Induction of sporangia in Phytophthora cinnamomi by a substance from bacteria and soil

1971 ◽  
Vol 17 (12) ◽  
pp. 1517-1523 ◽  
Author(s):  
William A. Ayers
Keyword(s):  
Thin Layer ◽  
Active Substance ◽  
Phytophthora Cinnamomi ◽  
Optimum Concentration ◽  
Mineral Salts ◽  
Reproductive Structures ◽  
Heat Stable ◽  
Mixed Populations ◽  
Optimum Concentration Range ◽  
Acetone Extracts

Production of sporangia of Phytophthora cinnamomi on agar–mycelial disks in a mineral salts solution was induced by extracts of a soil pseudomonad. Acetone extracts of soil and of mixed populations of microorganisms from soil solution also stimulated the formation of these asexual reproductive structures. Active extracts stimulated sporangium production in aqueous dilutions as high as 10−9. Some extracts of the bacterium were less active at dilutions above or below a certain optimum concentration range. The unidentified, active substance was characterized as a nonvolatile, polar, heat-stable compound that is soluble in water and several organic solvents. Salts of Ca, Mg, K, and Fe in the suspending medium favored a limited production of sporangia in the absence of active substance, and abundant sporangia in its presence. Ca2+was essential for maximum response. The substance was detected by bioassay on paper and thin-layer chromatograms, and it was obtained partially purified.

A Study on UV Filter Chemicals from Annex VII of European Union Directive 76/768/EEC, in the In Vitro 3T3 NRU Phototoxicity Test

1998 ◽  
Vol 26 (5) ◽  
pp. 679-708 ◽  
Author(s):  
Horst Spielmann ◽  
Michael Balls ◽  
Jack Dupuis ◽  
Wolfgang J. W. Pape ◽  
Odile de Silva ◽  
...  
Keyword(s):  
Neutral Red ◽  
Optimum Concentration ◽  
Alternative Methods ◽  
Uv Filter ◽  
Eu Directive ◽  
Optimum Concentration Range ◽  
The Impact ◽  
Positive Results

In 1996, the Scientific Committee on Cosmetology of DGXXIV of the European Commission asked the European Centre for the Validation of Alternative Methods to test eight UV filter chemicals from the 1995 edition of Annex VII of Directive 76/768/EEC in a blind trial in the in vitro 3T3 cell neutral red uptake phototoxicity (3T3 NRU PT) test, which had been scientifically validated between 1992 and 1996. Since all the UV filter chemicals on the positive list of EU Directive 76/768/EEC have been shown not to be phototoxic in vivo in humans under use conditions, only negative effects would be expected in the 3T3 NRU PT test. To balance the number of positive and negative chemicals, ten phototoxic and ten non-phototoxic chemicals were tested under blind conditions in four laboratories. Moreover, to assess the optimum concentration range for testing, information was provided on appropriate solvents and on the solubility of the coded chemicals. In this study, the phototoxic potential of test chemicals was evaluated in a prediction model in which either the Photoirritation Factor (PIF) or the Mean Photo Effect (MPE) were determined. The results obtained with both PIF and MPE were highly reproducible in the four laboratories, and the correlation between in vitro and in vivo data was almost perfect. All the phototoxic test chemicals provided a positive result at concentrations of 1μg/ml, while nine of the ten non-phototoxic chemicals gave clear negative results, even at the highest test concentrations. One of the UV filter chemicals gave positive results in three of the four laboratories only at concentrations greater than 100μg/ml; the other laboratory correctly identified all 20 of the test chemicals. An analysis of the impact that exposure concentrations had on the performance of the test revealed that the optimum concentration range in the 3T3 NRU PT test for determining the phototoxic potential of chemicals is between 0.1μg/ml and 10μg/ml, and that false positive results can be obtained at concentrations greater than 100μg/ml. Therefore, the positive results obtained with some of the UV filter chemicals only at concentrations greater than 100μg/ml do not indicate a phototoxic potential in vivo. When this information was taken into account during calculation of the overall predictivity of the 3T3 NRU PT test in the present study, an almost perfect correlation of in vitro versus in vivo results was obtained (between 95% and 100%), when either PIF or MPE were used to predict the phototoxic potential. The management team and participants therefore conclude that the 3T3 NRU PT test is a valid test for correctly assessing the phototoxic potential of UV filter chemicals, if the defined concentration limits are taken into account.

Quantum Dots CdSe/ZnS-Loaded Poly(D,L-Lactide-Co-Glycolide) Nanoparticles: Physicochemical Characterization and Application

2006 ◽  
Vol 505-507 ◽  
pp. 667-672 ◽  
Author(s):  
Chih Hui Yang ◽  
Kuo Chin Lin ◽  
Yu Huai Chang ◽  
Yu Cheng Lin
Keyword(s):  
Quantum Dots ◽  
Fluorescence Intensity ◽  
Fluorescence Spectra ◽  
Uv Light ◽  
Physicochemical Characterization ◽  
Plga Nanoparticles ◽  
Optimum Concentration ◽  
Cellular Internalization ◽  
Optimum Concentration Range

This paper described and characterized the quantum dots (QDs) with/without the polymeric PLGA applied in MC3T3E-1 delivery. Neat QDs were treated with various solvents, temperatures, exposure time and concentration to evaluate their stability and efficacy. We found that the intensity degree of fluorescence spectra (QDs) in different solvents follows the order: ether > THF > acetone > chloroform > methanol. Importantly, the QDs become inactive after 8-hr dissolution in the solvents of ether, THF or chloroform. According to this result, acetone and methanol are ideal solvents for QDs. The optimum concentration range of QDs in acetone is 5 to 10 mg/mL. We found that no obvious difference of fluorescence intensity was detected in QDs stored respectively at 4 °C, 24 °C and 44 °C (8-hour). When QDs were exposed to UV light (312 nm) for 2 hr, serious decay of fluorescence intensity was observed. In order to extend the application of QDs in medical areas, we encapsulated them in individual biocompatible poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles for in-vitro imaging of endocytosis in MC3T3E-1 cells. We demonstrated that the polymeric PLGA have the ability to permeate the cells for cellular internalization; the endocytotic activity could be enhanced by the polymeric QDs-encapsulated PLGA.

Alkylresorcinol Homologs in Pisum sativum L. Varieties

1999 ◽  
Vol 54 (1-2) ◽  
pp. 44-48 ◽  
Author(s):  
Robert Zarnowski ◽  
Arkadiusz Kozubek
Keyword(s):  
Pisum Sativum ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Chain Length ◽  
Homologous Series ◽  
Chromatographic Mobility ◽  
Fast Blue ◽  
Pisum Sativum L ◽  
Acetone Extracts ◽  
Layer Chromatography

Acetone extracts from the seeds of Pisum sativum L. sensu lato (Leguminoseae) separated by thin layer chromatography revealed the occurrence of hands with chromatographic mobility and color reaction with Fast Blue B characteristic for 1,3-dihydroxy-5-alkyIbenzenes. These polyketide metabolites have been isolated and identified by Spectroscopic means. The occurrence of homologous series of saturated (approximately 70%) and enoic (mono and diunsaturated) homologs with chain length of C15 to C25 has been revealed with C17 as the main homolog

Identification of Mammalian Feces by Coprostanol Thin Layer Chromatography: Method Development

1987 ◽  
Vol 70 (3) ◽  
pp. 496-498
Author(s):  
George P Hoskin ◽  
Ruth Bandler
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Method Development ◽  
Phosphomolybdic Acid ◽  
Fecal Indicator ◽  
Chromatography Method ◽  
Heat Stable ◽  
Visual Identification ◽  
Chromatography Plate ◽  
Layer Chromatography

Abstract Existing methods for the identification of mammalian fecal particles in foods have not heen completely satisfactory because visual identification of small particles is difficult. In addition, identification of feces by determining the presence of fecal alkaline phosphatase is limited to specimens in which the enzyme has not been inactivated, and it does not work well with feces from herbivores. A new method has been developed which uses coprostanol as a fecal indicator. Coprostanol is a heat-stable sterol found in the feces of mammals and some birds. A hexane extract of the suspect particle is applied to the preadsorbent zone of a silica gel thin layer chromatography plate which has been impregnated with 5% phosphomolybdic acid in ethanol. The plate is developed in diethyl ether-heptane (55 + 45), heated, and examined visually for the presence of coprostanol. Amounts of rat feces as small as 0.15 mg and cow feces as small as 0.5 mg have been identified using this method.

A light and electron microscope study of the interaction of soil bacteria with Phytophthora cinnamomi Rands

1977 ◽  
Vol 23 (11) ◽  
pp. 1518-1525 ◽  
Author(s):  
N. Malajczuk ◽  
H. J. Nesbitt ◽  
A. R. Glenn
Keyword(s):  
Soil Bacteria ◽  
Phytophthora Cinnamomi ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Microbial Association ◽  
Reproductive Structures ◽  
Streptomyces Spp ◽  
Lysis Inhibition ◽  
Zoospore Production

Light- and electron-microscopic examination showed that bacteria became associated with the hyphae and asexual reproductive structures of P. cinnamomi in soil. In suppressive soils this association appears to be correlated with hyphal lysis, inhibition of zoospore production, and sporangial breakdown. One notable feature of the microbial association between P. cinnamomi and soil bacteria is the formation of extensive slime material. Many of the bacteria isolated from the fungal hyphosphere display antagonism to the growth of P. cinnamomi in vitro. The bacteria are morphologically varied and include Pseudomonas, Bacillus, and Streptomyces spp. These observations suggest that the appropriate manipulation of the antagonistic bacteria may provide a means of biological control of P. cinnamomi.

scholarly journals Activity Test, Selectivity, Stability of Chitinase on Amobil Chitosan Membranes

2021 ◽  
Vol 8 (7) ◽  
pp. 453
Author(s):  
Hamsina Hamsina ◽  
M Tang ◽  
Erni Indrawati Ruslan Hasani
Keyword(s):  
Enzyme Immobilization ◽  
Research Method ◽  
Thermophilic Bacteria ◽  
Chitinase Activity ◽  
Optimum Concentration ◽  
Optimum Temperature ◽  
Optimum Time ◽  
Heat Stable ◽  
Activity Test ◽  
Chitosan Membranes

The use of enzymes for industrial functions needs enzymes that are stable, selective and might be used repeatedly. The aim of the study was to determine the chitinase enzyme's function, selectivity, and stability in amobil chitosan membranes. The research method consisted of stages: production of the chitinase enzyme which included the manufacture of chitin colloidal substrate, rejuvenation of thermophilic bacteria, preparation of the inoculum and determining the optimum time of production, fractionation of ammonium sulfate, chitinase enzyme immobilization technique and activity, stability and selectivity test of amobil enzyme. The results demonstrated that chitinase activity, which incorporates the optimum temperature and thus the optimum concentration of production within the immobilization technique, had an optimum temperature of 65oC on day 4 of production time with an OD value of 0.9876. The selectivity of amobil chitinase with metal ions Cd (II), Pb (II), Zn (II), and Hg (II) demonstrated that amobil chitinase was selective for these ions. Eamobil chitinase was heat stable at 55-75oC and resistant to organic solvents, suggesting that it could be used repeatedly.

Separation and Purification of Alcaligenes Biodemulsifier by Dichloromethane-Water Extraction and Silica Gel Column Chromatograph

2011 ◽  
Vol 108 ◽  
pp. 152-158
Author(s):  
Xiang Feng Huang ◽  
Kai Ming Peng ◽  
Li Jun Lu ◽  
Jia Liu
Keyword(s):  
Amino Acid ◽  
Infrared Spectrum ◽  
Thin Layer ◽  
Silica Gel ◽  
Crude Extract ◽  
Active Substance ◽  
Oil Industry ◽  
Water Extraction ◽  
Separation And Purification ◽  
Layer Chromatography

Biodemulsifier is one of the green demulsifier which could be hopeful used in crude oil industry. In this paper, pretreatment with dichloromethane and water extraction was used to extract active demulsification substance from the demulsifying bacteria Alcaligenes sp. S-XJ-1. The crude extract were consist of four amino compounds and one composition of saccharide by thin layer chromatography. It was established experiment condition of silica gel column chromatograph for crude extract purification. Demulsification ratio of the purified sample G4 was 70.8% after 48h. The purified active substance was a peptide compound by further analysed with infrared spectrum and amino acid analysis.

AN ANTIBIOTIC PRODUCED BY MICROCOCCUS EPIDERMIDIS

1950 ◽  
Vol 28e (5) ◽  
pp. 212-216 ◽  
Author(s):  
L. J. Loeb ◽  
A. Moyer ◽  
R. G. E. Murray
Keyword(s):  
Molecular Weight ◽  
Streptococcus Pyogenes ◽  
Water Purification ◽  
Active Substance ◽  
Test Organism ◽  
Chemical Data ◽  
Low Molecular Weight ◽  
Heat Stable ◽  
Wide Range ◽  
Physical And Chemical

A stable antibiotic was produced by a strain of Micrococcus epidermidis that showed a wide range of activity against Gram-positive organisms. A mucoid Streptococcus pyogenes was used as test organism. This strain could be made resistant by being grown in increasing concentrations of antibiotic but the organism reverted to its original susceptibility immediately on transfer to medium without antibiotic. There was no antiluminescent activity when tested on Photobacterium fischeri. The test organism was not lysed by the antibiotic. The active substance was dialyzable, was remarkably heat stable, and was soluble only in water or, providing water was present, in solvents that were completely miscible with water. Purification was successful only to the extent of removing a number of inactive fractions by differential solubilities. The activity was destroyed by trypsin but not by pepsin. The physical and chemical data make it probable that the substance is a polypeptide of low molecular weight.

scholarly journals Physicochemical properties of selected herbicidal products containing nicosulfuron as an active ingredient

2020 ◽  
Vol 18 (1) ◽  
pp. 438-442
Author(s):  
Katarzyna Szwedziak ◽  
Żaneta Grzywacz ◽  
Ewa Polańczyk ◽  
Sławomir Tomaszewski ◽  
Wiktoria Wojtkiewicz
Keyword(s):  
Water Quality ◽  
Biological Activity ◽  
Physicochemical Properties ◽  
Active Substance ◽  
Chromatographic Method ◽  
Plant Protection ◽  
Mineral Salts ◽  
Concentrated Suspension ◽  
Agricultural Equipment ◽  
Negative Effect

AbstractNicosulfuron is a herbicide used for plant protection. This paper presents the results of research on the physicochemical properties of three herbicidal preparations containing nicosulfuron as the active substance by measuring and comparing its concentration by the chromatographic method. These preparations are in the form of a concentrated suspension intended for dilution with water, and due to the fact that nicosulfuron contained in the tested preparations is sensitive to water quality, while checking the physicochemical properties of the preparations, a dispersion for soft (pH: 5–7) and hard (pH: 8–9) water was also determined. It is important to note that high content of mineral salts in water may have a negative effect on the biological activity of the substance. In addition, the use of herbicides does not only apply to the use of appropriate dilutions, which are effective and not harmful to the environment. However, it is also important to consider specific farmer and equipment used, so that the preparation is easy to use and does not adversely affect the kit used for spraying. This study has shown that depending on the preparation used based on the amount of active substance 40 g/l, the amount of nicosulfuron varies. The test indicators in the form of pH and density are similar, while during the tested dispersion, differences depending on the tested water were observed (sediments were observed in only one preparation tested). Differences depending on the occurrence of sediments in the water used, both at 0 and 24 h, are signaling in favor of the soft water. Therefore, it is important to assess the hardness of the water, which in turn guarantees a reduction of the amount of deposits and protection of agricultural equipment used for spraying.

scholarly journals OPTIMASI KONSENTRASI SUBSTRAT XILAN AMPAS TAHU TERHADAP ENDO-Β-1,4-D-XYLANASE UNTUK MEMPRODUKSI XILOOLIGOSAKARIDA

2016 ◽  
Vol 1 (2) ◽  
pp. 73
Author(s):  
Anak Agung Istri Ratnadewi ◽  
Wuryanti Handayani ◽  
Siti Nur Avida
Keyword(s):  
Thin Layer ◽  
Substrate Concentration ◽  
Reducing Sugars ◽  
Optimum Concentration ◽  
Bacillus Sp ◽  
Soy Milk ◽  
Hydrolysis Products ◽  
Total Reducing Sugars ◽  
Removal Of Fat ◽  
Layer Chromatography

AbstrakAmpas tahu merupakan limbah samping dari proses pengolahan tahu dan susu kedelai. Ampas tahu berpotensi sebagai sumber xilan. Xilan digunakan sebagai substrat endo-β-1,4-D-xilanase untuk menghasilkan xilooligosakarida. Penelitian ini digunakan xilan ampas yang telah dihilangkan lemak dan protein tanpa penghilangan lignin (X1nD). Xilan ampas tahu tanpa penghilangan lemak dan protein tetapi dilakukan penghilangan lignin (X2D). Enzim yang digunakan adalah endo-β-1,4-D-xilanase dari isolat Bacillus sp. asal abdomen rayap. Optimasi variasi konsentrasi substrat bertujuan untuk mengetahui konsentrasi optimum dalam menghasilkan xilooligosakarida. Produk hidrolisis yang dihasilkan dianalisis menggunakan metode Miller untuk mengetahui total gula pereduksi. Produk hidrolisis konsentrasi optimum dianalisis menggunakan Kromatografi Lapis Tipis (KLT) untuk mengetahui komponen penyusun xilooligosakarida. Substrat X1nD dan X2D optimum pada konsentrasi 6% dan 5% dengan total gula pereduksi sebesar 0,196 mg/ml dan 0,211 mg/ml. Komponen penyusun xilooligosakarida ampas tahu berupa xilotriosa (X3), xilotetraosa (X4), dan xilopentaosa (X5).Kata Kunci: Ampas tahu, endo-β-1,4-D-xilanase, xilan, xilooligosakarida. AbstractOkara is a waste byproduct of the processing of tofu and soy milk. Okara potential as a source of xylan. Xylan is used as the substrate endo-1,4-β-D-xylanase to produce xyloologosaccharide. This study used okara xylan had eliminated fat and protein without removal of lignin (X1nD). Okara xylan out without the removal of fat and protein but do removal of lignin (X2D). The enzyme used is endo-1,4-β-D-xylanase of isolates of Bacillus sp. From abdominal termites. Optimization of substrate concentration variation aims to determine the optimum concentration in generating xyloologosaccharide. Hydrolysis products were analyzed using Miller method to determine total reducing sugars. The optimum concentration of hydrolysis products were analyzed using Thin Layer Chromatography (TLC) to determine the components of xyloologosaccharide. X1nD and X2D optimum substrate at a concentration of 6% and 5% to the total reducing sugars of 0.196 mg/ml and 0.211 mg/ml. Xyloologosaccharide of okara components of the pulp out the form xylotriose (X3), xylotetraose (X4), and xylopentaose (X5).Keywords: Okara, endo-1,4-β-D-xylanase, xylan, xyloologosaccharide

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