17 research outputs found

    The evaluation of antioxidant activity of milling fractions of selected cereals grown in the year 2010

    Get PDF
    Cereals are good source of biologically active compounds that contribute to reducing the risk of coronary heart disease and also inhibit oxidation in human plasma. The aim of this study was to evaluate of antioxidant potential of four milling fractions of selected cereals grown in the year 2010. Methanol was used to extract the antioxidant compounds from cereals. Free radical scavenging activity of samples was measured using DPPH assay and reducing power was determined using FRAP assay. Secondary was evaluated of total phenolic and flavonoid content of cereal extracts. We found that flour fractions (break flour and reduction flour) showed the lower proportion of the total antioxidant potential than bran fractions (fine bran and coarse bran). Extract from barley had the highest values of antioxidant activity and phenolic content

    Old but still good – Comparison of malting and brewing characteristics of current and historical malting barley varieties

    Get PDF
    Historical Czech malting barley varieties Chlumecký, Stupický staročeský, Opavský Kneifel, and Diamant were tested in pilot malting and brewing tests (50 L) of 12% pale lager and compared with five Czech barley varieties recommended for the production of the beer with the protected geographical indication ‘České pivo’. The grain yield of the historical varieties (6.00–7.83 t/ha) was lower compared to the current varieties (8.23–9.39 t/ha). The malts from the historical varieties had high nitrogen content (12.45–13.89%), and low extract (75.2–78.6%, proteolytic (Kolbach index 37.4–40.9%) and cytolytic modification (friability 46.2–57.7%) was also low. Apart from lower extract yield and lower beer filtration rate, the experimental malts from the historical varieties were well processable in the pilot brewery. The sensory quality of the beers was very good (overall impression 3.3–3.8 points), fully comparable to beers made from malts from current barley varieties (3.4–3.9 points). Cluster analysis clearly differentiated the sensory profile of beers of historical and current barley varieties. The historical malting barley varieties under study may find their use mainly in the production of regional microbreweries

    Can biotechnology contribute to the development of research and innovation smart specialization strategy (RIS3) in Central and East European countries? Reminiscences from the European Workshop

    No full text
    The paper presents main results and recommendations of the recent European Workshop dedicated to the evaluation of current state and prospects for Biotechnology with the attention to Central and European countries. The contribution of Biotechnology to the RIS3 strategy is also briefly presented. It is believed that there is still insufficient integration of research and innovation, especially in Central and Eastern European countries. Another problem is the weak interest and lack of mechanisms for the entry of potential investors into biotechnology capital–intensive areas. Series of proposals and recommendations coming from the Workshop on how to increase the regional cooperation in the field of Biotechnology is briefly described together with the potential role of international institutions (JRC-EC, CEI, ICGEB, EBTNA) in such cooperation

    Effect Of Metal Ions On Triphenylmethane Dye Decolorization By Laccase From Trametes Versicolor

    No full text
    The aim of this study was investigate the influence of different metal ions on laccase activity and triphenylmethane dye decolorization by laccase from white-rot fungus Trametes versicolor. Laccase activity was inhibited by monovalent ions (Li+, Na+, K+ and Ag+) but the presence of divalent ions increased laccase activity at the concentration of 10 mmol/l. The effect of metal ions on decolorization of triphenylmethane dyes with different structures namely Bromochlorophenol Blue, Bromophenol Blue, Bromocresol Blue and Phenol Red was tested. The presence of metal ions (Na+, K+, Mg2+, Ca2+, Ba2+, Mn2+, Zn2+) slightly decreased triphenylmethane dye decolorization by laccase from T. versicolor except Na+ and Mg2+, which caused the increase of decolorization for all tested dyes. Decolorization of selected dyes showed that the presence of low-molecular-weight compounds is necessary for effective decolorization. Hydroxybenzotriazole (HBT) is the most frequently used. Although HBT belongs to most frequently used redox mediator and generally increase decolorization efficiency, so its presence decreased decolorization percentage of Bromophenol Blue and Bromochlorophenol Blue, the influence of metal ions to dye decolorization by laccase has the similar course with or without presence of redox mediator HBT

    Degradation of Synthetic Dyes by Laccases – A Mini-Review

    No full text
    Laccases provide a promising future as a tool to be used in the field of biodegradation of synthetic dyes with different chemical structures. These enzymes are able to oxidize a wide range of phenolic substrates without the presence of additional co-factors. Laccases have been confirmed for their potential of synthetic dye degradation from wastewater and degradation products of these enzymatic reactions become less toxic than selected dyes. This study discusses the potential of laccase enzymes as agents for laccase-catalyzed degradation in terms of biodegradation efficiency of synthetic dyes, specifically: azo dyes, triphenylmethane, indigo and anthraquinone dyes. Review also summarizes the laccase-catalyzed degradation mechanisms of the selected synthetic dyes, as well as the degradation products and the toxicity of the dyes and their degradation products

    Laccases as Effective Tools in the Removal of Pharmaceutical Products from Aquatic Systems

    No full text
    This review aims to provide a comprehensive overview of the application of bacterial and fungal laccases for the removal of pharmaceuticals from the environment. Laccases were evaluated for their efficacy in degrading pharmaceutical substances across various categories, including analgesics, antibiotics, antiepileptics, antirheumatic drugs, cytostatics, hormones, anxiolytics, and sympatholytics. The capability of laccases to degrade or biotransform these drugs was found to be dependent on their structural characteristics. The formation of di-, oligo- and polymers of the parent compound has been observed using the laccase mediator system (LMS), which is advantageous in terms of their removal via commonly used processes in wastewater treatment plants (WWTPs). Notably, certain pharmaceuticals such as tetracycline antibiotics or estrogen hormones exhibited degradation or even mineralization when subjected to laccase treatment. Employing enzyme pretreatment mitigated the toxic effects of degradation products compared to the parent drug. However, when utilizing the LMS, careful mediator selection is essential to prevent potential increases in environment toxicity. Laccases demonstrate efficiency in pharmaceutical removal within WWTPs, operating efficiently under WWTP conditions without necessitating isolation

    The optimization of propagation medium for the increase of laccase production by the white-rot fungus Pleurotus ostreatus

    No full text
    The lignocellulolytic enzymes are routinely produced by submerged fermentation using lignocellulosic material, but for more effective production, it would be suitable to precede the production phase on the lignocellulose by propagation phase in the nutrition medium suitable for growth of the fungi. Therefore, the aim of this study was to increase the laccase production by the white-rot fungus Pleurotus ostreatus by two-step cultivation strategy. In the first step, propagation medium was optimized for the maximal biomass growth, the second step included the laccase production by produced fungal biomass in media with the selected lignocellulosic material (pine sawdust, alfalfa steam and corn straw). From our experiments, parameters such as glucose concentration, yeast extract concentration and pH of propagation medium were selected as key factors affecting growth of P. ostreatus. The optimal conditions of propagation medium for maximal fungal growth determined by response surface methodology were: glucose concentration 102.68 g/L, yeast extract concentration 43.65 g/L and pH of propagation medium 7.24. These values were experimentally verified and used statistical model of biomass production prediction was appropriate adjusted. Thus prepared fungal biomass produced in the media with lignocellulose approximately 9-16 times higher concentrations of the laccase in 3 times shorter time than the fungal biomass without propagation phase in optimized propagation medium

    RESPONSE SURFACE METHODOLOGY FOR OPTIMIZATION OF THE EXTRACTION OF FLAX (LINUM USITATISSIMUM) SEED OIL

    No full text
    <table style="height: 310px;" border="0" cellspacing="0" cellpadding="0" width="664" align="left"><tbody><tr><td height="310" align="left" valign="top"><p>Flax seed is an important source of &omega;-3 polyunsaturated fatty acids essential for human physiology. The aim of this paper is to investigate the effects of major parameters of the lipid extraction from flax seed, in relation to the recovery of oil as well as the oil quality properties. The independent variables of extraction were proposed as: organic solvents, temperature, extraction time and solid-liquid ratio. The following quantitative and qualitative parameters were chosen as dependent variables: yield of the lipid fraction, acid value of oil and the absorbance at 490 nm. After calculating the optimal values of the extraction, the validation analysis was carried out and it was found out that the predicted and experimentally verified dependent variables were in agreement with the optimal extraction parameters.<br /><br /><strong>doi:10.5219/168</strong></p></td></tr></tbody></table

    Optimization of Propagation Medium for Enhanced Polyhydroxyalkanoate Production by <i>Pseudomonas oleovorans</i>

    No full text
    Polyhydroxyalkanoates (PHAs) represent a promising alternative to commercially used petroleum-based plastics. Pseudomonas oleovorans is a natural producer of medium-chain-length PHA (mcl-PHA) under cultivation conditions with nitrogen limitation and carbon excess. Two-step cultivation appears to be an efficient but more expensive method of PHA production. Therefore, the aim of this work was to prepare a minimal synthetic medium for maximum biomass yield and to optimize selected independent variables by response surface methodology (RSM). The highest biomass yield (1.71 ± 0.04 g/L) was achieved in the optimized medium containing 8.4 g/L glucose, 5.7 g/L sodium ammonium phosphate and 35.4 mM phosphate buffer. Under these conditions, both carbon and nitrogen sources were completely consumed after 48 h of the cultivation and the biomass yield was 1.7-fold higher than in the conventional medium recommended by the literature. This approach demonstrates the possibility of using two-stage PHA cultivation to obtain the maximum amount of biomass and PHA

    Optimization of Propagation Medium for Enhanced Polyhydroxyalkanoate Production by Pseudomonas oleovorans

    No full text
    Polyhydroxyalkanoates (PHAs) represent a promising alternative to commercially used petroleum-based plastics. Pseudomonas oleovorans is a natural producer of medium-chain-length PHA (mcl-PHA) under cultivation conditions with nitrogen limitation and carbon excess. Two-step cultivation appears to be an efficient but more expensive method of PHA production. Therefore, the aim of this work was to prepare a minimal synthetic medium for maximum biomass yield and to optimize selected independent variables by response surface methodology (RSM). The highest biomass yield (1.71 &plusmn; 0.04 g/L) was achieved in the optimized medium containing 8.4 g/L glucose, 5.7 g/L sodium ammonium phosphate and 35.4 mM phosphate buffer. Under these conditions, both carbon and nitrogen sources were completely consumed after 48 h of the cultivation and the biomass yield was 1.7-fold higher than in the conventional medium recommended by the literature. This approach demonstrates the possibility of using two-stage PHA cultivation to obtain the maximum amount of biomass and PHA
    corecore