Abstract The present status of knowledge on the physiology and biochemistry of Xenorhabdus is sum... more Abstract The present status of knowledge on the physiology and biochemistry of Xenorhabdus is summarized with particular emphasis on growth and secondary metabolite production. The growth and activity of Xenorhabdus within the insect host is also ...
Natural drugs play important and vital role in the modern medicine. It is usually used to cure so... more Natural drugs play important and vital role in the modern medicine. It is usually used to cure some diseases which may not be treated by conventional medicine. Drugs from the plants are easily available less expensive, safe and efficient and rarely have side effects. The alkaloids, tannins, flavanoids and phenol compounds play a major role in preventing various chronic diseases by a definite physiological action on the human body like anticancer, antimicrobial, antioxidant and anti-diabetic activities. The aim of the present study was to evaluate the phytochemical analysis and antioxidant activity of ethanolic extract of Flowers of Tagetes Erecta and rhizome of Zingiber Officinale. Phytochemical screening was carried out for ethanolic extract revealed the presence of various bioactive components include alkaloids, carbohydrates, proteins and saponins. Antioxidant activity was assayed by the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, nitroblue tetrazolium (NBT) and ferric reducing power (FRAP). In all the assays, stem extract exhibited stronger antioxidant activity than that of flowers. The present results showed antibacterial and antioxidant activity of the extracts was found to be positively associated with the total phenolic and flavonoid content of the extracts.
In this study, Doronicum hookeri Hook f. roots were extracted with two solvents of different pola... more In this study, Doronicum hookeri Hook f. roots were extracted with two solvents of different polarity and evaluated for their in vitro antioxidant activities. Of the two extracts, methanolic extract possessed higher phenolic content and thus higher free radical scavenging and reducing activities. In DPPH (2,2diphenyl-1-picryhydrazy) radical scavenging assay, methanolic extract showed scavenging similar to the standard BHT(butylated hydroxytoluene) (~85%) at concentration 0.5 mg/ml. Methanolic extract also exhibited more than 90% inhibition to ABTS radicals at concentration above 0.3 mg/ml. Reducing power activity of methanolic extract was also higher than dichloromethane extract. Dichloromethane extract was however rich in flavonoids and showed considerable metal chelating (78.684±0.659% at 0.5 mg/ml), nitric oxide (52.232±0.934% at 0.15 mg/ml) and superoxide radical (59.882±0.772% at 0.5 mg/ml) scavenging activities.
Streptomyces spp. are soil microorganisms that are important in decomposition of organic matter i... more Streptomyces spp. are soil microorganisms that are important in decomposition of organic matter in soil. Genetic exchange among Streptomyces species is known to occur readily both on agar and in soil in the laboratory and evidence indicates that transfer of genes from released recombinant Streptomyces to native soil streptomycetes also occurs. Minimal data are available on the environmental effects of such gene transfer.
Heterotrophic bacteria, yeasts, fungi, plants, and animal breath were investigated as possible so... more Heterotrophic bacteria, yeasts, fungi, plants, and animal breath were investigated as possible sources of N(2)O. Microbes found to produce N(2)O from NO(3) but not consume it were: (i) all of the nitrate-respiring bacteria examined, including strains of Escherichia, Serratia, Klebsiella, Enterobacter, Erwinia, and Bacillus; (ii) one of the assimilatory nitrate-reducing bacteria examined, Azotobacter vinelandii, but not Azotobacter macrocytogenes or Acinetobacter sp.; and (iii) some but not all of the assimilatory nitrate-reducing yeasts and fungi, including strains of Hansenula, Rhodotorula, Aspergillus, Alternaria, and Fusarium. The NO(3)-reducing obligate anaerobe Clostridium KDHS2 did not produce N(2)O. Production of N(2)O occurred only in stationary phase. The nitrate-respiring bacteria produced much more N(2)O than the other organisms, with yields of N(2)O ranging from 3 to 36% of 3.5 mM NO(3). Production of N(2)O was apparently not regulated by ammonium and was not restricted ...
Azospirillum lipoferum RG6xx was grown under conditions similar to those resulting in encystment ... more Azospirillum lipoferum RG6xx was grown under conditions similar to those resulting in encystment of Azotobacter spp. A. lipoferum produced cells of uniform shape when grown on nitrogen-free 0-hydroxybutyrate agar. Cells accumulated poly-jI-hydroxybutyrate and often grew as chains or filaments that eventually lost motility and formed capsules. Within 1 week, vegetative A. lipoferum inocula were converted into microflocs arising from filaments or chains. Cells within microflocs were pleomorphic, contained much poly-I8hydroxybutyrate, and were encapsulated. Some cells had a cystlike morphology. Up to 57% of the dry weight of encapsulated flocs was poly-jI-hydroxybutyrate, whereas vegetative cells grown in broth with combined nitrogen had only 3% of their dry weight as poly-j-hydroxybutyrate. Neither encapsulated cells in flocs nor nonencapsulated vegetative cells were significantly desiccation resistant. Under starvation conditions (9 days) only 25% of encapsulated cells remained viable, whereas vegetative cells multiplied severalfold. In short-term germination experiments with encapsulated flocs, nitrate, ammonium, and soil extract promoted formation of motile vegetative cells. Most cells in treatments lacking combined nitrogen eventually depleted their visible poly-jI-hydroxybutyrate reserves without germinating. The remaining cells retained the reserve polymer and underwent size reduction.
A recombinant actinomycete, Streptomyces lividans TK23.1, expressing a pIJ702-encoded extracellul... more A recombinant actinomycete, Streptomyces lividans TK23.1, expressing a pIJ702-encoded extracellular lignin peroxidase gene cloned from the chromosome of Streptomyces viridosporus T7A, was released into soil in flask- and microcosm-scale studies to determine its effects on humification and elemental cycling and on the numbers, types, and activities of microorganisms native to the soil. Strain TK23.1 had been shown previously to transiently increase the rate of organic carbon mineralization in soil via an effect that was recombinant specific and particularly significant in nonsterile soils already possessing an active microflora. The results of this study confirmed the previous findings and showed that additional effects were measurable upon release of the recombinant strain TK23.1 into unamended soil and into soil amended with lignocellulose. In addition to a transient enhancement of carbon mineralization, the recombinant affected soil pH, the rate of incorporation of carbon into soi...
Streptomyces spp. are soil microorganisms that are important in decomposition of organic matter i... more Streptomyces spp. are soil microorganisms that are important in decomposition of organic matter in soil. Genetic exchange among Streptomyces species is known to occur readily both on agar and in soil in the laboratory and evidence indicates that transfer of genes from released recombinant Streptomyces to native soil streptomycetes also occurs. Minimal data are available on the environmental effects of such gene transfer.
h i g h l i g h t s • Chemical properties of high temperature biochars were fairly consistent. • ... more h i g h l i g h t s • Chemical properties of high temperature biochars were fairly consistent. • Biochars showed negative priming effect on mineralization of carbon and nitrogen. • Biochars showed negative impact on microbial and enzymatic activity.
Environmental science and pollution research international, Jan 5, 2014
Knowledge of how biochar impacts soil denitrification kinetics as well as the mechanisms of inter... more Knowledge of how biochar impacts soil denitrification kinetics as well as the mechanisms of interactions is essential in order to better predict the nitrous oxide (N2O) mitigation capacity of biochar additions. This study had multiple experiments in which the effect of three biochar materials produced from corn stover (Zea mays L.), ponderosa pine wood residue (Pinus ponderosa Douglas ex Lawson and C. Lawson), switchgrass (Panicum virgatum L.), and their corresponding biomass materials (corn stover, ponderosa pine wood residue, and switchgrass) on cumulative N2O emissions and total denitrification in soils from two different landscape positions (crest and footslope) were studied under varying water-filled pore space (40, 70, and 90 % WFPS). Cumulative N2O emissions were reduced by 30 to 70 % in both crest and footslope soils. The effect of biochars and biomass treatments on cumulative N2O emissions and total denitrification were only observed at ≥40 % WFPS. The denitrification enzym...
In this document, we describe the wealth of science opportunities and capabilities of LBNE, the L... more In this document, we describe the wealth of science opportunities and capabilities of LBNE, the Long-Baseline Neutrino Experiment. LBNE has been developed to provide a unique and compelling program for the exploration of key questions at the forefront of particle physics. Chief among the discovery opportunities are observation of CP symmetry violation in neutrino mixing, resolution of the neutrino mass hierarchy, determination of maximal or near-maximal mixing in neutrinos, searches for nucleon decay signatures, and detailed studies of neutrino bursts from galactic supernovae. To fulfill these and other goals as a world-class facility, LBNE is conceived around four central components: (1) a new, intense wide-band neutrino source at Fermilab, (2) a fine-grained `near' neutrino detector just downstream of the source, (3) the Sanford Underground Research Facility (SURF) in Lead, South Dakota at an optimal distance (~1300 km) from the neutrino source, and (4) a massive liquid argon ...
Thesis (M.S.)--Michigan State University. Dept. of Crop and Soil Sciences, 1981. Includes bibliog... more Thesis (M.S.)--Michigan State University. Dept. of Crop and Soil Sciences, 1981. Includes bibliographies.
The degree of resistance to water penetration of diverse water repellent soils was found to be co... more The degree of resistance to water penetration of diverse water repellent soils was found to be controlled by their moisture states. Repellency was found to increase sharply when samples were incubated at 100% relative humidity and to decline when wetted or when incubated ...
Clostridium diffıcile est une bactérie entéropathogènes dont les facteurs de virulence majeurs so... more Clostridium diffıcile est une bactérie entéropathogènes dont les facteurs de virulence majeurs sont les toxines A et B. Cependant, d'autres structures ont été impliquées dans la colonisation du tractus digestif par cette bactérie, première étape de la pathogenèse. Outre des facteurs d'adhérence, C. diffıcile présente une activité protéolytique de surface qui pourrait jouer un rôle dans sa physiopathologie. L'objectif de ce travail était d'étudier une protéine dénommée Cwp84, qui présente des homologies significatives avec de nombreuses cystéines protéases. La partie catalytique de la protéine a été purifiée sous forme recombinante, après clonage du gène dans le vecteur d'expression pGEX-6P-1, en fusion avec le gène codant pour la glutathion-S-transférase. La fraction ainsi purifiée présente une activité protéolytique sur gélatine et sur BAPNA, substrat synthétique de protéase, mais n'a pas d'activité sur azocoll, ce qui témoigne d'une spécificité d'action étroite. Le profil d'inhibition de cette enzyme confirme son appartenance à la famille des cystéines protéases. Cwp84 pourrait intervenir soit dans la dégradation de certaines molécules spécifiques des tissus de l'hôte, soit dans la maturation de certaines protéines de surface de C. diffıcile.
A lignin peroxidase gene was cloned from Streptomyces viridosporus T7A into Streptomyces lividans... more A lignin peroxidase gene was cloned from Streptomyces viridosporus T7A into Streptomyces lividans TK64 in plasmid pIJ702. BglII-digested genomic DNA (4-10 kb) of S. viridosporus was shotgun-cloned into S. lioidans after insertion into the melanin (mel +) gene of pIJ702. Transformants expressing pIJ702 with insert DNA were selected based upon the appearance of thiostrepton resistant (tsrr)/melcolonies on regeneration medium. Lignin peroxidase-expressing clones were isolated from this population by screening of transformants on a tsr-poly B-411 dye agar medium. In the presence of H202 excreted by S. lividans, colonies of lignin peroxidase-expressing clones decolorized the dye. Among 1000 transformants screened, 2 dye-decolorizing clones were found. One, pIJ702/TK64.1 (TK64.1), was further characterized. TK64.1 expressed significant extracellular 2,4-dichlorophenol (2,4-DCP) peroxidase activity (= assay for S. viridosporus lignin peroxidase). Under the cultural conditions employed, plasmidless S. lividans TK64 had a low background level of 2,4-DCP oxidizing activity. TK64.1 excreted an extracellular peroxidase not observed in S. lividans TK64, but similar to S. viridosporus lignin peroxidase ALip-P3, as shown by activity stain assays on nondenaturing polyacrylamide gels. The gene was located on a 4 kb fragment of S. viridosporus genomic DNA. When peroxidase-encoding plasmid, pIJ702.LP, was purified and used to
Abstract The present status of knowledge on the physiology and biochemistry of Xenorhabdus is sum... more Abstract The present status of knowledge on the physiology and biochemistry of Xenorhabdus is summarized with particular emphasis on growth and secondary metabolite production. The growth and activity of Xenorhabdus within the insect host is also ...
Natural drugs play important and vital role in the modern medicine. It is usually used to cure so... more Natural drugs play important and vital role in the modern medicine. It is usually used to cure some diseases which may not be treated by conventional medicine. Drugs from the plants are easily available less expensive, safe and efficient and rarely have side effects. The alkaloids, tannins, flavanoids and phenol compounds play a major role in preventing various chronic diseases by a definite physiological action on the human body like anticancer, antimicrobial, antioxidant and anti-diabetic activities. The aim of the present study was to evaluate the phytochemical analysis and antioxidant activity of ethanolic extract of Flowers of Tagetes Erecta and rhizome of Zingiber Officinale. Phytochemical screening was carried out for ethanolic extract revealed the presence of various bioactive components include alkaloids, carbohydrates, proteins and saponins. Antioxidant activity was assayed by the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, nitroblue tetrazolium (NBT) and ferric reducing power (FRAP). In all the assays, stem extract exhibited stronger antioxidant activity than that of flowers. The present results showed antibacterial and antioxidant activity of the extracts was found to be positively associated with the total phenolic and flavonoid content of the extracts.
In this study, Doronicum hookeri Hook f. roots were extracted with two solvents of different pola... more In this study, Doronicum hookeri Hook f. roots were extracted with two solvents of different polarity and evaluated for their in vitro antioxidant activities. Of the two extracts, methanolic extract possessed higher phenolic content and thus higher free radical scavenging and reducing activities. In DPPH (2,2diphenyl-1-picryhydrazy) radical scavenging assay, methanolic extract showed scavenging similar to the standard BHT(butylated hydroxytoluene) (~85%) at concentration 0.5 mg/ml. Methanolic extract also exhibited more than 90% inhibition to ABTS radicals at concentration above 0.3 mg/ml. Reducing power activity of methanolic extract was also higher than dichloromethane extract. Dichloromethane extract was however rich in flavonoids and showed considerable metal chelating (78.684±0.659% at 0.5 mg/ml), nitric oxide (52.232±0.934% at 0.15 mg/ml) and superoxide radical (59.882±0.772% at 0.5 mg/ml) scavenging activities.
Streptomyces spp. are soil microorganisms that are important in decomposition of organic matter i... more Streptomyces spp. are soil microorganisms that are important in decomposition of organic matter in soil. Genetic exchange among Streptomyces species is known to occur readily both on agar and in soil in the laboratory and evidence indicates that transfer of genes from released recombinant Streptomyces to native soil streptomycetes also occurs. Minimal data are available on the environmental effects of such gene transfer.
Heterotrophic bacteria, yeasts, fungi, plants, and animal breath were investigated as possible so... more Heterotrophic bacteria, yeasts, fungi, plants, and animal breath were investigated as possible sources of N(2)O. Microbes found to produce N(2)O from NO(3) but not consume it were: (i) all of the nitrate-respiring bacteria examined, including strains of Escherichia, Serratia, Klebsiella, Enterobacter, Erwinia, and Bacillus; (ii) one of the assimilatory nitrate-reducing bacteria examined, Azotobacter vinelandii, but not Azotobacter macrocytogenes or Acinetobacter sp.; and (iii) some but not all of the assimilatory nitrate-reducing yeasts and fungi, including strains of Hansenula, Rhodotorula, Aspergillus, Alternaria, and Fusarium. The NO(3)-reducing obligate anaerobe Clostridium KDHS2 did not produce N(2)O. Production of N(2)O occurred only in stationary phase. The nitrate-respiring bacteria produced much more N(2)O than the other organisms, with yields of N(2)O ranging from 3 to 36% of 3.5 mM NO(3). Production of N(2)O was apparently not regulated by ammonium and was not restricted ...
Azospirillum lipoferum RG6xx was grown under conditions similar to those resulting in encystment ... more Azospirillum lipoferum RG6xx was grown under conditions similar to those resulting in encystment of Azotobacter spp. A. lipoferum produced cells of uniform shape when grown on nitrogen-free 0-hydroxybutyrate agar. Cells accumulated poly-jI-hydroxybutyrate and often grew as chains or filaments that eventually lost motility and formed capsules. Within 1 week, vegetative A. lipoferum inocula were converted into microflocs arising from filaments or chains. Cells within microflocs were pleomorphic, contained much poly-I8hydroxybutyrate, and were encapsulated. Some cells had a cystlike morphology. Up to 57% of the dry weight of encapsulated flocs was poly-jI-hydroxybutyrate, whereas vegetative cells grown in broth with combined nitrogen had only 3% of their dry weight as poly-j-hydroxybutyrate. Neither encapsulated cells in flocs nor nonencapsulated vegetative cells were significantly desiccation resistant. Under starvation conditions (9 days) only 25% of encapsulated cells remained viable, whereas vegetative cells multiplied severalfold. In short-term germination experiments with encapsulated flocs, nitrate, ammonium, and soil extract promoted formation of motile vegetative cells. Most cells in treatments lacking combined nitrogen eventually depleted their visible poly-jI-hydroxybutyrate reserves without germinating. The remaining cells retained the reserve polymer and underwent size reduction.
A recombinant actinomycete, Streptomyces lividans TK23.1, expressing a pIJ702-encoded extracellul... more A recombinant actinomycete, Streptomyces lividans TK23.1, expressing a pIJ702-encoded extracellular lignin peroxidase gene cloned from the chromosome of Streptomyces viridosporus T7A, was released into soil in flask- and microcosm-scale studies to determine its effects on humification and elemental cycling and on the numbers, types, and activities of microorganisms native to the soil. Strain TK23.1 had been shown previously to transiently increase the rate of organic carbon mineralization in soil via an effect that was recombinant specific and particularly significant in nonsterile soils already possessing an active microflora. The results of this study confirmed the previous findings and showed that additional effects were measurable upon release of the recombinant strain TK23.1 into unamended soil and into soil amended with lignocellulose. In addition to a transient enhancement of carbon mineralization, the recombinant affected soil pH, the rate of incorporation of carbon into soi...
Streptomyces spp. are soil microorganisms that are important in decomposition of organic matter i... more Streptomyces spp. are soil microorganisms that are important in decomposition of organic matter in soil. Genetic exchange among Streptomyces species is known to occur readily both on agar and in soil in the laboratory and evidence indicates that transfer of genes from released recombinant Streptomyces to native soil streptomycetes also occurs. Minimal data are available on the environmental effects of such gene transfer.
h i g h l i g h t s • Chemical properties of high temperature biochars were fairly consistent. • ... more h i g h l i g h t s • Chemical properties of high temperature biochars were fairly consistent. • Biochars showed negative priming effect on mineralization of carbon and nitrogen. • Biochars showed negative impact on microbial and enzymatic activity.
Environmental science and pollution research international, Jan 5, 2014
Knowledge of how biochar impacts soil denitrification kinetics as well as the mechanisms of inter... more Knowledge of how biochar impacts soil denitrification kinetics as well as the mechanisms of interactions is essential in order to better predict the nitrous oxide (N2O) mitigation capacity of biochar additions. This study had multiple experiments in which the effect of three biochar materials produced from corn stover (Zea mays L.), ponderosa pine wood residue (Pinus ponderosa Douglas ex Lawson and C. Lawson), switchgrass (Panicum virgatum L.), and their corresponding biomass materials (corn stover, ponderosa pine wood residue, and switchgrass) on cumulative N2O emissions and total denitrification in soils from two different landscape positions (crest and footslope) were studied under varying water-filled pore space (40, 70, and 90 % WFPS). Cumulative N2O emissions were reduced by 30 to 70 % in both crest and footslope soils. The effect of biochars and biomass treatments on cumulative N2O emissions and total denitrification were only observed at ≥40 % WFPS. The denitrification enzym...
In this document, we describe the wealth of science opportunities and capabilities of LBNE, the L... more In this document, we describe the wealth of science opportunities and capabilities of LBNE, the Long-Baseline Neutrino Experiment. LBNE has been developed to provide a unique and compelling program for the exploration of key questions at the forefront of particle physics. Chief among the discovery opportunities are observation of CP symmetry violation in neutrino mixing, resolution of the neutrino mass hierarchy, determination of maximal or near-maximal mixing in neutrinos, searches for nucleon decay signatures, and detailed studies of neutrino bursts from galactic supernovae. To fulfill these and other goals as a world-class facility, LBNE is conceived around four central components: (1) a new, intense wide-band neutrino source at Fermilab, (2) a fine-grained `near' neutrino detector just downstream of the source, (3) the Sanford Underground Research Facility (SURF) in Lead, South Dakota at an optimal distance (~1300 km) from the neutrino source, and (4) a massive liquid argon ...
Thesis (M.S.)--Michigan State University. Dept. of Crop and Soil Sciences, 1981. Includes bibliog... more Thesis (M.S.)--Michigan State University. Dept. of Crop and Soil Sciences, 1981. Includes bibliographies.
The degree of resistance to water penetration of diverse water repellent soils was found to be co... more The degree of resistance to water penetration of diverse water repellent soils was found to be controlled by their moisture states. Repellency was found to increase sharply when samples were incubated at 100% relative humidity and to decline when wetted or when incubated ...
Clostridium diffıcile est une bactérie entéropathogènes dont les facteurs de virulence majeurs so... more Clostridium diffıcile est une bactérie entéropathogènes dont les facteurs de virulence majeurs sont les toxines A et B. Cependant, d'autres structures ont été impliquées dans la colonisation du tractus digestif par cette bactérie, première étape de la pathogenèse. Outre des facteurs d'adhérence, C. diffıcile présente une activité protéolytique de surface qui pourrait jouer un rôle dans sa physiopathologie. L'objectif de ce travail était d'étudier une protéine dénommée Cwp84, qui présente des homologies significatives avec de nombreuses cystéines protéases. La partie catalytique de la protéine a été purifiée sous forme recombinante, après clonage du gène dans le vecteur d'expression pGEX-6P-1, en fusion avec le gène codant pour la glutathion-S-transférase. La fraction ainsi purifiée présente une activité protéolytique sur gélatine et sur BAPNA, substrat synthétique de protéase, mais n'a pas d'activité sur azocoll, ce qui témoigne d'une spécificité d'action étroite. Le profil d'inhibition de cette enzyme confirme son appartenance à la famille des cystéines protéases. Cwp84 pourrait intervenir soit dans la dégradation de certaines molécules spécifiques des tissus de l'hôte, soit dans la maturation de certaines protéines de surface de C. diffıcile.
A lignin peroxidase gene was cloned from Streptomyces viridosporus T7A into Streptomyces lividans... more A lignin peroxidase gene was cloned from Streptomyces viridosporus T7A into Streptomyces lividans TK64 in plasmid pIJ702. BglII-digested genomic DNA (4-10 kb) of S. viridosporus was shotgun-cloned into S. lioidans after insertion into the melanin (mel +) gene of pIJ702. Transformants expressing pIJ702 with insert DNA were selected based upon the appearance of thiostrepton resistant (tsrr)/melcolonies on regeneration medium. Lignin peroxidase-expressing clones were isolated from this population by screening of transformants on a tsr-poly B-411 dye agar medium. In the presence of H202 excreted by S. lividans, colonies of lignin peroxidase-expressing clones decolorized the dye. Among 1000 transformants screened, 2 dye-decolorizing clones were found. One, pIJ702/TK64.1 (TK64.1), was further characterized. TK64.1 expressed significant extracellular 2,4-dichlorophenol (2,4-DCP) peroxidase activity (= assay for S. viridosporus lignin peroxidase). Under the cultural conditions employed, plasmidless S. lividans TK64 had a low background level of 2,4-DCP oxidizing activity. TK64.1 excreted an extracellular peroxidase not observed in S. lividans TK64, but similar to S. viridosporus lignin peroxidase ALip-P3, as shown by activity stain assays on nondenaturing polyacrylamide gels. The gene was located on a 4 kb fragment of S. viridosporus genomic DNA. When peroxidase-encoding plasmid, pIJ702.LP, was purified and used to
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