozyma and non-sporulating fungi categorized as mycelia sterilia. Assay for antimicrobial activity revealed that 73.07% of the isolates showed activity against the test pathogens in varying degrees, whereas 92.32% of the isolates showed anticandida activity against Candida albicans. Among the isolates, two endophytic fungi identified as Colletotrichum coccodes and Phyllosticta capitalensis showed a significant antimicrobial activity against all the test pathogens. The metabolites obtained from C. coccodes revealed the presence of different functional groups and bioactive compounds such as geranylgeraniol, farnesol, hexacosanol, oleic acid, and squalene. Metabolites obtained from P. capitalensis also showed various functional groups and the presence of bioactive compound, 1-Octacosanol among several others. The study indicated that the ethnomedicinal plants are colonized by the rich diversity of endophytic fungi with antimicrobial activity. A further detailed investigation could practically lead to the development of pharmaceutical agents in the future.
Plant Science Today, 2021
Zanthoxylum oxyphyllum Edgew. is a medicinal plant widely been used by the local tribal communiti... more Zanthoxylum oxyphyllum Edgew. is a medicinal plant widely been used by the local tribal communities of Assam as an alternative source of medicine for the treatment of various diseases. In the present study, endophytic fungi associated with Z. oxyphyllum were undertaken with an aim to investigate the isolates for their antimicrobial potential. The endophytic fungi were recovered using four different media, namely, Malt Extract Agar (MEA) media, Potato Dextrose Agar (PDA) media, Water Agar (WA) media and media amended with the Plant Extract (PEA) from samples collected from three sites. Altogether, 18 isolates of endophytic fungi were isolated from 150 surface sterilized and healthy leaf fragments. Colletotrichum was found to be dominant endophytic genus with 7 different species. Other isolated endophytic fungal genera were Fusarium, Curvularia, Aspergillus, Corynespora and isolates belonging non-sporulating fungi categorised as Mycelia Sterilia. The endophytic fungi were determined f...
Journal of Applied Pharmaceutical Science, 2020
Endophytic fungi from healthy leaf tissues of Houttuynia cordata Thunb., a widely used ethnomedic... more Endophytic fungi from healthy leaf tissues of Houttuynia cordata Thunb., a widely used ethnomedicinal plant of Northeast India, were investigated, and an attempt has been made to characterize the antimicrobial metabolites from some potent endophytic strains. Altogether, 56 endophytic fungal isolates were obtained from surface-sterilized leaf fragments of H. cordata. The endophytes consisted of fungi belonging to genera Colletotrichum, Curvularia, Bipolaris, Corynespora, and Pseudozyma and non-sporulating fungi categorized as mycelia sterilia. Assay for antimicrobial activity revealed that 73.07% of the isolates showed activity against the test pathogens in varying degrees, whereas 92.32% of the isolates showed anticandida activity against Candida albicans. Among the isolates, two endophytic fungi identified as Colletotrichum coccodes and Phyllosticta capitalensis showed a significant antimicrobial activity against all the test pathogens. The metabolites obtained from C. coccodes rev...
An endophytic fungus isolated from healthy leaf tissues of Houttuynia cordata Thunb., an ethnomed... more An endophytic fungus isolated from healthy leaf tissues of Houttuynia cordata Thunb., an ethnomedicinal plant of North East India, showed a considerable amount of antimicrobial activity. The ethyl acetate extract of the fungal culture filtrates displayed promising antimicrobial activity against a panel of clinically significant pathogens including Candida albicans, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Bioassay guided purification of the organic extract using column and thin layer chromatography yielded a pure homogenous compound which was identified using spectroscopic methods (essentially by 1H NMR and MS) as tyrosol, a well-known phenylethanoid present in several natural sources. Besides, molecular docking studies against tyrosyl tRNA synthetases (TyrRS) of S. aureus (PDB ID: 1JIL) and E. coli (PDB ID: 1VBM), and CYP45014α-lanosterol demethylase (CYP51) of C. albicans (PDB ID: 5FSA) revealed tyrosol has a strong binding affinity with the enzyme acti...
Frontiers in Bioengineering and Biotechnology
An endophytic fungus isolated from healthy leaf tissues of Houttuynia cordata Thunb., an ethnomed... more An endophytic fungus isolated from healthy leaf tissues of Houttuynia cordata Thunb., an ethnomedicinal plant of North East India, showed a considerable amount of antimicrobial activity. The ethyl acetate extract of the fungal culture filtrates displayed promising antimicrobial activity against a panel of clinically significant pathogens including Candida albicans, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Bioassay guided purification of the organic extract using column and thin layer chromatography yielded a pure homogenous compound which was identified using spectroscopic methods (essentially by 1H NMR and MS) as tyrosol, a well-known phenylethanoid present in several natural sources. Besides, molecular docking studies against tyrosyl tRNA synthetases (TyrRS) of S. aureus (PDB ID: 1JIL) and E. coli (PDB ID: 1VBM), and CYP45014α-lanosterol demethylase (CYP51) of C. albicans (PDB ID: 5FSA) revealed tyrosol has a strong binding affinity with the enzyme acti...
Journal of Bio Innovation
Endophytic fungi were isolated from healthy leaf tissues of three ethno-medicinal plants of Assam... more Endophytic fungi were isolated from healthy leaf tissues of three ethno-medicinal plants of Assam, namely, Houttuynia cordata, Eryngium foetidum and Zanthoxylum oxyphyllum which are widely used in folk medicine to treat various ailments. Endophytic fungi were isolated from the surface sterilized leaves of the three plants cultivated using three different types of solid agar media. A total of 214 endophytic fungal isolates were isolated from all of the three plants belonging to 12 different genera. Maximum number of endophytic fungal isolates was recovered from E. foetidum (84), followed by Z oxyphyllum and minimum was recovered from H. cordata (56). The most dominant fungal genus was found to be that of Colletotrichum with 107 isolates, followed morphotypes of by Mycelia Sterilia (69) and recovered from all of the three plants studied. Antimicrobial activity assay of the crude secondary metabolites extracted from the endophytic fungal isolates was performed using agar cup diffusion method. It revealed that 10 of the fungal species showed significant activity against all the test pathogens in varying degrees. Among all the isolates, endophytic fungi Colletotrichum coccodes and C. siamense showed maximum significant antimicrobial activity followed by other potent isolates like C. gleosporioides, Fusarium oxysporum, Curvularia sp., Penicillium sp., Scopulariopsis sp. and Cladosporium fulvum. The study thus indicated that the ethno-medicinal plants of Assam are colonized by a diverse range of endophytic fungi with prominent antimicrobial activity. Future investigation in this field would aid in the development of novel pharmaceutical agents.
Acta Amazonica, 2004
Das plantas tóxicas da Amazônia Palicourea longiflora e Strychnos cogens foram isolados 571 fungo... more Das plantas tóxicas da Amazônia Palicourea longiflora e Strychnos cogens foram isolados 571 fungos endofíticos e 74 bactérias endofíticas. Palicourea longiflora (Rubiaceae) e outras espécies desse gênero estão relacionadas a 90% das mortes de gado na região Amazônica. Strychnos cogens (Loganiaceae) e outras espécies de Strychnos são utilizadas pelos indígenas na confecção de "curares". Entre os endófitos isolados de P. longiflora foram identificados os fungos: Colletotrichum sp. e seu telemorfo Glomerella sp., Guignardia sp., Aspergillus niger, Phomopsis sp. e Xylaria sp., além da bactéria Burkholderia gladioli, pertencente a um grupo de fixadoras de nitrogênio. Dos isolados de S. cogens foram identificados os fungos: Colletotrichum sp., Guignardia sp., Aspergillus niger e Trichoderma sp. Uma amostra de 79 isolados fúngicos teve seus metabólitos extracelulares bioensaiados contra microrganismos patogênicos e fitopatogênicos: 19 isolados inibiram um ou mais microrganismos-t...
South African Journal of Botany
Indian Journal Of Agricultural Research, 2020
Background: Seed borne endophytic fungi play an important role in seed germination and plant heal... more Background: Seed borne endophytic fungi play an important role in seed germination and plant health. There are ubiquitous and have been found associated in every plant species investigated so far. They colonize plant seeds without causing any disease and are often vertically transmitted. Despite their occurrence, seed borne endophytic fungi are poorly investigated and their role for application in agriculture is still to be elucidated. Methods: In the present study endophytic fungi associated with seeds of some indigenous rice varieties of North East, India was investigated. The isolates were determined for IAA activity in-vitro and antifungal activity against rice pathogen, Magnaporthe grisea. Crude metabolites obtained from potent isolates were characterized by GCMS analysis to reveal the presence of bioactive compounds. Result: Our result indicated that commonly isolated fungal genera were Aspergillus, Fusarium, Gliocladium, Mucor, Penicillium, Bipolaris, Basidiobolus and Mycelia...
Zanthoxylum oxyphyllum Edgew. is a medicinal plant widely been used by the local tribal communiti... more Zanthoxylum oxyphyllum Edgew. is a medicinal plant widely been used by the local tribal communities of Assam as an alternative source of medicine for the treatment of various diseases. In the present study, endophytic fungi associated with Z. oxyphyllum were undertaken with an aim to investigate the isolates for their antimicrobial potential. The endophytic fungi were recovered using four different media, namely, Malt Extract Agar (MEA) media, Potato Dextrose Agar (PDA) media, Water Agar (WA) media and media amended with the Plant Extract (PEA) from samples collected from three sites. Altogether, 18 isolates of endophytic fungi were isolated from 150 surface sterilized and healthy leaf fragments. Colletotrichum was found to be dominant endophytic genus with 7 different species. Other isolated endophytic fungal genera were Fusarium, Curvularia, Aspergillus, Corynespora and isolates belonging non-sporulating fungi categorised as Mycelia Sterilia. The endophytic fungi were determined f...
The purpose of this work was to evaluate the antimicrobial potential of endophytic fungi isolated... more The purpose of this work was to evaluate the antimicrobial potential of endophytic fungi isolated from leaves and stems of Suaeda maritima and Suaeda monoica. Many endophytes were isolated by using potato dextrose agar (PDA) medium. All the endophytic isolates were identified by using standard taxonomic keys and monographs. From a total of 16 isolates, nine potent strains were taken for further study. The fungal culture was extracted with ethyl acetate and used as a crude extract for checking antimicrobial activities by well diffusion method. The crude extract showed different inhibitory activity against all pathogens, the zones of inhibition obtained was between 2 and 12 mm. SM-EF 3 crude extract showed high zone of inhibition of 11.6±0.57 mm against Salmonella typhi, 8.3±1.52 mm against Trichophyton rubrum, respectively. The present findings concludes that SM-EF 3, SM-EF 7 and SM-EF 9 showed comparatively higher antimicrobial activity against all the human pathogens. From the present work, it is possible to conclude that these microorganisms could be promising source of bioactive compounds and warrant further study.
Journal of Applied Pharmaceutical Science, 2020
Endophytic fungi from healthy leaf tissues of Houttuynia cordata Thunb., a widely used ethnomedic... more Endophytic fungi from healthy leaf tissues of Houttuynia cordata Thunb., a widely used ethnomedicinal plant of Northeast India, were investigated, and an attempt has been made to characterize the antimicrobial metabolites from some potent endophytic strains. Altogether, 56 endophytic fungal isolates were obtained from surface-sterilized leaf fragments of H. cordata. The endophytes consisted of fungi belonging to genera Colletotrichum, Curvularia, Bipolaris, Corynespora, and Pseudozyma and non-sporulating fungi categorized as mycelia sterilia. Assay for antimicrobial activity revealed that 73.07% of the isolates showed activity against the test pathogens in varying degrees, whereas 92.32% of the isolates showed anticandida activity against Candida albicans. Among the isolates, two endophytic fungi identified as Colletotrichum coccodes and Phyllosticta capitalensis showed a significant antimicrobial activity against all the test pathogens. The metabolites obtained from C. coccodes revealed the presence of different functional groups and bioactive compounds such as geranylgeraniol, farnesol, hexacosanol, oleic acid, and squalene. Metabolites obtained from P. capitalensis also showed various functional groups and the presence of bioactive compound, 1-Octacosanol among several others. The study indicated that the ethnomedicinal plants are colonized by the rich diversity of endophytic fungi with antimicrobial activity. A further detailed investigation could practically lead to the development of pharmaceutical agents in the future.
Plant Science Today, 2021
Zanthoxylum oxyphyllum Edgew. is a medicinal plant widely been used by the local tribal communiti... more Zanthoxylum oxyphyllum Edgew. is a medicinal plant widely been used by the local tribal communities of Assam as an alternative source of medicine for the treatment of various diseases. In the present study, endophytic fungi associated with Z. oxyphyllum were undertaken with an aim to investigate the isolates for their antimicrobial potential. The endophytic fungi were recovered using four different media, namely, Malt Extract Agar (MEA) media, Potato Dextrose Agar (PDA) media, Water Agar (WA) media and media amended with the Plant Extract (PEA) from samples collected from three sites. Altogether, 18 isolates of endophytic fungi were isolated from 150 surface sterilized and healthy leaf fragments. Colletotrichum was found to be dominant endophytic genus with 7 different species. Other isolated endophytic fungal genera were Fusarium, Curvularia, Aspergillus, Corynespora and isolates belonging non-sporulating fungi categorised as Mycelia Sterilia. The endophytic fungi were determined f...
Journal of Applied Pharmaceutical Science, 2020
Endophytic fungi from healthy leaf tissues of Houttuynia cordata Thunb., a widely used ethnomedic... more Endophytic fungi from healthy leaf tissues of Houttuynia cordata Thunb., a widely used ethnomedicinal plant of Northeast India, were investigated, and an attempt has been made to characterize the antimicrobial metabolites from some potent endophytic strains. Altogether, 56 endophytic fungal isolates were obtained from surface-sterilized leaf fragments of H. cordata. The endophytes consisted of fungi belonging to genera Colletotrichum, Curvularia, Bipolaris, Corynespora, and Pseudozyma and non-sporulating fungi categorized as mycelia sterilia. Assay for antimicrobial activity revealed that 73.07% of the isolates showed activity against the test pathogens in varying degrees, whereas 92.32% of the isolates showed anticandida activity against Candida albicans. Among the isolates, two endophytic fungi identified as Colletotrichum coccodes and Phyllosticta capitalensis showed a significant antimicrobial activity against all the test pathogens. The metabolites obtained from C. coccodes rev...
An endophytic fungus isolated from healthy leaf tissues of Houttuynia cordata Thunb., an ethnomed... more An endophytic fungus isolated from healthy leaf tissues of Houttuynia cordata Thunb., an ethnomedicinal plant of North East India, showed a considerable amount of antimicrobial activity. The ethyl acetate extract of the fungal culture filtrates displayed promising antimicrobial activity against a panel of clinically significant pathogens including Candida albicans, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Bioassay guided purification of the organic extract using column and thin layer chromatography yielded a pure homogenous compound which was identified using spectroscopic methods (essentially by 1H NMR and MS) as tyrosol, a well-known phenylethanoid present in several natural sources. Besides, molecular docking studies against tyrosyl tRNA synthetases (TyrRS) of S. aureus (PDB ID: 1JIL) and E. coli (PDB ID: 1VBM), and CYP45014α-lanosterol demethylase (CYP51) of C. albicans (PDB ID: 5FSA) revealed tyrosol has a strong binding affinity with the enzyme acti...
Frontiers in Bioengineering and Biotechnology
An endophytic fungus isolated from healthy leaf tissues of Houttuynia cordata Thunb., an ethnomed... more An endophytic fungus isolated from healthy leaf tissues of Houttuynia cordata Thunb., an ethnomedicinal plant of North East India, showed a considerable amount of antimicrobial activity. The ethyl acetate extract of the fungal culture filtrates displayed promising antimicrobial activity against a panel of clinically significant pathogens including Candida albicans, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Bioassay guided purification of the organic extract using column and thin layer chromatography yielded a pure homogenous compound which was identified using spectroscopic methods (essentially by 1H NMR and MS) as tyrosol, a well-known phenylethanoid present in several natural sources. Besides, molecular docking studies against tyrosyl tRNA synthetases (TyrRS) of S. aureus (PDB ID: 1JIL) and E. coli (PDB ID: 1VBM), and CYP45014α-lanosterol demethylase (CYP51) of C. albicans (PDB ID: 5FSA) revealed tyrosol has a strong binding affinity with the enzyme acti...
Journal of Bio Innovation
Endophytic fungi were isolated from healthy leaf tissues of three ethno-medicinal plants of Assam... more Endophytic fungi were isolated from healthy leaf tissues of three ethno-medicinal plants of Assam, namely, Houttuynia cordata, Eryngium foetidum and Zanthoxylum oxyphyllum which are widely used in folk medicine to treat various ailments. Endophytic fungi were isolated from the surface sterilized leaves of the three plants cultivated using three different types of solid agar media. A total of 214 endophytic fungal isolates were isolated from all of the three plants belonging to 12 different genera. Maximum number of endophytic fungal isolates was recovered from E. foetidum (84), followed by Z oxyphyllum and minimum was recovered from H. cordata (56). The most dominant fungal genus was found to be that of Colletotrichum with 107 isolates, followed morphotypes of by Mycelia Sterilia (69) and recovered from all of the three plants studied. Antimicrobial activity assay of the crude secondary metabolites extracted from the endophytic fungal isolates was performed using agar cup diffusion method. It revealed that 10 of the fungal species showed significant activity against all the test pathogens in varying degrees. Among all the isolates, endophytic fungi Colletotrichum coccodes and C. siamense showed maximum significant antimicrobial activity followed by other potent isolates like C. gleosporioides, Fusarium oxysporum, Curvularia sp., Penicillium sp., Scopulariopsis sp. and Cladosporium fulvum. The study thus indicated that the ethno-medicinal plants of Assam are colonized by a diverse range of endophytic fungi with prominent antimicrobial activity. Future investigation in this field would aid in the development of novel pharmaceutical agents.
Acta Amazonica, 2004
Das plantas tóxicas da Amazônia Palicourea longiflora e Strychnos cogens foram isolados 571 fungo... more Das plantas tóxicas da Amazônia Palicourea longiflora e Strychnos cogens foram isolados 571 fungos endofíticos e 74 bactérias endofíticas. Palicourea longiflora (Rubiaceae) e outras espécies desse gênero estão relacionadas a 90% das mortes de gado na região Amazônica. Strychnos cogens (Loganiaceae) e outras espécies de Strychnos são utilizadas pelos indígenas na confecção de "curares". Entre os endófitos isolados de P. longiflora foram identificados os fungos: Colletotrichum sp. e seu telemorfo Glomerella sp., Guignardia sp., Aspergillus niger, Phomopsis sp. e Xylaria sp., além da bactéria Burkholderia gladioli, pertencente a um grupo de fixadoras de nitrogênio. Dos isolados de S. cogens foram identificados os fungos: Colletotrichum sp., Guignardia sp., Aspergillus niger e Trichoderma sp. Uma amostra de 79 isolados fúngicos teve seus metabólitos extracelulares bioensaiados contra microrganismos patogênicos e fitopatogênicos: 19 isolados inibiram um ou mais microrganismos-t...