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Combination of cobalt bis(dicarbollide) amino derivative and antibiotic effect on growth of staphylococcus epidermidis
Lokočová, K. ; Vaňková, E. ; Šícha, Václav ; Masák, J.
Nosocomial infections are often caused by bacteria from the Staphylococcus genus. The clinically relevant representatives of this species are Staphylococcus epidermidis and Staphylococcus aureus which grow predominantly as surface-attached stable communities known as biofilms. Cells in these biofilms are often highly resistant to antibiotics. Therefore, new antimicrobial or antibiofilm substances are still being developed. In this study, we investigated the influence of cobalt bis(dicarbollide) or its amino derivatives, and antibiotics (erythromycin, tetracycline)-alone and in combination-to determine the antimicrobial activity and the inhibition of biofilm formation against three type strains of S. epidermidis. We used a microcultivation device to determine the minimum inhibitory concentrations and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay to determine the metabolic activity of the cells in biofilms. We observed the synergistic effect of cobalt bis(dicarbollide) and its amino derivatives with both the antibiotics on both the planktonic and biofilm cells.
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Preparation of Chitosan Based Films for Food Packaging Applications.
Soukup, Karel ; Cruz, G.J.F. ; Hanika, Jiří ; Jandová, Věra ; Hejtmánek, Vladimír ; Šolcová, Olga
In the present study, the effect both of the botanical source and proportion of starch produced from agricultural surplus on the microstructure properties of starch/chitosan/glycerin films was tested. Effective gas transport properties gas diffusion transfer was performed. Starch/chitosan/glycerol biodegradable films were obtained by casting method from giant squid (Dosidicus gigas) pen chitosan mixed with glycerin and starch. Four starch samples were prepared using exceeding or low quality biomass including broken rice grains, hard yellow corn surplus, banana surplus form exportation activity and low quality cassava in three different weight proportion (chitosan/starch) corresponding to 1/1, 2/1 and 5/1. Extraction of starch from the raw material was carried out by mixing it with a water solution of sodium disulfite (5 wt.%). Afterwards, the obtained suspension was filtered and then decanted at 5°C for 24 h. The obtained starch was washed repeatedly with distilled water and ethanol (96 vol.%). Finally, the starch samples were dried at 55°C for 48 h, crushed and sieved. It was found that the gas diffusion transport properties significantly depend on the starch source used. Differences in diffusion transport rates through the films prepared with different starches are related to the size and distribution of granules of starch in the films and/or the amylose conten.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22019011614490 - PDF
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Recovery of Waste Semiconductors for CVD Precursors.
Bumba, Jakub ; Dytrych, Pavel ; Fajgar, Radek ; Dřínek, Vladislav
The newly patented method for regeneration of ultrapure silicon and germanium via magnesium silicide and magnesium germanide from waste photovoltaic (PV) cells, broken germanium lenses and waste magnesium chips was utilized to obtain chemical vapour deposition (CVD) precursors for application in electronics, optics or nanoparticles synthesis. Magnesium silicide and germanide were prepared directly by thermal synthesis from waste materials in optimized tube reactor at 400°C and 5 Pa. X-Ray Diffraction (XRD) confirmed 97.9% respective 95% purity of products. The presence of silicon and germanium hydrides (CVD precursors) prepared by acid hydrolysis in the second step of the process was verified by Gas Chromatography–Mass Spectroscopy (GC/MS) and Fourier Transform Infrared Spectroscopy (FTIR). The crude, unrefined mixture of silicon hydrides served as raw material for CVD experiment at different substrates. SEM images confirmed occurrence of various micro and nano particles which could be used in electronics, optics and catalysis.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22019011614381 - PDF
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Simultaneous Hydrolysis of Proteins and Fats fro Waste Chicken Feathers.
Rousková, Milena ; Šolcová, Olga ; Šabata, Stanislav ; Jírů, M. ; Hůrková, K. ; Hanika, Jiří
The kinetics of the simultaneous hydrolysis of macromolecular proteins (keratin) and lipids (fat) from waste chicken feathers was investigated in this study. The perspective option pressure hydrolysis at elevated temperature was designed as one of the primary tasks within the research program in frame of the Competence Centre BIORAF, supported by the Technology Agency of the CR. The process development of simultaneous hydrolysis of proteins and lipids contained in the waste is focused on this potential alternative raw material for the preparation of valuable amino acids1 and proteins of low molecular weight. In this study, the acidic hydrolysis kinetics of the waste biomass was performed using a batch stirred bench scale autoclave at elevated temperature and pressure of inert atmosphere from 0.9 to 2.3 MPa. Produced hydrolysate was filtrated and subsequently analyzed using HPLC/MS method at the UCT Prague.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22019011614371 - PDF
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Volatile Substances Determination in Magnolia x Pruhoniciana Extracts.
Rousková, Milena ; Šabata, Stanislav ; Maléterová, Ywetta ; Hradecký, J. ; Hanika, Jiří ; Kaštánek, František ; Šolcová, Olga
Magnolia pruhoniciana is a unique hybrid originated by the crossing of Japanese M. obovata and American M. tripetala. It has been cultivated and grown since the 1950s in the Průhonice park, part of the Institute of Botany of the CAS. However, biologically active substances contained in intensely fragrant blossoms have not been\nsufficiently described, yet. From that reason the research was focused on extraction of the volatile substances from fresh blossoms using various solvents. Samples of magnolia blossom extracts revealed variously rich profiles of volatile substances, depending on the extraction agent used. To obtain information on volatile substances the analytical method GC/HRMS was employed. Magnolia extracts contained a large number of valuable substances such as alkaloids, coumarins, flavonoids, lignans and neolignans, phenyl-propanoids and terpenes have been identified. Obtained extracts possessed a typical magnolia fragrance, which confirmed that the obtained products could be potentially used for cosmetic applications.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22019011614380 - PDF
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Pilot Scale Testing of Electrocoagulation to Remove Cr6 +, Ni and Zn from Contaminated Groundwater.
Mašín, P. ; Krystyník, Pavel ; Klusoň, Petr ; Krušinová, Z.
Testing has shown a high efficiency in removal of toxic metals, especially chromium (Cr6+ and Crcelk.). The content of contaminants in treated water was mostly under limits for discharging water into the surface water recipient. The pH 4.5 of inlet water was optimal for the electrochemical reduction of Cr6+ to Cr3+ followed by coagulation. Increase of pH was performed in order to increase efficiency of Ni removal. The power input of electrode cells at the current input of 45 A was 1.3 kWh.m-3 of cleaned water. The life of one electrode pack was 35 m3 of contaminated water at mentioned current input.
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