Release of cell-bound polygalacturonase and cellulase from mycelium of Rhizoctonia solani

1975 ◽  
Vol 21 (4) ◽  
pp. 521-526 ◽  
Author(s):  
N. Lisker ◽  
J. Katan ◽  
I. Chet ◽  
Y. Henis

Propagules of Rhizoctonia solani grown in modified Czapek's medium containing sodium polypectate or carboxymethyl cellulose as a sole carbon source produced both extracellular and cell-bound polygalacturonase (PG), and cellulase (Cx), respectively. The cell-bound enzymes can be released to various extents by shaking the germinating propagules in solutions of NaCl, KCl, phosphate buffer, Na2EDTA (ethylenediaminetetraacetate), detergents such as Triton X-100 (octyl phenoxypolyethoxyethanol), Tween 80 (polyoxyethylene sorbitan monooleate), Celmusol, and distilled water. Sodium dodecyl sulfate (SDS) inactivated both PG and Cx but did not affect Cx activity in phosphate buffer solution. PG was more easily released by salts from the mycelium of R. solani than Cx. The release of both enzymes was a passive process and was not due to an osmotic effect. The amount of the cell-bound fraction was correlated with the total amount of the extracellular fraction rather than with the mycelial growth. At least one-third of the cell-bound fractions of both enzymes was found to be associated with the cell wall fraction of the mycelium.

Author(s):  
B. S. Burlaka

Interleukin-1 receptor antagonist (IL-1Ra) is an active pharmaceutical ingredient obtained by the method of gene transformation of Escherichia coli, provides a neuroprotective effect, namely – inhibition of oxidative modification of proteins, normalization of functional activity of mitochondrial energy, mitochondrial energy. Early complex physical-chemical, microbiological, and biopharmaceutical studies have developed a new intranasal formulation, the formulation of which contains: IL-1Ra, sodium carboxymethyl cellulose, D-panthenol, benzalkonium chloride, trilon B, Tween-80, phosphate buffer solution. Given the peculiarities of the technological process, when creating a new gel dosage form, it is necessary to justify the temperature of the carrier base, the introduction of the active substance into the base, as well as to predict the possible chemical interaction of individual components in the dosage form. Therefore, the application of thermogravimetric analysis in pharmaceutical technology is relevant. The aim of the work is to conduct thermogravimetric studies of a new nasal form with an antagonist of interleukin-1β (IL-1Ra). Materials and methods. The objects of thermogravimetric studies were: semi-finished product-solution of the receptor antagonist of interleukin-1 (IL-1Ra). Excipients were: sodium carboxymethylcellulose, tween-80, D-panthenol, trilon B, benzalkonium chloride. To ensure the appropriate pH value used phosphate buffer solution (pH 6.0), according to the recipe to State Pharmacopoeia 2 ed. In addition to the individual components of the finished nasal gel, also prepared nasal gel without IL-1Ra, as well as gel with IL-1Ra. The thermographic analysis was performed on a derivatograph – Shimadzu DTG-60 (Japan) with a platinum-platinum-rhodium thermocouple when heating the samples in aluminum crucibles (from 15 °C to 250 °C). Al2O3 was used as a reference substance. The heating rate was 10 °C per minute. The weight of the test samples ranged from 19.22 mg to 52.91 mg. The derivatograph graphically recorded the obtained data in the form of curves T, DTA, TGA. The T curve on the derivatogram shows the change in temperature, and the TGA curve shows the change in mass of the sample during the study period. The DTA curve reflects the differentiation of thermal effects, contains information about endothermic and exothermic maxima, can be used for qualitative evaluation of the derivatogram. Results. The study consisted of two stages. At the first stage, we studied the derivatograms of experimental samples – individual ingredients of the finished nasal gel - active and excipients, namely: IL-1Ra, sodium carboxymethylcellulose, tween-80, D-panthenol, trilon B, benzalkonium chloride, phosphate buffer solution 6.0. In the second stage, samples of nasal gels were prepared: nasal gel with the required amount of excipients, in addition to the active substance – IL-1Ra, as well as a nasal gel containing IL-1Ra and the required amount of excipients. As a result, we obtained some parameters of thermogravimetric analysis in the form of a graphical image – derivatograms, which were then analyzed. Conclusions. Thermogravimetric studies of individual components of nasal gel with IL-1Ra, as well as nasal gels with active substance and without active substance, were found that the manufacturing process of gel with IL-1Ra should be carried out taking into account thermolabile compounds. First, you need to prepare the base without preservative and IL-1Ra. Then at a temperature not exceeding 40 °C dissolve the preservative, and then when cooled to 20 °C add IL-1Ra. It was found that the developed dosage form of the gel with IL-1Ra is a mixture of active and excipients, the ingredients of which do not interact with each other and can be combined in one dosage form.


2011 ◽  
Vol 284-286 ◽  
pp. 1764-1769 ◽  
Author(s):  
Vitalijs Lakevics ◽  
Janis Locs ◽  
Dagnija Loca ◽  
Valentina Stepanova ◽  
Liga Berzina-Cimdina ◽  
...  

Sorption experiments of bovine serum albumin (BSA) on hydroxyapatite (HAp) ceramic granules, prepared at three temperatures 900°C, 1000°C and 1150°C were performed at room temperature 18,6 °C and phosphate buffer, pH 5,83; 6.38 and 7,39. Thermal treatment contributed to the decrease of bovine serum albumin immobilization indicating that sorption process depended on HAp ceramics specific surface area and pH values of phosphate buffer solution. However, it was confirmed that granule size was also an important parameter for bovine serum albumin adsorption. As a result of these experiments, the most appropriate adsorption conditions and phosphate buffer pH values influence on to BSA sorption were analyzed.


2000 ◽  
Vol 63 (6) ◽  
pp. 703-708 ◽  
Author(s):  
MARCY A. WISNIEWSKY ◽  
BONITA A. GLATZ ◽  
MARK L. GLEASON ◽  
CHERYLL A. REITMEIER

The objectives of this study were to determine if washing of whole apples with solutions of three different sanitizers (peroxyacetic acid, chlorine dioxide, or a chlorine-phosphate buffer solution) could reduce a contaminating nonpathogenic Escherichia coli O157:H7 population by 5 logs and at what sanitizer concentration and wash time such a reduction could be achieved. Sanitizers were tested at 1, 2, 4, 8, and 16 times the manufacturer's recommended concentration at wash times of 5, 10, and 15 min. Whole, sound Braeburn apples were inoculated with approximately 1 × 108 or 7 × 106 CFU per apple, stored for 24 h, then washed with sterile water (control) or with sanitizers for the prescribed time. Recovered bacteria were enumerated on trypticase soy agar. Washing with water alone reduced the recoverable population by almost 2 logs from the starting population; this can be attributed to physical removal of organisms from the apple surface. No sanitizer, when used at the recommended concentration, reduced the recovered E. coli population by 5 logs under the test conditions. The most effective sanitizer, peroxyacetic acid, achieved a 5-log reduction when used at 2.1 to 14 times its recommended concentration, depending on the length of the wash time. The chlorine-phosphate buffer solution reduced the population by 5 logs when used at 3 to 15 times its recommended concentration, depending on wash time. At no concentration or wash time tested did chlorine dioxide achieve the 5-log reduction.


2018 ◽  
Vol 10 (11) ◽  
pp. 1362-1371 ◽  
Author(s):  
Mallappa Mahanthappa ◽  
Nagaraju Kottam ◽  
Shivaraj Yellappa

The simultaneous electroanalysis of acetaminophen (AC), guanine (G) and adenine (A) was successfully achieved on the zinc sulphide nanoparticles-modified carbon paste electrode (ZnS NPs/CPE) in phosphate buffer solution (PBS).


Author(s):  
Amitava Dutta ◽  
Apurba Kumar Santra ◽  
Ranjan Ganguly

Abstract We present a detailed numerical analysis of electrophoresis induced concentration of a bio-analyte facilitated by temperature gradient focusing in a phosphate buffer solution via Joule heating inside a converging-diverging microchannel. The purpose is to study the effects of frequency of AC field and channel width variation on the concentration of target analyte. We tune the buffer viscosity, conductivity and electrophoretic mobility of the analyte such that the electrophoretic velocity of the analyte locally balances the electroosmotic flow of the buffer, resulting in a local build-up of the analyte concentration in a target region. An AC field is superimposed on the applied DC field within the microchannel in such a way that the back pressure effect is minimized, resulting in minimum dispersion and high concentration of the target analyte. Axial transport of fluorescein-Na in the phosphate buffer solution is controlled by inducing temperature gradient through Joule heating. The technique leverages the fact that the buffer's ionic strength and viscosity depends on temperature, which in turn guides the analyte transport. A numerical model is proposed and a finite element-based solution of the coupled electric field, mass, momentum, energy and species equations are carried out. Simulation predict peak of 670-fold concentration of fluorescein-Na is achieved. The peak concentration is found to increase sharply as the channel throat width, while the axial spread of concentrated analyte increases at lower frequency of AC field. The results of the work may improve the design of micro concentrator.


Author(s):  
Diego Ramirez ◽  
Liz J. Shaw ◽  
Chris D. Collins

Abstract Different physicochemical and biological treatments have been used to treat oil sludges, and oil recovery techniques are preferred such as oil sludge washing (OSW) with surfactants and co-solvents. Toluene is commonly used as co-solvent, but it is non-benign to the environment. This study tested alternative co-solvents (n-pentane, n-hexane, cyclohexane, and isooctane) at 1:1 and 2:1 C/OS (co-solvent to oil sludge ratio). Also, this study evaluated the effect on the oil recovery rate (ORR) of three main parameters in the washing: type, concentration, and application ratio (S/OS) of surfactants to oil sludges. To date, no study has assessed these parameters in the washing of oil sludges from different sources. Four types of oil sludges and five surfactants (Triton X-100 and X-114, Tween 80, sodium dodecyl sulphate (SDS), and rhamnolipid) were used. The results showed that cyclohexane had high ORR and could be used instead of toluene because it is more benign to the environment. The S/OS ratio had a high effect on the ORR and depended on the type of oil sludge. Rhamnolipid, Triton X-100, and Triton X-114 had the highest oil recovery rates (40 – 70%). In addition, it was found that the surfactant concentration had no effect on the ORR. Consequently, the addition of surfactant was not significantly different compared to the washing with no surfactants, except for one sludge. The use of the surfactant in the washing solution can help in the selective extraction of specific oil hydrocarbon fractions in the recovered oil to assess its potential reuse as fuel. Further recommendations were given to improve the OSW process.


2018 ◽  
Vol 5 (1) ◽  
pp. 1 ◽  
Author(s):  
Jessica Oliveira ◽  
Raquel Rodrigues ◽  
Lillian Barros ◽  
Isabel Ferreira ◽  
Luís Marchesi ◽  
...  

In this study, hydrophilic magnetic nanoparticles were synthesized by green routes using a methanolic extract of Rubus ulmifolius Schott flowers. The prepared magnetic nanoparticles were coated with carbon-based shell for drug delivery application. The nanocomposites were further chemically functionalized with nitric acid and, sequentially, with Pluronic® F68 (CMNPs-plur) to enhance their colloidal stability. The resulting material was dispersed in phosphate buffer solution at pH 7.4 to study the Doxorubicin loading. After shaking for 48 h, 99.13% of the drug was loaded by the nanocomposites. Subsequently, the drug release was studied in different working phosphate buffer solutions (i.e., PB pH 4.5, pH 6.0 and pH 7.4) to determine the efficiency of the synthesized material for drug delivery as pH-dependent drug nanocarrier. The results have shown a drug release quantity 18% higher in mimicking tumor environment than in the physiological one. Therefore, this study demonstrates the ability of CMNPs-plur to release a drug with pH dependence, which could be used in the future for the treatment of cancer "in situ" by means of controlled drug release.


1950 ◽  
Vol 91 (6) ◽  
pp. 655-664 ◽  
Author(s):  
Armin F. Schick ◽  
George M. Hass

A new method for the isolation of large numbers of individual myofibrils from fresh mammalian skeletal and cardiac muscle has been described. Purification of isolated myofibrils was accomplished by differential centrifugation of fresh frozen sections of muscle which had been mechanically agitated after exposure for 30 to 45 minutes at 0°C. to the action of a dilute solution of trypsin in a phosphate buffer solution with a pH of 7.0 and an ionic strength of 0.25. Isolated skeletal myofibrils of the rabbit and man have similar constant solubility properties. They dissolve in an aqueous mixture of 0.5 N potassium chloride and 0.03 N sodium bicarbonate, giving viscous solutions which exhibit conspicuous birefringence of flow. They are soluble in buffer solutions (ionic strength 0.15) on the acid side of pH 4 and alkaline side of pH 10. If the ionic strength of potassium phosphate buffer solutions is increased to 0.5 or if the ionic strength of phosphate-borate buffer solutions is increased to a similar value by addition of potassium chloride, the isolated myofibrils become soluble at neutrality. Hence, it is possible, first to isolate the myofibrils and then dissolve them without deviating appreciably from physiologic ranges of pH. The extent to which myofibrils are modified by the conditions imposed by the method of isolation is unknown. There is no significant change in microscopic structure or optical birefringence. Furthermore, there is retention of a form of physiological reactivity, for when the isolated skeletal myofibrils are immersed in solutions of adenosinetriphosphate, they promptly and irreversibly change from elongated fibrils with distinct structural detail into dense spherical masses without recognizable microscopic structure.


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