23 results on '"Chryssoula Drouza"'
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2. Binuclear VsupIV/V/sup, MosupVI/supand ZnsupII/sup- hydroquinonate complexes: Synthesis, stability, oxidative activity and anticancer properties
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Maria, Loizou, Petri, Papaphilippou, Manolis, Vlasiou, Maria, Spilia, Dimitrios, Peschos, Yannis V, Simos, Anastasios D, Keramidas, and Chryssoula, Drouza
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Ions ,Oxidative Stress ,Zinc ,Coordination Complexes ,Water ,Crystallography, X-Ray ,Ligands ,Reactive Oxygen Species ,Mercaptoethanol - Abstract
Since the discovery of the anticancer properties of cis-platin the road for the development of less toxic and more specific metal ion based anticancer drugs has opened. Based on the low toxicity of VsupIV/V/sup, MosupVI/supand ZnsupII/supmetal ions, their binuclear hydroquinonate complexes have been synthesized and their biological activity towards their anticancer properties on various cancerous and non-cancerous cell lines has been evaluated. The new complexes of ZnsupII/supwith the ligands 2,5-bis((bis(pyridin-2-ylmethyl)amino)methyl)benzene-1,4-diol (Hsub2/subbpymah) and 2,2'-(((2,5-dihydroxy-1,4-phenylene)bis(methylene))bis((carboxymethyl)ammoniumdiyl))diacetate (Hsub6/subbicah) have been synthesized and characterized by X-ray crystallography in solid state andsup1/supH NMR in aqueous solution. The binuclear nature of the complexes increases their hydrolytic stability in aqueous solutions at pD 7.0, depending on the metal ion. The most hydrolytic stable VsupV/supand ZnsupII/suphydroquinonate complexes show to activate Osub2/subtowards oxidation of mercaptoethanol in aqueous solutions at physiological pHs. Only the strongest oxidant, the VsupV/supcomplex with bicahsup6-/sup, significantly activates the intracellular radical oxygen species (ROS) generation. Apparently, the mercaptoethanol oxidation experiment vs time can be used as a preliminary experiment for the prediction of the in vitro ROS generation activity of the complexes in aqueous solutions.
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- 2022
3. Insight into the Recent Application of Chemometrics in Quality Analysis and Characterization of Bee Honey during Processing and Storage
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Maria Tarapoulouzi, Monica Mironescu, Chryssoula Drouza, Ion Dan Mironescu, and Sofia Agriopoulou
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Health (social science) ,Plant Science ,Health Professions (miscellaneous) ,Microbiology ,Food Science - Abstract
The application of chemometrics, a widely used science in food studies (and not only food studies) has begun to increase in importance with chemometrics being a very powerful tool in analyzing large numbers of results. In the case of honey, chemometrics is usually used for assessing honey authenticity and quality control, combined with well-established analytical methods. Research related to investigation of the quality changes in honey due to modifications after processing and storage is rare, with a visibly increasing tendency in the last decade (and concentrated on investigating novel methods to preserve the honey quality, such as ultrasound or high-pressure treatment). This review presents the evolution in the last few years in using chemometrics in analyzing honey quality during processing and storage. The advantages of using chemometrics in assessing honey quality during storage and processing are presented, together with the main characteristics of some well-known chemometric methods. Chemometrics prove to be a successful tool to differentiate honey samples based on changes of characteristics during storage and processing.
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- 2023
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4. Binuclear VIV/V, MoVI and ZnII - hydroquinonate complexes: Synthesis, stability, oxidative activity and anticancer properties
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Maria Loizou, Petri Papaphilippou, Manolis Vlasiou, Maria Spilia, Dimitrios Peschos, Yannis V. Simos, Anastasios D. Keramidas, and Chryssoula Drouza
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Inorganic Chemistry ,Biochemistry - Published
- 2022
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5. Traditionally Used Sideritis cypria Post.: Phytochemistry, Nutritional Content, Bioactive Compounds of Cultivated Populations
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Nikolaos Tzortzakis, Helen Skaltsa, Chryssoula Drouza, Ekaterina-Michaela Tomou, Antonios Chrysargyris, and Krystalia Lytra
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0301 basic medicine ,Infusions ,Leaves ,Melittoside ,Phytochemistry ,Iridoid ,medicine.drug_class ,Cultivation ,Agricultural Biotechnology ,leonoside A ,Population ,melittoside ,Flowers ,Lamalboside ,Flavones ,Leonoside A ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Chlorogenic acid ,lamalboside ,medicine ,Pharmacology (medical) ,education ,Original Research ,Pharmacology ,chemistry.chemical_classification ,education.field_of_study ,flowers ,biology ,Traditional medicine ,Agricultural Sciences ,lcsh:RM1-950 ,Phenylethanoid ,biology.organism_classification ,infusions ,Sideritis cypria ,lcsh:Therapeutics. Pharmacology ,030104 developmental biology ,cultivation ,chemistry ,030220 oncology & carcinogenesis ,Sideritis ,leaves - Abstract
The authors are grateful to the Cyprus University of Technology Open Access Author Fund. Sideritis species are recognized as important medicinal plants and their commercial demand is continuously on the rise both in the European and in the global market. Consequently, the cultivation of Sideritis species has been occurred to successfully meet the need for mass production of high-quality plant material. The present study was undertaken in order to investigate the chemical composition of cultivated S. cypria. Infusions of flowers and leaves were prepared separately, according to the European Medicine Agency (EMA) monograph. The infusion of the flowers revealed the presence of four flavones, isoscutellarein-7-O-[6'″-O-acetyl-β-D-allopyranosyl-(1→2)-β-D-glucopyranoside, its 4'-O-methyl-derivative, 4'-O-methyl-hypolaetin-7-O-[6'″-O-acetyl-β-D-allopyranosyl-(1→2)-β-D-glucopyranoside, and isoscutellarein-7-O-[6'″-O-acetyl-β-D-allopyranosyl-(1→2)]-6″-O-acetyl-β-D-glucopyranoside; four phenylethanoid glucosides, acteoside, leucosceptoside A, lamalboside, and leonoside A; one iridoid, melittoside, and one phenolic acid, chlorogenic acid, while the infusion of the leaves of the same population afforded the same first two flavones; five phenylethanoid glucosides, acteoside, leucosceptoside A, lavandulifolioside, leonoside A, and lamalboside; melittoside and chlorogenic acid. The structural elucidation of the isolated compounds was undertaken by high-field NMR spectroscopy. Moreover, the essential oils of the flowers and leaves were studied by GC-MS, separately. In addition, the mineral, bioactive compounds, protein and carbohydrate contents were evaluated for both plant materials.
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- 2020
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6. Enhancement of the Anti-Inflammatory Activity of NSAIDs by Their Conjugation with 3,4,5-Trimethoxybenzyl Alcohol
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Paraskevi Tziona, Panagiotis Theodosis-Nobelos, Georgios Papagiouvannis, Anthi Petrou, Chryssoula Drouza, and Eleni A. Rekka
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Cyclooxygenase 2 Inhibitors ,Anti-Inflammatory Agents, Non-Steroidal ,Organic Chemistry ,Anti-Inflammatory Agents ,non steroidal anti-inflammatory drugs ,anti-inflammatory derivatives ,cyclooxygenase inhibition ,molecular docking ,lipoxygenase inhibition ,Pharmaceutical Science ,Ibuprofen ,Carrageenan ,Rats ,Analytical Chemistry ,Molecular Docking Simulation ,Cyclooxygenase 2 ,Ketoprofen ,Chemistry (miscellaneous) ,Drug Discovery ,Cyclooxygenase 1 ,Animals ,Edema ,Molecular Medicine ,Amino Acids ,Physical and Theoretical Chemistry - Abstract
The synthesis of derivatives of three nonspecific COX-1 and COX-2 inhibitors, ibuprofen, ketoprofen, naproxen is presented. These acids were connected via an amide bond with an amino acid (L-proline, L-tyrosine, and beta-alanine) used as a linker. The amino acid carboxylic group was esterified with 3,4,5 trimethoxybenzyl alcohol. The activity of the novel derivatives was examined in vivo on carrageenan-induced inflammation, and in vitro, as cyclooxygenase and lipoxygenase inhibitors. It was found that the new compounds were more potent anti-inflammatory agents than the parent drugs. Thus, the ibuprofen (21) and ketoprofen (16) derivatives reduced rat paw edema by 67 and 91% (the reduction by the relevant NSAIDs was 36 and 47%, respectively). They inhibited COX-2 more than the starting drugs (21 by 67%, ibuprofen 46%, 19 by 94%, ketoprofen 49%). Docking of compounds on the active sites of COX-1 and COX-2 reflects their in vitro activity. Thus, 19 adopts an unfavorable orientation for COX-1 inhibition, but it binds effectively in the binding pocket of COX-2, in agreement with the absence of activity for COX-1 and the high inhibition of COX-2. In conclusion, the performed structural modifications result in the enhancement of the anti-inflammatory activity, compared with the parent NSAIDs.
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- 2022
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7. Investigation of Phenols Activity in Early Stage Oxidation of Edible Oils by Electron Paramagnetic Resonance and 19F NMR Spectroscopies Using Novel Lipid Vanadium Complexes As Radical Initiators
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Marios Stylianou, Chryssoula Drouza, Anthi Dieronitou, and Ioanna Hadjiadamou
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Agricultural Biotechnology ,Radical ,Analytical chemistry ,Vanadium complexes ,Vanadium ,chemistry.chemical_element ,Fluorine-19 NMR ,010402 general chemistry ,01 natural sciences ,Spectral line ,law.invention ,α-tocopheryl radical ,chemistry.chemical_compound ,Prooxidant/antioxidant ,law ,Phenols ,Spectroscopy ,Electron paramagnetic resonance ,Maximum intensity ,Agricultural Sciences ,010405 organic chemistry ,Chemistry ,General Chemistry ,0104 chemical sciences ,General Agricultural and Biological Sciences ,Olive oil ,EPR/NMR ,Nuclear chemistry - Abstract
A novel dynamic method for the investigation of the phenols activity in early stage oxidation of edible oils based on the formation of a-tocopheryl radicals initiated by oil-soluble vanadium complexes is developed. Two new vanadium complexes in oxidation states V and IV were synthesized by reacting 2,2'-((2-hydroxyoctadecyl)azanediyl)bis(ethan-1-ol) (C18DEA) with [VO(acac)(2)] and 1-(bis(pyridin-2-ylmethyl)amino)octadecan-2-ol (C18DPA) with VOCl2. Addition of a solution of either complex in edible oils resulted in the formation of alpha-tocopheryl radical, which was monitored by electron paramagnetic resonance (EPR) spectroscopy. The intensity of the alpha-tocopheryl signal in the EPR spectra was measured versus time. It was found that the profile of the intensity of the a-tocopheryl signal versus time depends on the type of oil, the phenolic content, and the storage time of the oil. The time interval until the occurrence of maximum peak intensity be reached (t(m).), the height of the maximum intensity, and the rate of the quenching of the alpha-tocopheryl radical were used for the investigation of the mechanism of the edible oils oxidation. F-19 NMR of the F-19 labeled phenolic compounds (through trifluoroacetate esters) and radical trap experiments showed that the vanadium complexes in edible oil activate the one electron reduction of dioxygen to superperoxide radical. Superperoxide reacts with the lipids to form alkoperoxyl and alkoxyl lipid radicals, and all these radicals react with the phenols contained in oils.
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- 2017
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8. Synthesis of vitamin E and aliphatic lipid vanadium(IV) and (V) complexes, and their cytotoxic properties
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George Papanastasiou, Irida Dhima, Anastasios D. Keramidas, Spyridon Ch. Karkabounas, Manolis Vlasiou, Vasilios Ragos, Smaragda Spanou, Chryssoula Drouza, Ioanna Hadjiadamou, Yannis V. Simos, and Evangelos Kontargiris
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Antioxidant ,Cytotoxic ,Agricultural Biotechnology ,Radical ,medicine.medical_treatment ,Vanadium ,chemistry.chemical_element ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Medicinal chemistry ,law.invention ,Inorganic Chemistry ,chemistry.chemical_compound ,Coordination Complexes ,law ,Neoplasms ,Amphiphile ,medicine ,Humans ,Vitamin E ,Chelation ,Electron paramagnetic resonance ,Tocopherol ,Cytotoxins ,Agricultural Sciences ,010405 organic chemistry ,Chemistry ,Radicals ,Lipids ,0104 chemical sciences ,HEK293 Cells ,Dipicolylamine ,Lipophilicity ,HeLa Cells - Abstract
Novel vitamin E chelate derivatives and their VIV/V complexes have been synthesized and characterized, and their anticancer properties have been evaluated. The new complexes have been designed to exhibit enhanced cytotoxicity by combining high lipophilicity with the properties of vanadium to induce the formation of reactive oxygen species (ROS). In particular, the β-tocopherol derivatives with iminodiethanol (β-tocDEA) and dipicolylamine (β-tocDPA) as well their VV and VIV complexes, [VVO(β-tocDEA] and [VIVO(β-tocDPA] have been synthesized and characterized by Nuclear Magnetic Resonance (NMR), Ultra Violet-Visible (UV–Vis) and Electron Paramagnetic Resonance (EPR) spectroscopies. Although the β-tocopherol compounds exhibit antioxidant activity their complexes induce formation of radicals. In addition, two vanadium amphiphilic complexes of 2,2′-((2-hydroxyoctadecyl)azanediyl)bis(ethan-1-ol) (C18DEA) and 1-(bis(pyridin-2-ylmethyl)amino)octadecan-2-ol (C18DPA) known to activate O2 and produce ROS were synthesized and characterized (C. Drouza, A. Dieronitou, I. Hadjiadamou, M. Stylianou, J. Agric. Food. Chem., vol. 65, 2017, pp. 4942–4951). The four amphiphilic vanadium complexes exhibit enhanced hydrolytic stability. All compounds found to be cytotoxic for cancer cells exhibiting activity similar or higher to cis-platin.
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- 2020
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9. 19F NMR for the speciation and quantification of the OH-molecules in complex matrices
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Chryssoula Drouza and Manolis Vlasiou
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Complex matrix ,19f nmr spectroscopy ,Chemistry ,General Chemical Engineering ,General Engineering ,Analytical chemistry ,High resolution ,Nuclear magnetic resonance spectroscopy ,Fluorine-19 NMR ,OH-molecules ,Analytical Chemistry ,NMR spectroscopy ,Computational chemistry ,Chemical Sciences ,Genetic algorithm ,Molecule ,Natural Sciences - Abstract
A novel method for the speciation and quantification of the minor OH-molecules in complex matrices in a one pot experiment based on 19F NMR spectroscopy is demonstrated. The method exerts high resolution and sensitivity comparable with conventional methods and gives reliable results when directly applied to edible oils.
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- 2015
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10. Chemometric characterization of virgin olive oils of the two major Cypriot cultivars based on their fatty acid composition
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Chryssoula Drouza, Georgios Menexes, and Angelina Kritioti
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Cypriot virgin olive oil ,Linoleic acid ,Gas Chromatography-Mass Spectrometry ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Olea ,Botany ,Variety ,GC–MS ,Cultivar ,Food science ,Chemometrics ,Olive Oil ,chemistry.chemical_classification ,Flame Ionization ,Agricultural Sciences ,Altitude ,Fatty Acids ,food and beverages ,Fatty acid ,Microclimate ,04 agricultural and veterinary sciences ,Agriculture Forestry and Fisheries ,040401 food science ,FAME ,chemistry ,Fruit ,Cyprus ,lipids (amino acids, peptides, and proteins) ,Fatty acid composition ,Gas chromatography–mass spectrometry ,GC-FID ,Food Analysis ,Food Science ,Olive oil ,Polyunsaturated fatty acid - Abstract
The effects of the geographical region and the botanical origin of olive oils on the profile of fatty acids isolated from monovarietal virgin olive oils from Cyprus were investigated, in order to establish, for the first time, promising models for authentication and classification of monovarietal virgin olive oils produced on the island. The two dominant Cypriot olive cultivars, Cypriot (ladoelia), and Koroneiki (lianolia), were analyzed for fatty acid composition by GC/FID after preparation of Fatty Acid Methyl Esters from olive oil, using a cold esterification method. The data obtained were analyzed statistically using multivariate and univariate ANOVA, principal components analysis (PCA) and hierarchical cluster analysis. Results showed that the olive oils can be separated into two distinct groups using the FAME data bank obtained from 225 samples. Significant differences in the proportion of some variables such as polyunsaturated linoleic acid, and the ratio C18:1/C18:2 from oils of different varieties and geographical regions were detected. The ratios C18:1/C18:2 and MUFA/PUFA, as well SFA, ω-9 and PUFA showed the higher discriminant power based on the cultivar.
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- 2017
11. Investigation of Phenols Activity in Early Stage Oxidation of Edible Oils by Electron Paramagnetic Resonance and
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Chryssoula, Drouza, Anthi, Dieronitou, Ioanna, Hadjiadamou, and Marios, Stylianou
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Free Radicals ,Phenols ,alpha-Tocopherol ,Electron Spin Resonance Spectroscopy ,Plant Oils ,Vanadium ,Lipids ,Oxidation-Reduction - Abstract
A novel dynamic method for the investigation of the phenols activity in early stage oxidation of edible oils based on the formation of α-tocopheryl radicals initiated by oil-soluble vanadium complexes is developed. Two new vanadium complexes in oxidation states V and IV were synthesized by reacting 2,2'-((2-hydroxyoctadecyl)azanediyl)bis(ethan-1-ol) (C18DEA) with [VO(acac)
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- 2017
12. Saccharomyces cerevisiae and Oenococcus oeni immobilized in different layers of a cellulose/starch gel composite for simultaneous alcoholic and malolactic wine fermentations
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Carmen Berbegal, Athanasios A. Koutinas, Chryssoula Drouza, Poonam Singh Nee Nigam, Nathalia Camacho, Sergi Ferrer, Argyro Bekatorou, and Ioannis Servetas
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Wine ,Bioengineering ,Saccharomyces cerevisiae ,Ethanol fermentation ,Applied Microbiology and Biotechnology ,Biochemistry ,Immobilization ,chemistry.chemical_compound ,Malolactic fermentation ,Bioreactor ,Food science ,Oenococcus oeni ,biology ,Agricultural Sciences ,Chemistry ,food and beverages ,equipment and supplies ,biology.organism_classification ,Lactic acid ,Composite biocatalyst ,Other Agricultural Sciences ,Fermentation ,Malic acid - Abstract
The production of a two-layer composite biocatalyst for immobilization of two different microorganisms for simultaneous alcoholic and malolactic fermentation (MLF) of wine in the same bioreactor is reported. The biocatalyst consisted of a tubular delignified cellulosic material (DCM) with entrapped Oenococcus oeni cells, covered with starch gel containing the alcohol resistant and cryotolerant strain Saccharomyces cerevisiae AXAZ-1. The biocatalyst was found effective for simultaneous low temperature alcoholic fermentation resulting to conversion of malic acid to lactic acid in 5 days at 10 °C. Improvement of wine quality compared with wine fermented with S. cerevisiae AXAZ-1 immobilized on DCM was attributed to MLF as well as to increased ester formation and lower higher alcohols produced at low fermentation temperatures (10 °C) as shown by GC and headspace SPME GC/MS analysis. Scanning electron microscopy showed that the preparation of a three-layer composite biocatalyst is also possible. The significance of such composite biocatalysts is the feasibility of two or three bioprocesses in the same bioreactor, thus reducing production cost in the food industry
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- 2013
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13. Optimization of potassium fertilization/nutrition for growth, physiological development, essential oil composition and antioxidant activity of Lavandula angustifolia Mill
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Nikos Tzortzakis, Antonios Chrysargyris, and Chryssoula Drouza
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0106 biological sciences ,Antioxidant ,medicine.medical_treatment ,Potassium ,Soil Science ,chemistry.chemical_element ,Plant Science ,soilless culture ,Biology ,01 natural sciences ,Antioxidants ,essential oil ,law.invention ,Human fertilization ,law ,Botany ,medicine ,Essential oil ,Lavandula angustifolia ,04 agricultural and veterinary sciences ,minerals ,chemistry ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Composition (visual arts) ,Agronomy and Crop Science ,010606 plant biology & botany - Abstract
Lavandula angustifolia (Mill.) is a medicinal plant of great importance with a variety of applications in perfume and pharmaceutical industries or landscaping, but only limited information is available about its response to potassium supplementation. This experiment was conducted in order to determine the effects of potassium (K: 275-300-325-350-375 mg L-1) levels on the morphological and biochemical characteristics of lavender grown hydroponically. Results showed that K levels affected plant growth, mainly the root development while no differences were found for leaf chlorophyll content and stomatal conductance. Essential oil yield increased in the 300 mg L-1 in comparison to 275 or 325-375 mg L-1 of K application. The middle ranged K levels (300-325-350 mg L-1) enhanced leaf content in total phenols, flavonoids and antioxidant activity (DPPH, FRAP). Lipid peroxidation content (MDA) employed as damage index, was lower in the 325 mg L-1 of K treatment. No differences were observed in antioxidant enzymes (SOD, CAT, APX) activity and H2O2 content among K applications. The main constituents of leaves essential oil (1,8-cineole, borneol, camphor, α-terpineol, myrtenal) and mineral accumulation were affected by K treatments. Lavender grown in 300 mg L-1 of K was appropriate for the essential oil uses/production while the 325 mg L-1 of K were more appropriate for lavender cultivation for fresh and dry matter uses.
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- 2017
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14. Synthesis, spectroscopic, structural and magnetic studies of new binary Cr(III)–citrate pH-specific structural variants from aqueous media
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C. Gabriel, Chryssoula Drouza, Nikolia Lalioti, Catherine P. Raptopoulou, and Athanasios Salifoglou
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Aqueous solution ,Ligand ,Inorganic chemistry ,Variants ,chemistry.chemical_element ,Magnetic susceptibility ,Inorganic Chemistry ,Chromium ,Crystallography ,chemistry.chemical_compound ,Deprotonation ,Octahedron ,chemistry ,Chemical Sciences ,Materials Chemistry ,Citrates ,Binary system ,Physical and Theoretical Chemistry ,Natural Sciences ,Citric acid ,Chromium--toxicity ,X-ray telescopes - Abstract
In an attempt to understand the aqueous interactions of Cr(III) with the low molecular mass physiological ligand citric acid, the pH-specific synthesis in the binary Cr(III)–citrate system was pursued, leading to the new complexes Na3[Cr(C6H5O7)2]·8.5H2O (1) and (Hdmphen)6[Cr(C6H5O7)2]·(NO3)3·14H2O (2). Complexes 1 and 2 were characterized by elemental analysis, spectroscopic, structural, thermal, and magnetic susceptibility studies. The structures of 1 and 2 reveal a mononuclear octahedral complex of Cr(III) with two citrate ligands bound to it. Albeit of the same deprotonation state, the disposition of the two citrate ligands with respect to Cr(III) differs between 1 and 2 in the solid state, thus reflecting the presence of pH-structural variants in the requisite binary system. This conformational difference is lifted in aqueous solution, thus providing (a) comparative information on the distribution and diversity of species in the binary Cr(III)–citrate system, and (b) insight into the nature of interactions developing in the binary Cr(III)–hydroxycarboxylate systems in abiotic and biological applications.
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- 2009
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15. pH-Specific synthetic chemistry, and spectroscopic, structural, electrochemical and magnetic susceptibility studies in binary Ni(II)-(carboxy)phosphonate systems
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Marianna Dakanali, Nikolia Lalioti, Athanasios Salifoglou, Catherine P. Raptopoulou, Melita Menelaou, and Chryssoula Drouza
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Aqueous solution ,Biological systems ,Inorganic chemistry ,chemistry.chemical_element ,Phosphonate ,Chemical synthesis ,Magnetic susceptibility ,Inorganic Chemistry ,Metal ,chemistry.chemical_compound ,Crystallography ,Nickel ,chemistry ,visual_art ,Chemical Sciences ,Materials Chemistry ,visual_art.visual_art_medium ,Molecule ,Phosphonates ,Physical and Theoretical Chemistry ,Cyclic voltammetry ,Natural Sciences ,X-ray telescopes - Abstract
Nickel can play numerous roles in biological systems and in advanced abiotic materials. Supporting the diverse roles of Ni(II) in biological media are, among others, metal ion binding amino acids, their variably phosphorylated forms and/or exogenously administered organophosphonate drug substrates. In an effort to comprehend the aqueous chemistry of interactions between Ni(II) and organophosphonate substrates, research efforts were launched involving the ligands imino bis(methylenephosphonic acid) (H4IDA2P), H2O3P–CH2– NH 2 + –CH2–PO3H−, and N-(phosphonomethyl)glycine (glyphosate–H3IDAP), HOOC–CH2– NH 2 + –CH2–PO3H−. pH-Specific reactions of Ni(II) with H4IDA2P and H3IDAP led to the isolation of [Ni(C2H8O6NP2)2(H2O)2] (1) and [Ni(OOC–CH2–NH–CH2–PO3H)2]·[Ni(H2O)6]·3.3H2O (2), respectively. Compound 1 was characterized by analytical, spectroscopic techniques (UV–Vis, FT-IR), cyclic voltammetry, magnetic susceptibility measurements and X-ray crystallography. Compound 2 was characterized by elemental analysis, FT-IR spectroscopy, and X-ray crystallography. The structures of 1 and 2 reveal mononuclear octahedral Ni(II) assemblies bound by H3IDA2P− and water (1), and glyphosate (HIDAP2−) and water molecules (2), respectively. Magnetic susceptibility studies on 1 support the presence of high-spin octahedral Ni(II) in an oxygen environment, consistent with X-ray crystallography. The collective physicochemical features of the discrete Ni(II) assemblies in both species (a) shed light on aqueous binary Ni(II)–phosphoderivative interactions potentially influencing cellular physiology or toxicity, and (b) define the fundamental properties essential for the employment of such species in advanced materials synthesis and applications.
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- 2009
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16. Synthesis, Structure, and Solution Dynamics of UO22+−Hydroxy Ketone Compounds [UO2(ma)2(H2O)] and [UO2(dpp)(Hdpp)2(H2O)]ClO4 [ma = 3-Hydroxy-2-methyl-4-pyrone, Hdpp = 3-Hydroxy-1,2-dimethyl-4(1H)-pyridone]
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Anastasios D. Keramidas, Volker Gramlich, Ioannis Pashalidis, Chryssoula Drouza, and Michael P. Sigalas
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chemistry.chemical_classification ,Denticity ,Ketone ,Chemistry ,Stereochemistry ,Ligand ,Crystal structure ,Medicinal chemistry ,Inorganic Chemistry ,Pentagonal bipyramidal molecular geometry ,Intramolecular force ,Proton NMR ,Physical and Theoretical Chemistry ,Monoclinic crystal system - Abstract
Reaction of [UO(2)(NO(3))(2)] with the hydroxy ketones 3-hydroxy-2-methyl-4-pyrone (Hma) and 3-hydroxy-1,2-dimethyl-4(1H)-pyridone (Hdpp) in aqueous acidic solutions (pH approximately 3) yields the compounds [UO(2)(ma)(2)(H(2)O)].H(2)O (1.H(2)O) and [UO(2)(dpp)(Hdpp)(2)(H(2)O)]ClO(4) (2), respectively. X-ray diffraction shows that the geometry around the metal ion in both complexes is pentagonal bipyramid. Uranium ion in the crystal structure of 1 were found to be ligated with two chelate ma(-) groups and one unidentate H(2)O molecule (C coordination mode) at the equatorial plane, while in 2 with two single-bonded Hdpp there were one chelate dpp(-) and one H(2)O molecule (P coordination mode). Crystal data (Mo Kalpha; 293(2) K) are as follows: (1) monoclinic space group C2/c, a = 14.561(7) A, b = 14.871(9) A, c = 7.250(4) A, beta = 95.40(4) degrees , Z = 4; (2) monoclinic space group P2(1)/c, a = 19.080(2) A, b = 9.834(1) A, c = 15.156(2) A, beta = 104.62(1) degrees , Z = 4. (1)H NMR measurements indicate that complex 2 retains its structure in CD(3)CN solution; however, in DMSO-d(6) both complexes adopt the C structure. Line-shape analysis for the (1)H NMR peaks of 2 at various temperatures shows a fast intramolecular exchange process between the chelate dpp(-) and one of the single bonded Hdpp ligands and one slower exchange between all three ligands. The activation parameters and the decrease of the exchange rate by replacing unidentate ligand with DMSO indicate the dissociation of the unidentate ligand as the rate-determining step for the former exchange. Density functional calculations (DFT) support this mechanism and give a quantitative interpretation of the electronic structure of the two ligands and the geometries adopted by the complexes.
- Published
- 2004
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17. Investigation on uranyl interaction with bioactive ligands. Synthesis and structural studies of the uranyl complexes with glycine and N-(2-mercaptopropionyl)glycine
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A. Terzis, Ioannis Pashalidis, Anastasios D. Keramidas, Chryssoula Drouza, Maria P. Rikkou, and Catherine P. Raptopoulou
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Denticity ,Carboxylic acids ,Agricultural Sciences ,Agricultural Biotechnology ,Glycine ,chemistry.chemical_element ,Crystal structure ,Uranium ,Ligands ,Uranyl ,Solid state ,NMR spectra database ,chemistry.chemical_compound ,Crystallography ,Other Agricultural Sciences ,chemistry ,Atom ,Carboxylate ,Physical and Theoretical Chemistry ,Infrared spectroscopy ,Nuclear magnetic resonance spectroscopy ,X-ray crystallography ,Nuclear chemistry - Abstract
Summary Three new uranium(VI) compounds have been prepared with glycine (Hgly), N-(2-mercaptopropionyl)glycine (Hmpg) and 2,2′-dithiobis(N-propionylglycine) (tpg). The crystal structure of [UO2(Hgly)2Cl2] has been solved, revealing the uranium atom to be seven-co-ordinated. The two zwitterionic glycines are coordinated to uranium atom by the carboxylate groups, one in a monodentate and the other in a bidentate mode. Solid state studies and low temperature 1H, 13C, 2D COSY and HMQC solution NMR spectra of the [UO2(mpg)(CH3COO)], show that mpg coordinates uranium atom by the carboxylate group.
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- 2002
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18. σ-Bonded p-Dioxolene Transition Metal Complexes
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Chryssoula Drouza, Marios Stylianou, and Anastasios D. Keramidas
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chemistry.chemical_compound ,Semiquinone ,Hydroquinone ,chemistry ,Metal K-edge ,Metal ions in aqueous solution ,Polymer chemistry ,Dihydrogen complex ,Metal aquo complex ,Redox ,Quinone - Abstract
Metal ions are known to lie in close proximity with these species in biological systems, thus resulting in immediate interaction. The two coupled, metal and organic redox centers have been found to participate in several biological processes such as, the oxidative maintenance of biological amine levels, (Klinman, 1996) tissue (collagen and elastin) formation, (Klinman, 1996) photosynthesis (Calvo, et al., 2000) and respiration (Iwata, et al., 1998). Although the crystal structures of many of these enzymes have been solved, the role of the metal ions in these reactions is still controversial. From another point of view, quinonoid metal complexes exhibit rich redox, magnetic and photochemical properties and thus can underpin key technological advances in the areas of energy storage, sensors, catalysis and “smart materials” (Evangelio & Ruiz-Molina, 2005; Stylianou, et al., 2008). Metal ions interact with hydroquinone systems, through σ-bonding to the oxygen atoms and/or through π-bonding to the carbocyclic ring. The structurally characterized σ-bonded hydroquinone metal complexes are surprisingly limited. Structures of metal ions with psemiquinones and quinones are even rarer, mainly due to the absence of a chelate coordination site in simple p-(hydro/semi)quinone and the low pK values of the semiquinone and quinone oxygen atoms. A strategy to synthesize stable metal complexes with hydroquinone species is to use substituted hydroquinones in o-position with substituents containing one or more donor atoms, enabling in this way the metal atom to
- Published
- 2011
- Full Text
- View/download PDF
19. Scale-up of extremely low temperature fermentations of grape must by wheat supported yeast cells
- Author
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Panagiotis Kandylis, Athanasios A. Koutinas, Argyro Bekatorou, and Chryssoula Drouza
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Environmental Engineering ,Scale-up ,Bioengineering ,Wine ,Saccharomyces cerevisiae ,Gas Chromatography-Mass Spectrometry ,Catalysis ,Immobilization ,Bioreactors ,Bioreactor ,Vitis ,Waste Management and Disposal ,Solid Phase Microextraction ,Triticum ,Winemaking ,Waste Products ,Volatile Organic Compounds ,Chromatography ,Sweetness of wine ,Renewable Energy, Sustainability and the Environment ,Chemistry ,food and beverages ,Esters ,General Medicine ,Biological Sciences ,equipment and supplies ,Yeast ,Cold Temperature ,Kinetics ,Alcohols ,Wheat ,Fermentation ,Biocatalysis ,Gas chromatography ,GC-MS ,Natural Sciences ,Laboratories - Abstract
A new biocatalyst was prepared by immobilization of Saccharomyces cerevisiae AXAZ-1 yeast cells on whole wheat grains. This biocatalyst was used for 30 repeated batch fermentations of glucose and grape must at various temperatures. The biocatalyst retained its operational stability for a long period and it was proved capable to produce dry wines of fine clarity even at extremely low temperatures (5 degrees C). After the completion of these fermentations the new biocatalyst was used in a scale-up system of 80 L for wine making at ambient (20 degrees C) and extremely low temperatures (2 degrees C). The scale-up process did not affect the fermentative ability of biocatalyst, even at low temperatures, while the produced wines had almost the same improved aromatic profile compare to free cells as revealed by GC and GC-MS analyses. More specifically the results showed that both systems with immobilized cells (laboratory scale and 80 L bioreactor) increased the formation of esters and produced wines with improved aromatic profile compared to those with free cells. Finally an increase in the percentages of total esters and a decrease in those of higher alcohols was observed in lower fermentation temperatures.
- Published
- 2010
20. pH-Dependent syntheses, structural and spectroscopic characterization, and chemical transformations of aqueous Co(II)-quinate complexes: an effort to delve into the structural speciation of the binary Co(II)-quinic acid system
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Chryssoula Drouza, C. Mateescu, Athanasios Salifoglou, A. Konstantopai, Melita Menelaou, Hong Zhao, and Nikolia Lalioti
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Models, Molecular ,Spectrometry, Mass, Electrospray Ionization ,Chemical structure ,media_common.quotation_subject ,Quinic Acid ,chemistry.chemical_element ,Infrared spectroscopy ,Crystallography, X-Ray ,Inorganic Chemistry ,Metal ,chemistry.chemical_compound ,Magnetics ,Computational chemistry ,Spectroscopy, Fourier Transform Infrared ,Organometallic Compounds ,Organic chemistry ,Physical and Theoretical Chemistry ,X-ray crystallography ,media_common ,Aqueous solution ,Molecular Structure ,Magnetism ,Methodology ,Electron Spin Resonance Spectroscopy ,Temperature ,food and beverages ,Water ,Quinic acid ,Cobalt ,Hydrogen-Ion Concentration ,Chemistry ,Speciation ,chemistry ,visual_art ,Chemical Sciences ,visual_art.visual_art_medium ,Spectrophotometry, Ultraviolet ,Natural Sciences - Abstract
Cobalt(II) is an essential metal ion, which can react with biologically relevant substrates in aqueous media, affording discrete soluble forms. D-(-)-quinic acid is a representative metal ion binder, capable of promoting reactions with Co(II) under pH-specific conditions, leading to the isolation of the new species K[Co(C(7)H(11)O(6))(3)] x 3 CH(3)CH(2)OH (1), Na[Co(C(7)H(11)O(6))(3)] x 3 CH(3)CH(2)OH x 2.25 H(2)O (2), and [Co(C(7)H(11)O(6))(2)(H(2)O)(2)] x 3 H(2)O (3). Compounds 1-3 were characterized by elemental analysis, spectroscopic techniques (Fourier-transform infrared, UV-visible, electron paramagnetic resonance (EPR), electrospray ionization mass spectrometry), magnetic studies, and X-ray crystallography. Compound 1 crystallizes in the cubic space group P2(1)3, with a = 15.3148(19) A, V = 3592.0(8) A(3), and Z = 4. Compound 2 crystallizes in the orthorhombic space group P2(1)2(1)2(1), with a = 14.9414(8) A, b = 15.9918(9) A, c = 16.0381(9) A, V = 3832.1(4) A(3), and Z = 4. Compound 3 crystallizes in the monoclinic space group P2(1)/m, with a = 13.2198(10) A, b = 5.8004(6) A, c = 15.3470(12) A, beta = 108.430(7), V = 1116.45(17) A(3), and Z = 4. The lattices in 1-3 reveal the presence of mononuclear Co(II) units bound exclusively to quinate (1 and 2) or quinate and water ligands (3), thus projecting the unique chemical reactivity in each investigated system and suggesting that 3 is an intermediate in the synthetic pathway leading to 1 and 2. The octahedral sites of Co(II) are occupied by oxygens, thereby reflecting the nature of interactions between the divalent metal ion and quinic acid. The magnetic and EPR data on 1 and 3 support the presence of a high-spin octahedral Co(II) in an oxygen environment, having a ground state with an effective spin of S = 1/2. The significance of 3 is further reflected into the aqueous speciation of the binary Co(II)-quinic acid system, in which 3 appears as a competent participant linked to the solid state species 1. The physicochemical profiles of 1-3, in the solid state and in solution, earmark the importance of aqueous structural speciation, which projects chemical reactivity pathways in the binary Co(II)-quinate system, involving soluble Co(II) forms emerging through interactions with low molecular mass O-containing physiological substrates, such as quinic acid.
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- 2009
21. Synthesis, structure, and solution dynamics of UO22+-hydroxy ketone compounds [UO2(ma)2(H2O)] and [UO2(dpp)(Hdpp)2(H2O)]ClO4 [ma = 3-hydroxy-2-methyl-4-pyrone, Hdpp = 3-hydroxy-1,2-dimethyl-4(1H)-pyridone]
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Chryssoula, Drouza, Volker, Gramlich, Michael P, Sigalas, Ioannis, Pashalidis, and Anastasios D, Keramidas
- Abstract
Reaction of [UO(2)(NO(3))(2)] with the hydroxy ketones 3-hydroxy-2-methyl-4-pyrone (Hma) and 3-hydroxy-1,2-dimethyl-4(1H)-pyridone (Hdpp) in aqueous acidic solutions (pH approximately 3) yields the compounds [UO(2)(ma)(2)(H(2)O)].H(2)O (1.H(2)O) and [UO(2)(dpp)(Hdpp)(2)(H(2)O)]ClO(4) (2), respectively. X-ray diffraction shows that the geometry around the metal ion in both complexes is pentagonal bipyramid. Uranium ion in the crystal structure of 1 were found to be ligated with two chelate ma(-) groups and one unidentate H(2)O molecule (C coordination mode) at the equatorial plane, while in 2 with two single-bonded Hdpp there were one chelate dpp(-) and one H(2)O molecule (P coordination mode). Crystal data (Mo Kalpha; 293(2) K) are as follows: (1) monoclinic space group C2/c, a = 14.561(7) A, b = 14.871(9) A, c = 7.250(4) A, beta = 95.40(4) degrees , Z = 4; (2) monoclinic space group P2(1)/c, a = 19.080(2) A, b = 9.834(1) A, c = 15.156(2) A, beta = 104.62(1) degrees , Z = 4. (1)H NMR measurements indicate that complex 2 retains its structure in CD(3)CN solution; however, in DMSO-d(6) both complexes adopt the C structure. Line-shape analysis for the (1)H NMR peaks of 2 at various temperatures shows a fast intramolecular exchange process between the chelate dpp(-) and one of the single bonded Hdpp ligands and one slower exchange between all three ligands. The activation parameters and the decrease of the exchange rate by replacing unidentate ligand with DMSO indicate the dissociation of the unidentate ligand as the rate-determining step for the former exchange. Density functional calculations (DFT) support this mechanism and give a quantitative interpretation of the electronic structure of the two ligands and the geometries adopted by the complexes.
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- 2004
22. p-Hydroquinone-metal compounds: synthesis and crystal structure of two novel VV-p-hydroquinonate and VIV-p-semiquinonate species
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Vagelis Tolis, Volker Gramlich, Aris Terzis, Michael P. Sigalas, Anastasios D. Keramidas, Chryssoula Drouza, Cathrine P. Raptopoulou, and Themistoklis A. Kabanos
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Chemical structure ,Agricultural Biotechnology ,Hydroquinone ,Crystal structure ,Quinone--Derivatives ,Chemical reaction ,Catalysis ,Metal ,chemistry.chemical_compound ,Ab initio quantum chemistry methods ,Chemical reactions ,Materials Chemistry ,Agricultural Sciences ,Metals and Alloys ,General Chemistry ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Quinone ,Crystallography ,Other Agricultural Sciences ,chemistry ,visual_art ,Ceramics and Composites ,visual_art.visual_art_medium ,Derivative (chemistry) - Abstract
Reaction of the p-hydroquinone derivative H2Na4bicah.4H2O with either VIVOSO(4).3H2O and NaVVO3 in equivalent quantities or with NaVVo3 yields the tetranuclear VIVO2+ macrocycle-semiquinonate compound Na6[(VIVO)4-(mu2-O)2[mu2-bicas.(-5)-N,O,O,O]2].Na2SO(4).20H2O (1.Na2SO(4).20H2O) and the dinuclear cis-VVO2(+)-hydroquinone species Na4[(VVO2)2[mu2-bicah(-6)-N,O,O,O]].11H2O (2.11H2O) respectively. Compounds 1.Na2SO(4).20H2O and 2.11H2O were characterized by X-ray structure analysis and ab initio calculations.
- Published
- 2002
23. Bioethanol production from brewers’ solid wastes by co-immobilized co-culture Aspergillus awamori–Saccharomyces cerevisiae
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Chryssoula Drouza, Athanasios A. Koutinas, Konstantina Tsaousi, and Sofia Nikolaou
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biology ,Fossil fuels ,Chemistry ,Applied Microbiology ,Saccharomyces cerevisiae ,Biomedical Engineering ,Bioethanol ,Bioengineering ,Solid wastes ,biology.organism_classification ,Biochemistry ,Biofuel ,Chemical Sciences ,Food science ,Natural Sciences ,Molecular Biology ,Aspergillus awamori ,Biotechnology - Abstract
The signing of the Kyoto Protocol (KP) in 1997 commands the substitution of fossil fuels by alternative fuels for the reduction of the emission of greenhouse gases. The Environmental strategy (EC, 1997) necessitated the increase of energy production from renewables. Utilization of Brewers’ Spent Grain (BSG) for starch hydrolysis and bioethanol production was studied. BSG is a solid agro-industrial waste material produced from the brewing process. Member countries of the European Community generate millions of tons annually, but their utilization still remains limited. Aspergillus awamori was used for starch conversion and Saccharomyces cerevisiae for sugar conversion to bioethanol. HPLC and GC-FID analysis were performed for the determination of produced sugars and bioethanol, respectively. Pretreatments of BSG were examined for the enhancement of hydrolysis rate and bioethanol concentration. Finally, a co-immobilized co-culture A. awamori–S. cerevisiae was used for bioethanol production. This system reduces the required time and the equipment cost. Both microorganisms were immobilized on delignified BSG. Electron microscope spectroscopy was used for the observation of cells immobilization. High conversion rate of BSG starch to bioethanol was achieved by this biological, low-cost and environmentally friendly method that could be applied in the utilization of starchy agro-industrial wastes.
- Published
- 2011
- Full Text
- View/download PDF
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