Soma Barman - Academia.edu (original) (raw)
Papers by Soma Barman
Beneficial Microbes in Agro-Ecology, 2020
Recent Advancement in Microbial Biotechnology, 2021
Indian journal of experimental biology, 2013
Phosphorus is one of the key factors that regulate soil fertility. Its deficiencies in soil are l... more Phosphorus is one of the key factors that regulate soil fertility. Its deficiencies in soil are largely replenished by chemical fertilizers. The present study was aimed to isolate efficient phosphate solubilizing fungal strains from Eisenia fetida vermicompost. Out of total 30 fungal strains the most efficient phosphate solubilizing one was Emericella (Aspergillus) nidulans V1 (MTCC 11044), identified by custom sequencing of beta-tubulin gene and BLAST analysis. This strain solubilized 13 to 36% phosphate from four different rock phosphates. After three days of incubation of isolated culture with black Mussorie phosphate rock, the highest percentage of phosphate solubilization was 35.5 +/- 1.01 with a pH drop of 4.2 +/- 0.09. Kinetics of solubilization and acid production showed a linear relationship until day five of incubation. Interestingly, from zero to tenth day of incubation, solubility of soil phosphate increased gradually from 4.31 +/- 1.57 to 13.65 +/- 1.82 (mg kg(-1)) reco...
Honey is a traditionally used medicine for topical treatment, infected wounds and various other i... more Honey is a traditionally used medicine for topical treatment, infected wounds and various other infections. It can be effective on antibiotic resistance strains of bacteria as well (Chute et al. 2010). Antibacterial activity of honey varies with origin and processes. Honey has been used as a folklore medicine for many different purposes: as a laxative, as a natural cure for diarrhea and upset stomach, for coughs and sore throats. Honey is an ancient remedy in the Middle East, India, China and Africa for many centuries and has been used in the treatment and prevention of the common cold and various upper respiratory tract infections (Molan, 1992, Zulma and Lulat, 1989).
Rapid increase in global human population with escalating crisis for food will continue because t... more Rapid increase in global human population with escalating crisis for food will continue because the land area for agriculture is not only limited but also equivalently shrinking overtime. Therefore, the need of the time is to enhance crop productivity which eventually is leading to substantial loss in soil health due to extensive use of agrochemicals. Intensive agricultural practices (reliance on agrochemicals, conventional tillage, clean cultivation techniques, etc.) greatly deteriorate ecology and human health. Therefore, establishing an eco-friendly mechanism through significant substitution of synthetic chemical fertilizers is one of the major goals of sustainable agricultural concepts. In this context, meaningful research program on the utilization of “beneficial microorganisms” in agriculture has tremendous potential to revolutionize the agro-industry. These mutualistic beneficial microorganisms accelerate the microbial process which eventually augments the availability of nut...
Environmental Science: Nano
Nano-enabled agriculture is a vibrant research area; nonetheless, reports on effective nanofertil... more Nano-enabled agriculture is a vibrant research area; nonetheless, reports on effective nanofertilizers are rather scant.
![Research paper thumbnail of Corrigendum to “Appraisal of lignocellusoic biomass degrading potential of three earthworm species using vermireactor mediated with spent mushroom substrate: Compost quality, crystallinity, and microbial community structural analysis” [Sci. Total Environ. 716 (2020) 135215]](https://attachments.academia-assets.com/75836551/thumbnails/1.jpg)
](Science of The Total Environment
Chemosphere
Brick kiln coal ashes (BKCAs) are one of the major toxic byproducts of the rapidly growing constr... more Brick kiln coal ashes (BKCAs) are one of the major toxic byproducts of the rapidly growing construction industry in developing countries. However, eco-friendly recycling avenues for BKCAs are yet to be explored. The major objectives of the present research were to evaluate the viability of vermitechnology in transforming BKCAs into valuable products, and to examine the metal detoxification potential of Eisenia fetida BKCA-based feedstocks. BKCAs were mixed in large scale with cow dung (CD) in 1:1 and 2:1 ratios, for vermicomposting and aerobic composting; performance was assessed in comparison with CD. Vermiconverted-BKCA was then used as organic fertilizer for rice grown in poorly fertile soil. Acidic nature of BKCA feedstocks was neutralized by 30-86% in the vermireactors. Total N and available P concentrations significantly increased in the vermireactors supplemented with considerable mineralization of total organic C. Exorbitantly high K and S contents were pacified to a normal range after vermicomposting. Greater improvement in microbial biomass, respiration, fungal and bacterial growth was observed under vermicomposting against aerobic composting. Consequently, urease and phosphatase activity increased by 1-4 folds in the BKCA based vermibeds. Bioavailability of toxic metals reduced by 41-74% in the vermicomposted BKCAs. High metal accumulation by the earthworms resulted in substantial reduction of pollution load in the finished product. The field experiment demonstrated that vermiconverted-BKCA could be utilized as potential organic fertilizer for rice production, soil fertility rejuvenation, and metal detoxification. Overall, the study reveals that E. fetida could be used as an efficient contender for sanitization of toxic BKCAs.
Science of The Total Environment
Spent mushroom substrate (SMS) is a recalcitrant lignocellulosic waste. Recycling of SMS through ... more Spent mushroom substrate (SMS) is a recalcitrant lignocellulosic waste. Recycling of SMS through composting has been reported; however, the process is lengthy due to its complex biochemical composition. Although vermitechnology is known for its high efficiency, it has rarely been applied to recycle SMS. In this study, the qualitative value of vermicomposted SMS mediated by three earthworm species (i.e., Eisenia fetida, Eudrilus eugeniae, and Perionyx excavatus) was evaluated on the basis of nutrient availability, microbial activity, phospholipid fatty acid (PLFA) profiles, and seed germination assays. Degradation profiles of the lignocellulosic substrate in the vermireactors were assessed by monitoring the changes in crystallinity and distribution of functional groups using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy, respectively. Total organic carbon decreased by 1.4-3.5 folds with approximately 2.1-2.4 folds increase in nitrogen and phosphorus availability in all vermibeds. Interestingly, pH declined in the Eisenia and Eudrilus systems but increased in the Perionyx-vermibeds. XRD-derived crystallinity index was reduced significantly by 1.37 folds in Perionyx-vermicompost with concurrent microbial enrichment. Further, profuse abundance of vital functional groups (CO, NH, and OH) was clearly observed in the vermicompost with Perionyx followed by that with Eisenia. Moreover, PLFA illustrated significant variations in fatty acid distributions and microbial communities of the three vermicomposting systems. The seed germination assay showed that the germination index and relative root-shoot vigor of Perionyx-vermicompost treated seeds were 1.05-1.30 times greater than those of Eisenia and Eudrilus vermicompost treated ones. The results suggest that SMS degradability was affected by the growth of a healthy microbial community through vermicomposting.
NASS Journal of Agricultural Sciences
Silver nanoparticles (AgNP) synthesized from It influenced the inherent soil properties like bulk... more Silver nanoparticles (AgNP) synthesized from It influenced the inherent soil properties like bulk density (BD), water holding capacity (WHC), available N, P, K, urease, phosphatase activity and TOC. The apparent increment WHC, N, P, K, urease, and phosphatase in soil were observed whereas reduction of BD was noticed. Due to application of nanosolutions the pH of the soil shifted towards neutrality from 0 to 60 days. Moreover, they also did not have any toxicity upon plant as well as earthworm ecosystem.
Annals of Agrarian Science
Abstract Three potent strains of lactic acid bacteria (LAB) with bacteriocin producing abilities ... more Abstract Three potent strains of lactic acid bacteria (LAB) with bacteriocin producing abilities have been isolated from homemade buttermilk. They can produce proteinaceous bacteriocins in the medium which are resistant to heat (121 °C for 15 min) and can tolerate range of pH from 3.0 to 11.0. They were found to be Gram positive, non-motile, non-endospore forming, coccoid structures. The strains LABW1 and LABW3 were present in chains while LABW4 were present singly or in pairs. By considering the 16S rDNA sequence homologies and phylogenetic analysis LABW1 and LABW3 were identified as Lactococcus lactis subsp. hordniae where as LABW4 was identified as Lactococcus lactis subsp. lactis. Maximum extracellular bacteriocin production by the isolates takes place in MRS medium (pH 5.0–7.0) at 28 °C and it showed strong correlation with bacterial growth. They started producing bacteriocin at early exponential phase (400 AU/ml) and reached its peak at the early stationary phase (12800 AU/ml for LABW1 and LABW3 and 25600 AU/ml for LABW4) which remain unchanged up to late stationary phase. The bacteriocin of the isolates had an antibacterial spectrum both against Gram positive as well as Gram negative pathogenic bacterial strains. The inhibition of Gram negative bacteria by bacteriocin of LAB is an unusual phenomenon. It exhibits bacteriocidal action on Staphylococcus aureus MTCC96 and Pseudomonas aeruginosa MTCC741. Prominent morphological aberrations, cell shrinkages and pore formations on cell wall of pathogenic bacterial cells upon bacteriocin treatment as evidenced from scanning electron microscope (SEM).
Asian Journal of Pharmaceutical and Clinical Research
Objectives: Endophytic fungi are considered as an important source of bioactive metabolites. The ... more Objectives: Endophytic fungi are considered as an important source of bioactive metabolites. The present study focused on the isolation of potent endophytic fungal strains from well-known medicinal plant Rauvolfia serpentina L. Benth. having biological activities.Materials & Methods: Fungal endophytes were isolated from aerial parts of the plant and the potent strain was selected on the basis of antibacterial activities of cell-free supernatant (CFS). Ethyl acetate (EA) extraction of CFS was done and mode of action of EA fraction was checked against pathogenic bacteria. EA fraction was also analyzed by thin-layer chromatography (TLC). In addition, antioxidant activity was checked by 1,1-Diphenyl- 2-picrylhydrazyl-free radical scavenging assay and anticancer activity was checked against breast cancer cell line MCF-7 by MTT assay.Results: Among the different endophytic fungal isolates, CFS of Alternaria sp. RL4 produced prominent zones of inhibition against numbers of Gram-positive pa...
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences
PLOS ONE
Provide an accurate summary of the background, research objectives, including details of the spec... more Provide an accurate summary of the background, research objectives, including details of the species or strain of animal used, key methods, principal findings and conclusions of the study.
Journal of Nanoscience and Nanotechnology
Silver nanoparticles contribute a giant share to the realm of modern nanobiotechnology. Their uti... more Silver nanoparticles contribute a giant share to the realm of modern nanobiotechnology. Their utility as antimicrobial agents is also well documented. Green synthesis of nanoparticle has several advantages over its chemical synthesis. In the present study, Thuja occidentalis leaf extract mediated silver nanoparticles were prepared without using a stabilizing agent and tested for their anticancer and anti-microbial activity. Thuja occidentalis leaf extract mediated silver nanoparticles were prepared under ambient conditions which showed a narrow size distribution within the range of 10–15 nm, with average particle size of 12.7 nm. Interestingly, these nanoparticles exhibited anti-cancer activity against human breast (MCF 7, MDA MB 231) and cervical cancer (HeLa) as well as mouth epidermoid carcinoma (KB) cell lines at a concentration range of 6.25–50 μg/mL. Contrarily, they are compatible with human peripheral blood mononuclear cells and rat hepatocytes. Moreover, their efficient inhibitory effect was witnessed against Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium and Pseudomonas aeruginosa with inhibitory concentration at 5–10 μg/mL. The prepared nanoparticles were highly biocompatible and have strong potential in the development of non-toxic chemotherapy with antibacterial attributes.
Biological Control, 2016
Abstract Fungal pathogens causing the leaf spot disease of Aloe vera have been isolated from 40 r... more Abstract Fungal pathogens causing the leaf spot disease of Aloe vera have been isolated from 40 randomly selected infected leaves, collected from different locations of Birbhum and Burdwan districts of West Bengal. All of the isolates showed similar morphological characteristics and the strain VBAV007, isolated from a severely infected Aloe leaf was identified as Alternaria alternata by D1/D2 region of 28S rRNA gene sequence homology. In addition to the destruction of leaf mesophyll tissues the pathogen also decreases the antimicrobial potential of A. vera gel. The commercially available fungicide mancozeb was effective at low concentration (100 μg/ml) to control the pathogen whereas it can tolerate 1000 μg/ml or more concentrations of bavistin. Two plant growth promoting rhizobacterial strains, viz. Burkholderia cenocepacia VBC7 and Pseudomonas poae VBK1 were able to produce prominent zones of inhibition against the pathogen in dual culture overlay plates. 89.3 ± 1.22% and 81.5 ± 2.67% inhibitions of conidial germination of the pathogen were noticed in the presence of cell free supernatant of VBK1 and VBC7 respectively. Radial growth assay also suggested prominent growth inhibition of VBAV007 by biocontrol strains. They induce mycelial breakage of pathogen as evidenced by scanning electron micrographs. Greenhouse challenge experiments also suggested excellent capabilities of biocontrol agents to reduce disease severity in good measure even after exposure to high concentration (3.1 × 10 4 conidia/ml) of pathogenic spores. During in vivo field experiments 54.25 ± 3.55% disease severity was observed for untreated plants, whereas only 11.69 ± 1.25% and 15.22 ± 2.64% disease severities were noticed in plants treated with VBK1 and VBC7 respectively. Since biocontrol organisms have the potential to decrease the disease severity, they also help to maintain the good health as well as antimicrobial potential of A. vera plants.
Microbiological Research, 2016
Profuse growth of Lycpodium cernuum L. was found in phosphate deficient red lateritic soil of Wes... more Profuse growth of Lycpodium cernuum L. was found in phosphate deficient red lateritic soil of West Bengal, India. Interaction of vesicular-arbuscular mycorrhiza (VAM) with Lycopodium rhizoids were described earlier but association of PGPR with their rhizoids were not studied. Three potent phosphate solubilizing bacterial strains (P4, P9 and P10) associated with L. cernuum rhizoids were isolated and identified by 16S rDNA homologies on Ez-Taxon database as Burkholderia tropica, Burkholderia unamae and Burkholderia cepacia respectively. Day wise kinetics of phosphate solubilization against Ca3(PO4)2 suggested P4 (580.56±13.38μgml(-1)) as maximum mineral phosphate solubilizer followed by P9 (517.12±17.15μgml(-1)) and P10 (485.18±14.23μgml(-1)) at 28°C. Release of bound phosphates by isolated strains from ferric phosphate (FePO4), aluminum phosphate (AlPO4) and four different complex rock phosphates indicated their very good phosphate solubilizng efficacy. Nitrogen independent solubilizition also supports their nitrogen fixing capabilities. Inhibition of P solubilization by calcium salts and induction by EDTA suggested pH dependent chelation of metal cations by all of the isolates. Rhizoidal colonization potentials of Burkholderia spp. were confirmed by in planta experiment and also using scanning electron microscope (SEM). Increases of total phosphate content in Lycopodium plants upon soil treatment with these isolates were also recorded. In addition siderophore production on CAS agar medium, tryptophan dependent IAA production and antifungal activities against pathogenic fungi by rhizospheric isolates deep-rooted that they have definite role in nutrient mobilization for successful colonization of L. cernuum in nutrient deficient lateritic soil.
Phytomorphology: An International Journal of Plant Morphology
Benzene, petroleum-ether, chloroform and ethyl acetate extracts of Saxifraga ligulata were tested... more Benzene, petroleum-ether, chloroform and ethyl acetate extracts of Saxifraga ligulata were tested against three Gram positive bacteria viz., Bacillus subtilis, B. megaterium and Staphylococcus aureus, and five Gram negative bacteria viz., Escherichia coli, Salmonella typhimurium, Pseudomonas fluorescence, Ps. aeruginosa and Pantoea ananetis. The minimum inhibitory concentration (MIC) values of each fraction against all the bacteria were tested. Petroleum ether was found most effective, followed by ethyl acetate fraction. Both the fractions were found effective to kill all the bacteria tested, but at different doses. Benzene fraction was effective at very low concentration but was unable to produce any effect on Gram positive Staphyloccoccus aureus and Gram negative Escherichia coli. Morphology of the bacteria was severely affected when they were treated with sub lethal concentration of solvent fractions as revealed by the study of scanning electron microscopy. Also, the petroleum et...
Beneficial Microbes in Agro-Ecology, 2020
Recent Advancement in Microbial Biotechnology, 2021
Indian journal of experimental biology, 2013
Phosphorus is one of the key factors that regulate soil fertility. Its deficiencies in soil are l... more Phosphorus is one of the key factors that regulate soil fertility. Its deficiencies in soil are largely replenished by chemical fertilizers. The present study was aimed to isolate efficient phosphate solubilizing fungal strains from Eisenia fetida vermicompost. Out of total 30 fungal strains the most efficient phosphate solubilizing one was Emericella (Aspergillus) nidulans V1 (MTCC 11044), identified by custom sequencing of beta-tubulin gene and BLAST analysis. This strain solubilized 13 to 36% phosphate from four different rock phosphates. After three days of incubation of isolated culture with black Mussorie phosphate rock, the highest percentage of phosphate solubilization was 35.5 +/- 1.01 with a pH drop of 4.2 +/- 0.09. Kinetics of solubilization and acid production showed a linear relationship until day five of incubation. Interestingly, from zero to tenth day of incubation, solubility of soil phosphate increased gradually from 4.31 +/- 1.57 to 13.65 +/- 1.82 (mg kg(-1)) reco...
Honey is a traditionally used medicine for topical treatment, infected wounds and various other i... more Honey is a traditionally used medicine for topical treatment, infected wounds and various other infections. It can be effective on antibiotic resistance strains of bacteria as well (Chute et al. 2010). Antibacterial activity of honey varies with origin and processes. Honey has been used as a folklore medicine for many different purposes: as a laxative, as a natural cure for diarrhea and upset stomach, for coughs and sore throats. Honey is an ancient remedy in the Middle East, India, China and Africa for many centuries and has been used in the treatment and prevention of the common cold and various upper respiratory tract infections (Molan, 1992, Zulma and Lulat, 1989).
Rapid increase in global human population with escalating crisis for food will continue because t... more Rapid increase in global human population with escalating crisis for food will continue because the land area for agriculture is not only limited but also equivalently shrinking overtime. Therefore, the need of the time is to enhance crop productivity which eventually is leading to substantial loss in soil health due to extensive use of agrochemicals. Intensive agricultural practices (reliance on agrochemicals, conventional tillage, clean cultivation techniques, etc.) greatly deteriorate ecology and human health. Therefore, establishing an eco-friendly mechanism through significant substitution of synthetic chemical fertilizers is one of the major goals of sustainable agricultural concepts. In this context, meaningful research program on the utilization of “beneficial microorganisms” in agriculture has tremendous potential to revolutionize the agro-industry. These mutualistic beneficial microorganisms accelerate the microbial process which eventually augments the availability of nut...
Environmental Science: Nano
Nano-enabled agriculture is a vibrant research area; nonetheless, reports on effective nanofertil... more Nano-enabled agriculture is a vibrant research area; nonetheless, reports on effective nanofertilizers are rather scant.
Science of The Total Environment
Chemosphere
Brick kiln coal ashes (BKCAs) are one of the major toxic byproducts of the rapidly growing constr... more Brick kiln coal ashes (BKCAs) are one of the major toxic byproducts of the rapidly growing construction industry in developing countries. However, eco-friendly recycling avenues for BKCAs are yet to be explored. The major objectives of the present research were to evaluate the viability of vermitechnology in transforming BKCAs into valuable products, and to examine the metal detoxification potential of Eisenia fetida BKCA-based feedstocks. BKCAs were mixed in large scale with cow dung (CD) in 1:1 and 2:1 ratios, for vermicomposting and aerobic composting; performance was assessed in comparison with CD. Vermiconverted-BKCA was then used as organic fertilizer for rice grown in poorly fertile soil. Acidic nature of BKCA feedstocks was neutralized by 30-86% in the vermireactors. Total N and available P concentrations significantly increased in the vermireactors supplemented with considerable mineralization of total organic C. Exorbitantly high K and S contents were pacified to a normal range after vermicomposting. Greater improvement in microbial biomass, respiration, fungal and bacterial growth was observed under vermicomposting against aerobic composting. Consequently, urease and phosphatase activity increased by 1-4 folds in the BKCA based vermibeds. Bioavailability of toxic metals reduced by 41-74% in the vermicomposted BKCAs. High metal accumulation by the earthworms resulted in substantial reduction of pollution load in the finished product. The field experiment demonstrated that vermiconverted-BKCA could be utilized as potential organic fertilizer for rice production, soil fertility rejuvenation, and metal detoxification. Overall, the study reveals that E. fetida could be used as an efficient contender for sanitization of toxic BKCAs.
Science of The Total Environment
Spent mushroom substrate (SMS) is a recalcitrant lignocellulosic waste. Recycling of SMS through ... more Spent mushroom substrate (SMS) is a recalcitrant lignocellulosic waste. Recycling of SMS through composting has been reported; however, the process is lengthy due to its complex biochemical composition. Although vermitechnology is known for its high efficiency, it has rarely been applied to recycle SMS. In this study, the qualitative value of vermicomposted SMS mediated by three earthworm species (i.e., Eisenia fetida, Eudrilus eugeniae, and Perionyx excavatus) was evaluated on the basis of nutrient availability, microbial activity, phospholipid fatty acid (PLFA) profiles, and seed germination assays. Degradation profiles of the lignocellulosic substrate in the vermireactors were assessed by monitoring the changes in crystallinity and distribution of functional groups using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy, respectively. Total organic carbon decreased by 1.4-3.5 folds with approximately 2.1-2.4 folds increase in nitrogen and phosphorus availability in all vermibeds. Interestingly, pH declined in the Eisenia and Eudrilus systems but increased in the Perionyx-vermibeds. XRD-derived crystallinity index was reduced significantly by 1.37 folds in Perionyx-vermicompost with concurrent microbial enrichment. Further, profuse abundance of vital functional groups (CO, NH, and OH) was clearly observed in the vermicompost with Perionyx followed by that with Eisenia. Moreover, PLFA illustrated significant variations in fatty acid distributions and microbial communities of the three vermicomposting systems. The seed germination assay showed that the germination index and relative root-shoot vigor of Perionyx-vermicompost treated seeds were 1.05-1.30 times greater than those of Eisenia and Eudrilus vermicompost treated ones. The results suggest that SMS degradability was affected by the growth of a healthy microbial community through vermicomposting.
NASS Journal of Agricultural Sciences
Silver nanoparticles (AgNP) synthesized from It influenced the inherent soil properties like bulk... more Silver nanoparticles (AgNP) synthesized from It influenced the inherent soil properties like bulk density (BD), water holding capacity (WHC), available N, P, K, urease, phosphatase activity and TOC. The apparent increment WHC, N, P, K, urease, and phosphatase in soil were observed whereas reduction of BD was noticed. Due to application of nanosolutions the pH of the soil shifted towards neutrality from 0 to 60 days. Moreover, they also did not have any toxicity upon plant as well as earthworm ecosystem.
Annals of Agrarian Science
Abstract Three potent strains of lactic acid bacteria (LAB) with bacteriocin producing abilities ... more Abstract Three potent strains of lactic acid bacteria (LAB) with bacteriocin producing abilities have been isolated from homemade buttermilk. They can produce proteinaceous bacteriocins in the medium which are resistant to heat (121 °C for 15 min) and can tolerate range of pH from 3.0 to 11.0. They were found to be Gram positive, non-motile, non-endospore forming, coccoid structures. The strains LABW1 and LABW3 were present in chains while LABW4 were present singly or in pairs. By considering the 16S rDNA sequence homologies and phylogenetic analysis LABW1 and LABW3 were identified as Lactococcus lactis subsp. hordniae where as LABW4 was identified as Lactococcus lactis subsp. lactis. Maximum extracellular bacteriocin production by the isolates takes place in MRS medium (pH 5.0–7.0) at 28 °C and it showed strong correlation with bacterial growth. They started producing bacteriocin at early exponential phase (400 AU/ml) and reached its peak at the early stationary phase (12800 AU/ml for LABW1 and LABW3 and 25600 AU/ml for LABW4) which remain unchanged up to late stationary phase. The bacteriocin of the isolates had an antibacterial spectrum both against Gram positive as well as Gram negative pathogenic bacterial strains. The inhibition of Gram negative bacteria by bacteriocin of LAB is an unusual phenomenon. It exhibits bacteriocidal action on Staphylococcus aureus MTCC96 and Pseudomonas aeruginosa MTCC741. Prominent morphological aberrations, cell shrinkages and pore formations on cell wall of pathogenic bacterial cells upon bacteriocin treatment as evidenced from scanning electron microscope (SEM).
Asian Journal of Pharmaceutical and Clinical Research
Objectives: Endophytic fungi are considered as an important source of bioactive metabolites. The ... more Objectives: Endophytic fungi are considered as an important source of bioactive metabolites. The present study focused on the isolation of potent endophytic fungal strains from well-known medicinal plant Rauvolfia serpentina L. Benth. having biological activities.Materials & Methods: Fungal endophytes were isolated from aerial parts of the plant and the potent strain was selected on the basis of antibacterial activities of cell-free supernatant (CFS). Ethyl acetate (EA) extraction of CFS was done and mode of action of EA fraction was checked against pathogenic bacteria. EA fraction was also analyzed by thin-layer chromatography (TLC). In addition, antioxidant activity was checked by 1,1-Diphenyl- 2-picrylhydrazyl-free radical scavenging assay and anticancer activity was checked against breast cancer cell line MCF-7 by MTT assay.Results: Among the different endophytic fungal isolates, CFS of Alternaria sp. RL4 produced prominent zones of inhibition against numbers of Gram-positive pa...
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences
PLOS ONE
Provide an accurate summary of the background, research objectives, including details of the spec... more Provide an accurate summary of the background, research objectives, including details of the species or strain of animal used, key methods, principal findings and conclusions of the study.
Journal of Nanoscience and Nanotechnology
Silver nanoparticles contribute a giant share to the realm of modern nanobiotechnology. Their uti... more Silver nanoparticles contribute a giant share to the realm of modern nanobiotechnology. Their utility as antimicrobial agents is also well documented. Green synthesis of nanoparticle has several advantages over its chemical synthesis. In the present study, Thuja occidentalis leaf extract mediated silver nanoparticles were prepared without using a stabilizing agent and tested for their anticancer and anti-microbial activity. Thuja occidentalis leaf extract mediated silver nanoparticles were prepared under ambient conditions which showed a narrow size distribution within the range of 10–15 nm, with average particle size of 12.7 nm. Interestingly, these nanoparticles exhibited anti-cancer activity against human breast (MCF 7, MDA MB 231) and cervical cancer (HeLa) as well as mouth epidermoid carcinoma (KB) cell lines at a concentration range of 6.25–50 μg/mL. Contrarily, they are compatible with human peripheral blood mononuclear cells and rat hepatocytes. Moreover, their efficient inhibitory effect was witnessed against Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium and Pseudomonas aeruginosa with inhibitory concentration at 5–10 μg/mL. The prepared nanoparticles were highly biocompatible and have strong potential in the development of non-toxic chemotherapy with antibacterial attributes.
Biological Control, 2016
Abstract Fungal pathogens causing the leaf spot disease of Aloe vera have been isolated from 40 r... more Abstract Fungal pathogens causing the leaf spot disease of Aloe vera have been isolated from 40 randomly selected infected leaves, collected from different locations of Birbhum and Burdwan districts of West Bengal. All of the isolates showed similar morphological characteristics and the strain VBAV007, isolated from a severely infected Aloe leaf was identified as Alternaria alternata by D1/D2 region of 28S rRNA gene sequence homology. In addition to the destruction of leaf mesophyll tissues the pathogen also decreases the antimicrobial potential of A. vera gel. The commercially available fungicide mancozeb was effective at low concentration (100 μg/ml) to control the pathogen whereas it can tolerate 1000 μg/ml or more concentrations of bavistin. Two plant growth promoting rhizobacterial strains, viz. Burkholderia cenocepacia VBC7 and Pseudomonas poae VBK1 were able to produce prominent zones of inhibition against the pathogen in dual culture overlay plates. 89.3 ± 1.22% and 81.5 ± 2.67% inhibitions of conidial germination of the pathogen were noticed in the presence of cell free supernatant of VBK1 and VBC7 respectively. Radial growth assay also suggested prominent growth inhibition of VBAV007 by biocontrol strains. They induce mycelial breakage of pathogen as evidenced by scanning electron micrographs. Greenhouse challenge experiments also suggested excellent capabilities of biocontrol agents to reduce disease severity in good measure even after exposure to high concentration (3.1 × 10 4 conidia/ml) of pathogenic spores. During in vivo field experiments 54.25 ± 3.55% disease severity was observed for untreated plants, whereas only 11.69 ± 1.25% and 15.22 ± 2.64% disease severities were noticed in plants treated with VBK1 and VBC7 respectively. Since biocontrol organisms have the potential to decrease the disease severity, they also help to maintain the good health as well as antimicrobial potential of A. vera plants.
Microbiological Research, 2016
Profuse growth of Lycpodium cernuum L. was found in phosphate deficient red lateritic soil of Wes... more Profuse growth of Lycpodium cernuum L. was found in phosphate deficient red lateritic soil of West Bengal, India. Interaction of vesicular-arbuscular mycorrhiza (VAM) with Lycopodium rhizoids were described earlier but association of PGPR with their rhizoids were not studied. Three potent phosphate solubilizing bacterial strains (P4, P9 and P10) associated with L. cernuum rhizoids were isolated and identified by 16S rDNA homologies on Ez-Taxon database as Burkholderia tropica, Burkholderia unamae and Burkholderia cepacia respectively. Day wise kinetics of phosphate solubilization against Ca3(PO4)2 suggested P4 (580.56±13.38μgml(-1)) as maximum mineral phosphate solubilizer followed by P9 (517.12±17.15μgml(-1)) and P10 (485.18±14.23μgml(-1)) at 28°C. Release of bound phosphates by isolated strains from ferric phosphate (FePO4), aluminum phosphate (AlPO4) and four different complex rock phosphates indicated their very good phosphate solubilizng efficacy. Nitrogen independent solubilizition also supports their nitrogen fixing capabilities. Inhibition of P solubilization by calcium salts and induction by EDTA suggested pH dependent chelation of metal cations by all of the isolates. Rhizoidal colonization potentials of Burkholderia spp. were confirmed by in planta experiment and also using scanning electron microscope (SEM). Increases of total phosphate content in Lycopodium plants upon soil treatment with these isolates were also recorded. In addition siderophore production on CAS agar medium, tryptophan dependent IAA production and antifungal activities against pathogenic fungi by rhizospheric isolates deep-rooted that they have definite role in nutrient mobilization for successful colonization of L. cernuum in nutrient deficient lateritic soil.
Phytomorphology: An International Journal of Plant Morphology
Benzene, petroleum-ether, chloroform and ethyl acetate extracts of Saxifraga ligulata were tested... more Benzene, petroleum-ether, chloroform and ethyl acetate extracts of Saxifraga ligulata were tested against three Gram positive bacteria viz., Bacillus subtilis, B. megaterium and Staphylococcus aureus, and five Gram negative bacteria viz., Escherichia coli, Salmonella typhimurium, Pseudomonas fluorescence, Ps. aeruginosa and Pantoea ananetis. The minimum inhibitory concentration (MIC) values of each fraction against all the bacteria were tested. Petroleum ether was found most effective, followed by ethyl acetate fraction. Both the fractions were found effective to kill all the bacteria tested, but at different doses. Benzene fraction was effective at very low concentration but was unable to produce any effect on Gram positive Staphyloccoccus aureus and Gram negative Escherichia coli. Morphology of the bacteria was severely affected when they were treated with sub lethal concentration of solvent fractions as revealed by the study of scanning electron microscopy. Also, the petroleum et...