A. Varga, Z. Bata, Pál Csuka, Diana Monica Bordea, B. Vértessy, A. Marcovici, F. Irimie, L. Poppe, L. Bencze
{"title":"A novel phenylalanine ammonia-lyase from Kangiella koreensis","authors":"A. Varga, Z. Bata, Pál Csuka, Diana Monica Bordea, B. Vértessy, A. Marcovici, F. Irimie, L. Poppe, L. Bencze","doi":"10.24193/SUBBCHEM.2017.3.25","DOIUrl":"https://doi.org/10.24193/SUBBCHEM.2017.3.25","url":null,"abstract":"This study describes the cloning of the gene encoding a novel phenylalanine ammonia-lyase from Kangiella koreensis (KkPAL) into pET19b expression vector. Optimization of protein expression and purification conditions yielded 15 mg pure soluble protein from one liter of E. coli culture. Enzymatic activity measurements of the ammonia elimination reaction from different natural aromatic amino acids proved the protein to be a phenylalanine ammonia-lyase. The isolated protein showed remarkably high, 81.7 °C melting temperature, making it especially suitable for biocatalytic applications.","PeriodicalId":22005,"journal":{"name":"Studia Universitatis Babes-bolyai Chemia","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89875203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Szabolcs Vígh, Z. Cziáky, L. Sinka, C. Pribac, L. Moș, V. Turcuș, J. Remenyik, E. Máthé
{"title":"Analysis of phytoconstituent profile of fenugreek –Trigonella Foenuem-graecum L. - seed extracts","authors":"Szabolcs Vígh, Z. Cziáky, L. Sinka, C. Pribac, L. Moș, V. Turcuș, J. Remenyik, E. Máthé","doi":"10.24193/SUBBCHEM.2017.2.11","DOIUrl":"https://doi.org/10.24193/SUBBCHEM.2017.2.11","url":null,"abstract":"Fenugreek (Trigonella foenum-graecum L.) is a well-known herb for its efficiency in the prevention/treatment of diabetes among other chronic diseases. The aim of present study was to analyse the phytoconstituent profile of aqueous and hydro-alcoholic extracts of fenugreek seeds produced in Hungary. The aqueous and hydro-aqueous extracts were analysed using a UHPLC-ESI-MS approach, and in the first 54, while in the second extract 67 phytoconstituents were identified that mostly corroborate the previously described health promoting effects of fenugreek. However, it remains a huge challenge to correlate the phytoconstituent composition of the two extracts with the generated dose dependent hormetic response and cytotoxic effects that were reported by us in case of some human breast cancerous cell lines.","PeriodicalId":22005,"journal":{"name":"Studia Universitatis Babes-bolyai Chemia","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77396541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
É. Molnár, Dóra Rippel-Pethő, G. Horváth, J. Bobek, R. Bocsi, Z. Hodai
{"title":"Removal of hydrogen sulphide content from biogas by atomizing of alkali solution","authors":"É. Molnár, Dóra Rippel-Pethő, G. Horváth, J. Bobek, R. Bocsi, Z. Hodai","doi":"10.24193/SUBBCHEM.2017.3.22","DOIUrl":"https://doi.org/10.24193/SUBBCHEM.2017.3.22","url":null,"abstract":"Our energy requirements increased significant in the last decades. For this reason the potential utilization of renewable energy sources come into view. Biogas is a kind of renewable energy sources. Purification of raw biogas is essential prior to use. Mainly the hydrogen sulfide content of gas is very harmful. It can cause corrosion in compressors and engines. Furthermore sulfur dioxide and sulfur trioxide are formed from hydrogen sulfide due to combustion, which similarly corrosive present of water and toxic like hydrogen sulfide. We examined the hydrogen sulfide absorption from biogas model gas mixtures (CO2, H2S, N2) based on alkali competitive chemisorption technology.","PeriodicalId":22005,"journal":{"name":"Studia Universitatis Babes-bolyai Chemia","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72522227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Carbon dioxide removal using ammonia in biogas upgrading and purification","authors":"Ireen Maile, E. Muzenda","doi":"10.24193/SUBBCHEM.2017.4.40","DOIUrl":"https://doi.org/10.24193/SUBBCHEM.2017.4.40","url":null,"abstract":"An alternative source of energy like biogas has become of interest to reduce the dependence on depleting fossil fuels for the source of energy. It is environmentally friendly and can be generated from various biomass wastes. It consists of CH4 (55%65%) and CO2 (35%45%) with a calorific value of 22 00025 000 kJ/m3 when raw and after CO2 is removed, the methane gas has a calorific value up to 39 000 kJ/ m3 and is referred to as biomethane. Ammonia is used as an absorbent in chemical scrubbing to remove CO2 from biogas. A continuous system consisting of 1L digester was used for biogas production which was bubbled through an absorbent in 500mL gas washing bottle at a constant temperature in a water bath. The obtained biomethane potential was found to be 0.387 m3 CH4/ kg VS which simply means that more methane gas can be obtained when using ammonia for absorption. An increase in the gas flow rate leads to an increase in the mass transfer coefficient resulting in an increase in the rate of absorption. The initial CO2 concentration affects the removal efficiency because more work needs to be done for biogas with a high initial concentration of CO2. NH3 has better absorption capacity because higher biogas purity was achieved at lower NH3 concentration. The removal efficiency for NH3 increased from 69%-79% on average with CH4 concentration reaching over 85% vol. This is equivalent to a calorific value ranging from 2533.5 MJ/Nm3 which is promising in terms of the gas ability to run in an automobile engine.","PeriodicalId":22005,"journal":{"name":"Studia Universitatis Babes-bolyai Chemia","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84773234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
É. Molnár, Dóra Rippel-Pethő, G. Horváth, J. Bobek, R. Bocsi, Z. Hodai
{"title":"Study of selective hydrogen sulfide absorption by comparing two different alkali absorbents by using atomization method","authors":"É. Molnár, Dóra Rippel-Pethő, G. Horváth, J. Bobek, R. Bocsi, Z. Hodai","doi":"10.24193/SUBBCHEM.2017.3.23","DOIUrl":"https://doi.org/10.24193/SUBBCHEM.2017.3.23","url":null,"abstract":"Significant part of the energy need of the world is covered by utilization of natural gas. Due to the hydrogen sulphide content of raw gas the natural gas industry has to tackle some serious problems, for example corrosion-, environmental-, economicand safety engineering problems. Our aim is to develop the selective hydrogen sulfide absorption by using alkali solutions. Experiments were performed in a specially designed atomizing reactor by using potassiumand sodium hydroxide absorbents. During the tests the following parameters have changed: contact time, pressure, volumetric flow rate of gas and liquid, concentration and material quality of absorbents. Three different model gas mixtures were used for measurements; they consist of nitrogen, carbon dioxide and hydrogen sulfide.","PeriodicalId":22005,"journal":{"name":"Studia Universitatis Babes-bolyai Chemia","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78753914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}