M. Urík, J. Ševc, P. Littera, M. Kolenčík, S. Čerňanský
Filamentous fungus Aspergillus niger is commonly found on decaying vegetation or in indoor environment and has a number of uses, including application in bioremediation. Hence, the basic interactions of this common mould with selenite were studied, including biovolatilization, bioaccumulation and toxicity effects of selenite on fungal growth. The fungal strain, originally isolated from noncontaminated soil, was cultivated under aerobic conditions on liquid cultivation media with concentration of Se(IV) 19 or 27 mg.l-1 during 25 days. The fungal growth in the presence of selenite was not inhibited when compared to control, only the sporulation was reduced. The concentration of Se(IV) in liquid medium decreased rapidly within first ten days to 1 mg.l-1. However, according to results from the 25th day of cultivation, the concentration of total selenium in medium did not change significantly and only negligible amount of selenium (less then 1%) was bioaccumulated. That indicates some biotransformation of selenite into other selenium species. During the cultivation, up to 21% of total amount of selenium was transformed into volatile derivatives (biovolatilization) by filamentous fungus A. niger.
{"title":"Basic interactions of Aspergillus niger with Se(IV)","authors":"M. Urík, J. Ševc, P. Littera, M. Kolenčík, S. Čerňanský","doi":"10.36547/nbc.1219","DOIUrl":"https://doi.org/10.36547/nbc.1219","url":null,"abstract":"Filamentous fungus Aspergillus niger is commonly found on decaying vegetation or in indoor environment and has a number of uses, including application in bioremediation. Hence, the basic interactions of this common mould with selenite were studied, including biovolatilization, bioaccumulation and toxicity effects of selenite on fungal growth. The fungal strain, originally isolated from noncontaminated soil, was cultivated under aerobic conditions on liquid cultivation media with concentration of Se(IV) 19 or 27 mg.l-1 during 25 days. The fungal growth in the presence of selenite was not inhibited when compared to control, only the sporulation was reduced. The concentration of Se(IV) in liquid medium decreased rapidly within first ten days to 1 mg.l-1. However, according to results from the 25th day of cultivation, the concentration of total selenium in medium did not change significantly and only negligible amount of selenium (less then 1%) was bioaccumulated. That indicates some biotransformation of selenite into other selenium species. During the cultivation, up to 21% of total amount of selenium was transformed into volatile derivatives (biovolatilization) by filamentous fungus A. niger.","PeriodicalId":19210,"journal":{"name":"Nova Biotechnologica et Chimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41997990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aim of this study was optimization of rosmarinic acid extraction from lemon balm (Melissa officinalis). The optimal conditions for the extraction of rosmarinic acid from lemon balm were determined using response surface methodology (RSM). A center composide design (CCD) was used to investigate the effects of three independent variables, namely solid-liquid radio, solvent composition (%) and extraction temperature (°C). Dependent variable was yield of rosmarinic acid. A second-order polynomial model was used for predicting the response. Optimized conditions for rosmarinic acid were: PEME 1:29 (w/v), temperature 66 °C a % propan-2-ol 34 %. The experimental values agreed with predicted within a 95 % confidence interval. Yield of rosmarinic acid extraction by these optimized conditions was achieved 72.6 mg of rosmarinic acid / g of dry extraction matter.
{"title":"Optimization of rosmarinic acid extraction from lemon balm (Melissa officinalis)","authors":"M. Ondrejovič, H. Benkovičová, S. Šilhár","doi":"10.36547/nbc.1275","DOIUrl":"https://doi.org/10.36547/nbc.1275","url":null,"abstract":"The aim of this study was optimization of rosmarinic acid extraction from lemon balm (Melissa officinalis). The optimal conditions for the extraction of rosmarinic acid from lemon balm were determined using response surface methodology (RSM). A center composide design (CCD) was used to investigate the effects of three independent variables, namely solid-liquid radio, solvent composition (%) and extraction temperature (°C). Dependent variable was yield of rosmarinic acid. A second-order polynomial model was used for predicting the response. Optimized conditions for rosmarinic acid were: PEME 1:29 (w/v), temperature 66 °C a % propan-2-ol 34 %. The experimental values agreed with predicted within a 95 % confidence interval. Yield of rosmarinic acid extraction by these optimized conditions was achieved 72.6 mg of rosmarinic acid / g of dry extraction matter.","PeriodicalId":19210,"journal":{"name":"Nova Biotechnologica et Chimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43814326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chemometrics is a scientific discipline closely connected with statistics and mathematics. It has an important role in analytical chemistry. Modern analytical methods provide opportunity to collect large amounts of data for various samples. For handling analytical results different chemometric methods are employed, such as basic statistical methods for the determination of mean and median values, standard deviations, minimal and maximal values of measured parameters and their mutual correlation coefficients, the principal component analysis (PCA), cluster analysis (CA), and linear discriminant analysis (LDA). The objectives of chemometrics in analytical chemistry are focused on characterization and chemometrical classification of different samples. The quality of environmental samples such as water, sediment, soil, air samples etc. can be determined according to measured physical and chemical parameters, which represent the individual samples. Chemometric methods give information regarding measured parameters about similarity between sampling locations, sources of pollution, seasonal behavior and time trends. Monitoring of general pollution of environmental samples and following measuring parameters which are above permitted level given by legislation can be used for searching of pollution source and for planning prevention measures from pollution. Food samples can also be characterized by chemometrical methods. Chemometrics can be used for fast and efficient determination of food sample categories, such as edible oils, wines, fruits and fruit juices etc. Classification can also be performed according to the origin, source or season. From all these facts it is evident that the aim of chemometrics in analytical chemistry is high and extensive.
{"title":"Chemometrics in analytical chemistry","authors":"Darinka Brodnjak Vončina","doi":"10.36547/nbc.1280","DOIUrl":"https://doi.org/10.36547/nbc.1280","url":null,"abstract":"Chemometrics is a scientific discipline closely connected with statistics and mathematics. It has an important role in analytical chemistry. Modern analytical methods provide opportunity to collect large amounts of data for various samples. For handling analytical results different chemometric methods are employed, such as basic statistical methods for the determination of mean and median values, standard deviations, minimal and maximal values of measured parameters and their mutual correlation coefficients, the principal component analysis (PCA), cluster analysis (CA), and linear discriminant analysis (LDA). The objectives of chemometrics in analytical chemistry are focused on characterization and chemometrical classification of different samples. The quality of environmental samples such as water, sediment, soil, air samples etc. can be determined according to measured physical and chemical parameters, which represent the individual samples. Chemometric methods give information regarding measured parameters about similarity between sampling locations, sources of pollution, seasonal behavior and time trends. Monitoring of general pollution of environmental samples and following measuring parameters which are above permitted level given by legislation can be used for searching of pollution source and for planning \u0000prevention measures from pollution. Food samples can also be characterized by chemometrical methods. Chemometrics can be used for fast and efficient determination of food sample categories, such as edible oils, wines, fruits and fruit juices etc. Classification can also be performed according to the origin, source or season. From all these facts it is evident that the aim of chemometrics in analytical chemistry is high and extensive.","PeriodicalId":19210,"journal":{"name":"Nova Biotechnologica et Chimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47447369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Lozzi, R. Mentag, Driss Alami-Halimi, Rabha Abdelwahd, A. Abousalim
Carob (Ceratonia siliqua L.) is an important Mediterranean plant species with worldwide commercial and medicinal uses. The establishment of a callus culture protocol as an alternative system to produce polyphenols of chemical and pharmaceutical interest was made in the present study for the first time in carob. Explant type and the light regime are two important factors that influence morphogenic responses and biochemical production. Maximal callus induction (100 %) and biomass accumulation were obtained in cotyledon explants under both tested light regimes (16-hour photoperiod and darkness). However, leaf callus produced a higher amount of polyphenols (TPC) and flavonoids (TFC) but a lower amount of total condensed tannins (TCT) as compared to cotyledon callus. Light treatment has significantly increased TCT content but decreased the antioxidant activity in carob callus cultures. Strong and positive correlations were obtained between TPC and TFC and the antioxidant activities with correlation coefficients ranging between 0.68 and 0.98. The obtained results indicate that calli of C. siliqua have the potential for enhanced production of phenolic compounds with antioxidant activity that is favored by culture under dark condition.
{"title":"Polyphenol contents and antioxidant activity of carob callus cultures","authors":"A. Lozzi, R. Mentag, Driss Alami-Halimi, Rabha Abdelwahd, A. Abousalim","doi":"10.36547/nbc.652","DOIUrl":"https://doi.org/10.36547/nbc.652","url":null,"abstract":"Carob (Ceratonia siliqua L.) is an important Mediterranean plant species with worldwide commercial and medicinal uses. The establishment of a callus culture protocol as an alternative system to produce polyphenols of chemical and pharmaceutical interest was made in the present study for the first time in carob. Explant type and the light regime are two important factors that influence morphogenic responses and biochemical production. Maximal callus induction (100 %) and biomass accumulation were obtained in cotyledon explants under both tested light regimes (16-hour photoperiod and darkness). However, leaf callus produced a higher amount of polyphenols (TPC) and flavonoids (TFC) but a lower amount of total condensed tannins (TCT) as compared to cotyledon callus. Light treatment has significantly increased TCT content but decreased the antioxidant activity in carob callus cultures. Strong and positive correlations were obtained between TPC and TFC and the antioxidant activities with correlation coefficients ranging between 0.68 and 0.98. The obtained results indicate that calli of C. siliqua have the potential for enhanced production of phenolic compounds with antioxidant activity that is favored by culture under dark condition.","PeriodicalId":19210,"journal":{"name":"Nova Biotechnologica et Chimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41268405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Formation of carnosine from histidine and b-alanine is studied by ab initio MO-LCAO-SCF method followed by the perturbative configuration interaction (MP2) in vacuo. After the full geometry optimization at the SCF level, the molecular properties were evaluated and followed by the vibrational-rotational analysis. Consequently, the energy, entropy and free energy were evaluated for the reactants and products of the reaction histidine + beta-alanine = carnosine + H2O and finally the equilibrium constant was enumerated.
{"title":"Formation of carnosine - an ab initio study","authors":"R. Boča, B. Vranovičová","doi":"10.36547/nbc.1010","DOIUrl":"https://doi.org/10.36547/nbc.1010","url":null,"abstract":"Formation of carnosine from histidine and b-alanine is studied by ab initio MO-LCAO-SCF method followed by the perturbative configuration interaction (MP2) in vacuo. After the full geometry optimization at the SCF level, the molecular properties were evaluated and followed by the vibrational-rotational analysis. Consequently, the energy, entropy and free energy were evaluated for the reactants and products of the reaction histidine + beta-alanine = carnosine + H2O and finally the equilibrium constant was enumerated.","PeriodicalId":19210,"journal":{"name":"Nova Biotechnologica et Chimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49266636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lucia Remenárová, M. Pipíška, M. Horník, J. Augustín
A biosorbent prepared from moss Rhytidiadelphus squarrosus biomass was used for biosorption of cationic dyes – Malachite green (BG4), Auramine O (BY2) and Thioflavine T (BY1) from binary aqueous solutions. Sorption data obtained at non-equilibrium conditions were analyzed by Sheindorf-Rebuhn-Sheintuch (SRS) equation (competitive model for binary systems derived from Freundlich isotherm) and extended model of Freundlich isotherm. Following the comparison of coefficient of determination values (R2) as well as values of root mean squared error (RMSE), the extended model of Freundlich isotherm was more suitable for description of investigated binary systems BG4-BY1 (R2 BG4 = 0.983, R2 BY1 = 0.993) and BG4-BY2 (R2 BG4 = 0.976, R2 BY2 = 0.995). The competition coefficients aij, obtained from SRS model can be considered as a way to quantify mutual competitive interactions. The competition coefficients indicated that the presence of BY1 in binary system decreased the sorption of BG4 (aBY1,BG4 = 0.835) while presence of BG4 (aBG4,BY1 = 0.208) has less pronounced competitive effect on the sorption of BY1 onto biosorbent. Competition coefficients obtained for binary system BY1-BG4 indicate that BG4 (aBG4,BY2 = 0.186) was more significantly affected by the presence of BY2 (aBY2,BG4 = 1.167). Finally, equations used in this work were represented by the three-imensional biosorption isotherm surfaces.
{"title":"Biosorption of cationic dyes BY1, BY2 and BG4 by moss Rhytidiadelphus squarrosus from binary solutions","authors":"Lucia Remenárová, M. Pipíška, M. Horník, J. Augustín","doi":"10.36547/nbc.1132","DOIUrl":"https://doi.org/10.36547/nbc.1132","url":null,"abstract":"A biosorbent prepared from moss Rhytidiadelphus squarrosus biomass was used for biosorption of cationic dyes – Malachite green (BG4), Auramine O (BY2) and Thioflavine T (BY1) from binary aqueous solutions. Sorption data obtained at non-equilibrium conditions were analyzed by Sheindorf-Rebuhn-Sheintuch (SRS) equation (competitive model for binary systems derived from Freundlich isotherm) and extended model of Freundlich isotherm. Following the comparison of coefficient of determination values (R2) as well as values of root mean squared error (RMSE), the extended model of Freundlich isotherm was more suitable for description of investigated binary systems BG4-BY1 (R2 BG4 = 0.983, R2 BY1 = 0.993) and BG4-BY2 (R2 BG4 = 0.976, R2 BY2 = 0.995). The competition coefficients aij, obtained from SRS model can be considered as a way to quantify mutual competitive interactions. The competition coefficients indicated that the presence of BY1 in binary system decreased the sorption of BG4 (aBY1,BG4 = 0.835) while presence of BG4 (aBG4,BY1 = 0.208) has less pronounced competitive effect on the sorption of BY1 onto biosorbent. Competition coefficients obtained for binary system BY1-BG4 indicate that BG4 (aBG4,BY2 = 0.186) was more significantly affected by the presence of BY2 (aBY2,BG4 = 1.167). Finally, equations used in this work were represented by the three-imensional biosorption isotherm surfaces.","PeriodicalId":19210,"journal":{"name":"Nova Biotechnologica et Chimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45839483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kateřina Illková, J. Omelková, Živan Gojkovic, J. Pavlačková
Fats, oils and greases in waste water frequently cause serious environmental problems. A commercial preparation was tested for its ability to degrade oil and grease in wastewater. As substrates, two fats (lard and beef fat) and four oils (rape seed oil, sunflower oil, palm oil and olive oil) were chosen. The degradation ability of commercial preparation for different substrates was investigated by the determination of lipid degradation at pH 7, temperature 25 °C, aerobic condition and agitation at 160 rev/min for 14 days in Erlenmeyer flasks. Simultaneously, the lipolytic activity was spectrophotometrically determined at 420 nm. All tested substrates were degraded by the different rate to basic units (fatty acids). Rape seed oil and lard were decomposed by bacterial lipase from commercial preparation.
{"title":"Characterization of preparation for fat separators","authors":"Kateřina Illková, J. Omelková, Živan Gojkovic, J. Pavlačková","doi":"10.36547/nbc.1130","DOIUrl":"https://doi.org/10.36547/nbc.1130","url":null,"abstract":"Fats, oils and greases in waste water frequently cause serious environmental problems. A commercial preparation was tested for its ability to degrade oil and grease in wastewater. As substrates, two fats (lard and beef fat) and four oils (rape seed oil, sunflower oil, palm oil and olive oil) were chosen. The degradation ability of commercial preparation for different substrates was investigated by the determination of lipid degradation at pH 7, temperature 25 °C, aerobic condition and agitation at 160 rev/min for 14 days in Erlenmeyer flasks. Simultaneously, the lipolytic activity was spectrophotometrically determined at 420 nm. All tested substrates were degraded by the different rate to basic units (fatty acids). Rape seed oil and lard were decomposed by bacterial lipase from commercial preparation.","PeriodicalId":19210,"journal":{"name":"Nova Biotechnologica et Chimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42274810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andrea Szabó Nagy, K. Varga, B. Baja, Z. Németh, Desző Oravetz, Zoltán Hamonnay, E. Kuzmann, J. Schunk, G. Patek
Evaluating the water chemistry in the primary circuit and the effect of chemical econtamination of the heat exchanger tubes performed by the AP-CITROX (AP: alkaline permanganate; CITROX: citric and oxalic acid) procedure at Paks NPP (Hungary), a project dealing with the comprehensive investigation of the general corrosion state of the steam generators (SGs) has been initiated. Owing to the fact that there is no investigation method available for the in-situ monitoring of the inner surfaces of heat exchanger tubes, a research program based on sampling as well as on ex-situ electrochemical (voltammetric) and surface analytical measurements (SEM-EDX, CEMS, XRD, XPS) was developed and elaborated. In the time period of 2000-2008 - within the frame of the above project - 45 stainless steel specimens, cut out from various locations of the steam generators of the Paks NPP were investigated. Based on the measured corrosion characteristics (corrosion rate, thickness and chemical composition of the protective oxide-layer) it was found that these parameters are strongly dependent on the decontamination history of steam generators. The present work gives a brief overview on the general corrosion state of the heat exchanger tubes of SGs, concerning the long-term effects of the AP-CITROX procedure on the chemical composition and structure of the protective oxide-layer.
{"title":"Comprehensive investigation of the corrosion state and surface properties of the stainless steel tubes of steam generators","authors":"Andrea Szabó Nagy, K. Varga, B. Baja, Z. Németh, Desző Oravetz, Zoltán Hamonnay, E. Kuzmann, J. Schunk, G. Patek","doi":"10.36547/nbc.1131","DOIUrl":"https://doi.org/10.36547/nbc.1131","url":null,"abstract":"Evaluating the water chemistry in the primary circuit and the effect of chemical econtamination \u0000of the heat exchanger tubes performed by the AP-CITROX (AP: alkaline permanganate; CITROX: citric and oxalic acid) procedure at Paks NPP (Hungary), a project dealing with the comprehensive investigation of the general corrosion state of the steam generators (SGs) has been initiated. Owing to the fact that there is no investigation method available for the in-situ monitoring of the inner surfaces of heat exchanger tubes, a research program based on sampling as well as on ex-situ electrochemical (voltammetric) and surface analytical measurements (SEM-EDX, CEMS, XRD, XPS) was developed and elaborated. In the time period of 2000-2008 - within the frame of the above project - 45 stainless steel specimens, cut out from various locations of the steam generators of the Paks NPP were investigated. Based on the measured corrosion characteristics (corrosion rate, thickness and chemical composition of the protective oxide-layer) it was found that these parameters are strongly dependent on the decontamination history of steam generators. The present work gives a brief overview on the general corrosion state of the heat exchanger tubes of SGs, concerning the long-term effects of the AP-CITROX procedure on the chemical composition and structure of the protective oxide-layer.","PeriodicalId":19210,"journal":{"name":"Nova Biotechnologica et Chimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45463093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The presented paper is intended to study the chemical behaviour of combined geogenicanthropogenic uranium content in specific stream sediments. The sampling points have been chosen with respect to the natural conditions in the locality of groundwater outflow from a former uranium mine adit in Považský Inovec mountain range, near Kálnica village. Besides the total uranium determination and physical-chemical characterization of the relevant water- and sediment samples we carried out modified Tessier type sequential fractionation extractions of natural- and artificially contaminated sediment samples after time dependent agitation in air and in the atmosphere of argon. The obtained results have been compared with those fulfilled with montmorillonite K-10. The total uranium concentrations of the relevant groundwater samples as well as of stream sediments have been determined by ICP-MS using HP 4500. The determinations of uranium in extracts have been accomplished according STN757614, utilizing arsenazo III as a selective complex forming reagent for spectrophotometric determination of uranyl-ions at 650 nm. The total uranium concentration of the groundwater outflow and in the sediment taken in its immediate vicinity has been 31.75±0.35 μg dm-3 and 38.0±2.7 μg g-1 respectively. Unlike montmorillonit K-10, in which the carbonate-bound fraction of uranium after 1 week aeration and agitation in argon atmosphere represents 22.8% and 18.6% respectively, uranium in investigated sediments has been present predominantly in carbonate-bound fraction-reaching under similar conditions 38.6% and 26.6%, respectively.
{"title":"Physical-chemical characterization of uranium containing sediments","authors":"L. Závodsḱa, Eva Kosorínová, J. Lesńy, D. Bodiš","doi":"10.36547/nbc.1139","DOIUrl":"https://doi.org/10.36547/nbc.1139","url":null,"abstract":"The presented paper is intended to study the chemical behaviour of combined geogenicanthropogenic uranium content in specific stream sediments. The sampling points have been chosen with respect to the natural conditions in the locality of groundwater outflow from a former uranium mine adit in Považský Inovec mountain range, near Kálnica village. Besides the total uranium determination and physical-chemical characterization of the relevant water- and sediment samples we carried out modified Tessier type sequential fractionation extractions of natural- and artificially contaminated sediment samples after time dependent agitation in air and in the atmosphere of argon. The obtained results have been compared with those fulfilled with montmorillonite K-10. The total uranium concentrations of the relevant groundwater samples as well as of stream sediments have been determined by ICP-MS using HP 4500. The determinations of uranium in extracts have been accomplished according STN757614, utilizing arsenazo III as a selective complex forming reagent for spectrophotometric determination of uranyl-ions at 650 nm. The total uranium concentration of the groundwater outflow and in the sediment taken in its immediate vicinity has been 31.75±0.35 μg dm-3 and 38.0±2.7 μg g-1 respectively. Unlike montmorillonit K-10, in which the carbonate-bound fraction of uranium after 1 week aeration and agitation in argon atmosphere represents 22.8% and 18.6% respectively, uranium in investigated sediments has been present predominantly in carbonate-bound fraction-reaching under similar conditions 38.6% and 26.6%, respectively.","PeriodicalId":19210,"journal":{"name":"Nova Biotechnologica et Chimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46481981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
According to the latest EU regulations it is necessary to cut down the consumption of chemically based pesticides. Several research programmes are focussed on the study of secondary metabolites of plants, which have antimicrobial or antifungal activity against microbial phytopathogens. Other reasons for using of natural biocides are the growth of resistance of phytopathogens against several pesticides; broaden microbial attacks to significant agricultural product for food industry due to the climate changes. The presentation is focussed on the determination of the contents of secondary metabolitesleaves of several cultivars of hop – polyphenols and flavonoids. Methanol crude leaves extracts were tested on biocide effects against selected microbial phytopathogens.
{"title":"Secondary metabolites with antibacterial effects from leaves of different hop cultivars during vegetal periods","authors":"E. Űrgeová, Ľ. Polívka","doi":"10.36547/nbc.1142","DOIUrl":"https://doi.org/10.36547/nbc.1142","url":null,"abstract":"According to the latest EU regulations it is necessary to cut down the consumption of chemically based pesticides. Several research programmes are focussed on the study of secondary metabolites of plants, which have antimicrobial or antifungal activity against microbial phytopathogens. Other reasons for using of natural biocides are the growth of resistance of phytopathogens against several pesticides; broaden microbial attacks to significant agricultural product for food industry due to the climate changes. The presentation is focussed on the determination of the contents of secondary metabolitesleaves of several cultivars of hop – polyphenols and flavonoids. Methanol crude leaves extracts were tested on biocide effects against selected microbial phytopathogens.","PeriodicalId":19210,"journal":{"name":"Nova Biotechnologica et Chimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48058098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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