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Chengolova Z, Ivanov Y, Godjevargova T. Comparison of Identification and Quantification of Polyphenolic Compounds in Skins and Seeds of Four Grape Varieties. Molecules 2023; 28:molecules28104061. [PMID: 37241801 DOI: 10.3390/molecules28104061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/07/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
The aim of this study was to identify and quantify polyphenolic compounds in skin extracts from four Bulgarian grape varieties and compare them to those of seed extracts. The values of total phenolic contents, flavonoids, anthocyanins, procyanidins and an ascorbic acid in grape skin extracts were determined. The antioxidant capacities of skin extracts were evaluated using four different methods. The total phenolic content of skin extracts was 2-3 times lower than those of seed extracts. The significant difference between total parameter values of individual grape varieties were also found. According to the total phenolic content and antioxidant capacity of skin extracts, the different grape varieties were arranged in the following order: Marselan ≥ Pinot Noir ˃ Cabernet Sauvignon ˃ Tamyanka. The individual compounds in the grape skin extracts were determined using RP-HPLC and compared with those of the seed extracts. The determined composition of skin extracts was significantly different from the seed extracts' composition. Quantitative evaluation of the procyanidins and catechins in the skins was carried out. A correlation between phenolic contents, individual compounds and antioxidant capacity of different extracts was found. The studied grape extracts have a potential to be applied as natural antioxidants in the pharmaceutical and food industries.
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Affiliation(s)
- Zlatina Chengolova
- Department Biotechnology, University "Prof. Dr. A. Zlatarov", 8010 Burgas, Bulgaria
| | - Yavor Ivanov
- Department Biotechnology, University "Prof. Dr. A. Zlatarov", 8010 Burgas, Bulgaria
| | - Tzonka Godjevargova
- Department Biotechnology, University "Prof. Dr. A. Zlatarov", 8010 Burgas, Bulgaria
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2
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Krasteva D, Ivanov Y, Chengolova Z, Godjevargova T. Simultaneous enumeration of CD34 + and CD45 + cells using EasyCounter image cytometer. Anal Biochem 2021; 632:114351. [PMID: 34419455 DOI: 10.1016/j.ab.2021.114351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 08/11/2021] [Accepted: 08/17/2021] [Indexed: 10/20/2022]
Abstract
Accurate counting of CD34-positive cells is important for successful hematopoietic stem cell transplantation that is applied to various diseases. The aim of this study was simultaneous counting of viable CD34+ (vCD34+) and CD45+ (vCD45+) cells in apheresis samples by automatic immunofluorescence counter - EasyCounter BC. CD34+ and CD45+ cells were counted using two conjugates anti-CD34 antibody - dR110 and anti-CD45 antibody - ATTO620, respectively. The conjugates were prepared by carbodiimide method. Dead nuclear cells were counted by using monomethine cyanine dye PO-TEDM 1. The linearity and reproducibility of EasyCounter BC for CD34+ cell counting were determined (R2 = 0.99; CV values for vCD34+ cells were 6.8 ÷ 8.5% and for vCD45+ cells 4.1 ÷ 7.2%). The obtained results by EasyCounter BC were compared with those by other two standard methods - flow cytometry (Guava easyCyte 8HT) and fluorescence microscopic method (Olympus BX51) with the same conjugates. Passing-Bablok regression was performed to determine the relationship between the results of the three methods, analyzing 43 apheresis samples. Correlation coefficients for vCD45+ and vCD34+ between EasyCounter BC and Olympus microscope were 0.987 and 0.982, respectively (P < 0.0001). Better results were obtained between EasyCounter BC and flow cytometer Guava, 0.998 for vCD45+ and 0.998 for vCD34+ (P < 0.0001).
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Affiliation(s)
- Dimitrina Krasteva
- Department of Biotechnology, Prof. Dr. A. Zlatarov University, Burgas, Bulgaria
| | - Yavor Ivanov
- Department of Biotechnology, Prof. Dr. A. Zlatarov University, Burgas, Bulgaria
| | - Zlatina Chengolova
- Department of Biotechnology, Prof. Dr. A. Zlatarov University, Burgas, Bulgaria.
| | - Tzonka Godjevargova
- Department of Biotechnology, Prof. Dr. A. Zlatarov University, Burgas, Bulgaria
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Hendrickson OD, Zvereva EA, Zherdev AV, Godjevargova T, Xu C, Dzantiev BB. Development of a double immunochromatographic test system for simultaneous determination of lincomycin and tylosin antibiotics in foodstuffs. Food Chem 2020; 318:126510. [PMID: 32155562 DOI: 10.1016/j.foodchem.2020.126510] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 02/21/2020] [Accepted: 02/25/2020] [Indexed: 10/24/2022]
Abstract
This study is devoted to the development of a sensitive immunochromatographic analysis (ICA) for simultaneous determination of tylosin (TYL) and lincomycin (LIN) as antibiotics of the macrolide and lincosamide classes, widely used in animal husbandry and implicated in the contamination of foodstuffs. The ICA was implemented in an indirect competitive format, using antispecies antibodies conjugated with gold nanoparticles (GNPs) as a label. After the multistep optimization, the developed double ICA allowed for antibiotics detection with instrumental limits of detection/cutoff levels of 0.09/2 ng/mL and 0.008/0.8 ng/mL for TYL and LIN, respectively, within 10 min. The cross-reactivity was 40% to lincosamide clindamycin and negligible to other antibiotics tested. The test system allowed for the detection of TYL and LIN in milk, honey, and eggs. The recoveries of antibiotics from foodstuffs were 87.5-112.5%. The results demonstrate that the developed double ICA is an effective approach for the detection of other food contaminants.
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Affiliation(s)
- Olga D Hendrickson
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky prospect 33, Moscow 119071, Russia
| | - Elena A Zvereva
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky prospect 33, Moscow 119071, Russia
| | - Anatoly V Zherdev
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky prospect 33, Moscow 119071, Russia
| | | | - Chuanlai Xu
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Boris B Dzantiev
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky prospect 33, Moscow 119071, Russia.
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Godjevargova T, Becheva Z, Ivanov Y, Tchorbanov A. Immunofluorescence Assay Using Monoclonal and Polyclonal Antibodies for Detection of Staphylococcal Enterotoxins A in Milk. ACTA ACUST UNITED AC 2019. [DOI: 10.2174/187407070190130137] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Objectives:
Staphylococcus aureus is a Gram-positive microorganism. S. aureus can grow in various foods and cause food poisoning by secreting enterotoxins. The most common enterotoxins involved in food poisoning are staphylococcal enterotoxin A and staphylococcal enterotoxin B, but Staphylococcal Enterotoxin A (SEA) is predominant. The main types of food contaminated with SEs are meat and meat products, poultry and eggs, milk and dairy products. The aim of this study was to develop a rapid and sensitive fluorescence immunoassay for detection of staphylococcal enterotoxin A in milk.
Methods:
Monoclonal and polyclonal antibodies for SEA were produced and characterized. Competitive fluorescence immunoassay based on Magnetic Nanoparticles (MNPs) was performed and optimized. MNPs were used as a solid carrier of the antibodies. The first step of the assay was immunoreaction between the immobilized antibody onto MNPs and SEA in milk sample. Then the fluorescein-SEA conjugate was added to the sample. Thus, competitive immunoreaction between MNP-mAb/MNP-pAb with SEA and SEA-FITC was performed. These immuno-complexes were separated by a magnetic separator and the obtained supernatants were analyzed. The fluorescent signal from the excess of conjugated SEA was proportional to the SEA contained in the milk. The assay duration was only 30 min.
Results:
The fluorescence immunoassays performed with polyclonal antibody had linear ranges from 5 pg/mL to 100 ng/mL SEA in a buffer, and from 50 pg/mL to 50 ng/mL SEA in spiked milk samples. While the same assays performed with monoclonal antibody had linear ranges from 1 pg/mL to 20 ng/mL SEA in buffer, and from 10 pg/mL to 10 ng/mL SEA in spiked milk samples. The detection limits of the developed immunoassays performed in milk were: 48 pg/mL with polyclonal antibody and 9 pg/mL with monoclonal antibody.
Conclusion:
A rapid and sensitive fluorescence immunoassay based on magnetic nanoparticles with a polyclonal and monoclonal antibody for determination of staphylococcal enterotoxin A in milk was developed.
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Atanasova M, Yordanova G, Nenkova R, Ivanov Y, Godjevargova T, Dinev D. Brewing yeast viability measured using a novel fluorescent dye and image cytometer. BIOTECHNOL BIOTEC EQ 2019. [DOI: 10.1080/13102818.2019.1593053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- Milka Atanasova
- Department of Biotechnology, University ‘Prof. Dr. Assen Zlatarov’, Bourgas, Bulgaria
| | - Galina Yordanova
- Department of Biotechnology, University ‘Prof. Dr. Assen Zlatarov’, Bourgas, Bulgaria
| | - Ruska Nenkova
- Department of Biotechnology, University ‘Prof. Dr. Assen Zlatarov’, Bourgas, Bulgaria
| | - Yavor Ivanov
- Department of Biotechnology, University ‘Prof. Dr. Assen Zlatarov’, Bourgas, Bulgaria
| | - Tzonka Godjevargova
- Department of Biotechnology, University ‘Prof. Dr. Assen Zlatarov’, Bourgas, Bulgaria
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Becheva Z, Ivanov Y, Gabrovska K, Godjevargova T. Rapid immunofluorescence assay for staphylococcal enterotoxin A using magnetic nanoparticles. Int J Food Sci Technol 2018. [DOI: 10.1111/ijfs.14018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zlatina Becheva
- Department of Biotechnology University of “Prof. Dr Assen Zlatarov” 8010 Burgas Bulgaria
| | - Yavor Ivanov
- Department of Biotechnology University of “Prof. Dr Assen Zlatarov” 8010 Burgas Bulgaria
| | - Katya Gabrovska
- Department of Biotechnology University of “Prof. Dr Assen Zlatarov” 8010 Burgas Bulgaria
| | - Tzonka Godjevargova
- Department of Biotechnology University of “Prof. Dr Assen Zlatarov” 8010 Burgas Bulgaria
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Yaneva M, Ivanov Y, Todorov N, Godjevargova T. Magnetic-nanoparticles-based fluorescent immunoassay for individual and simultaneous determination of dichlorvos and paraoxon in milk. FOOD AGR IMMUNOL 2017. [DOI: 10.1080/09540105.2017.1368458] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
- Marina Yaneva
- Department of Biotechnology, University “Prof. Dr Asen Zlatarov”, Bourgas, Bulgaria
| | - Yavor Ivanov
- Department of Biotechnology, University “Prof. Dr Asen Zlatarov”, Bourgas, Bulgaria
| | - Nikola Todorov
- Department of Ecology, University “Prof. Dr Asen Zlatarov”, Bourgas, Bulgaria
| | - Tzonka Godjevargova
- Department of Biotechnology, University “Prof. Dr Asen Zlatarov”, Bourgas, Bulgaria
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Affiliation(s)
- Tsvetomira Ivanova
- Department of Biotechnology; University ‘Prof. Dr. A. Zlatarov’; Prof. Y. Yakimov Str. 1 8010 Bourgas Bulgaria
| | - Tzonka Godjevargova
- Department of Biotechnology; University ‘Prof. Dr. A. Zlatarov’; Prof. Y. Yakimov Str. 1 8010 Bourgas Bulgaria
| | - Nedyalka Dimova
- Department of Biotechnology; University ‘Prof. Dr. A. Zlatarov’; Prof. Y. Yakimov Str. 1 8010 Bourgas Bulgaria
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Affiliation(s)
- Zlatina Becheva
- Department of Biotechnology, University “Prof. Dr Asen Zlatarov”, Bourgas, Bulgaria
| | - Katya Gabrovska
- Department of Biotechnology, University “Prof. Dr Asen Zlatarov”, Bourgas, Bulgaria
| | - Tzonka Godjevargova
- Department of Biotechnology, University “Prof. Dr Asen Zlatarov”, Bourgas, Bulgaria
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Affiliation(s)
- Milka Atanasova
- Departmennt of Biotechnology, University “Prof. Dr. Assen Zlatarov”, Bourgas, Bulgaria
| | - Nastya Vasileva
- Department of Biotechnology, University of Ruse “Angel Kanchev”, Razgrad, Bulgaria
| | - Tzonka Godjevargova
- Departmennt of Biotechnology, University “Prof. Dr. Assen Zlatarov”, Bourgas, Bulgaria
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Vasileva N, Ivanov Y, Damyanova S, Kostova I, Godjevargova T. Hydrolysis of whey lactose by immobilized β-galactosidase in a bioreactor with a spirally wound membrane. Int J Biol Macromol 2016; 82:339-46. [DOI: 10.1016/j.ijbiomac.2015.11.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 11/08/2015] [Accepted: 11/10/2015] [Indexed: 11/26/2022]
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12
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Nenkova R, Wu J, Zhang Y, Godjevargova T. Evaluation of Immobilization Techniques for the Fabrication of Nanomaterial-Based Amperometric Glucose Biosensors. ANAL LETT 2014. [DOI: 10.1080/00032719.2014.979364] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Ivanova S, Gabrovska K, Godjevargova T. Fluorescent immunoassay for determination of penicillin and sulphonamide residues in milk using carboxylic magnetic nanoparticles. INT J DAIRY TECHNOL 2014. [DOI: 10.1111/1471-0307.12172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Svetla Ivanova
- Department of Biotechnology; University “Prof. Dr. Assen Zlatarov”; Prof. Y. Yakimov Str. 1 8010 Bourgas Bulgaria
| | - Katya Gabrovska
- Department of Biotechnology; University “Prof. Dr. Assen Zlatarov”; Prof. Y. Yakimov Str. 1 8010 Bourgas Bulgaria
| | - Tzonka Godjevargova
- Department of Biotechnology; University “Prof. Dr. Assen Zlatarov”; Prof. Y. Yakimov Str. 1 8010 Bourgas Bulgaria
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Yordanova G, Godjevargova T, Nenkova R, Ivanova D. Biodegradation of Phenol and Phenolic Derivatives by a Mixture of Immobilized Cells ofAspergillus AwamoriandTrichosporon Cutaneum. BIOTECHNOL BIOTEC EQ 2014. [DOI: 10.5504/bbeq.2013.0003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Ivanov Y, Marinov I, Portaccio M, Lepore M, Mita DG, Godjevargova T. Flow-Injection System with Site-Specific Immobilization of Acetylcholinesterase Biosensor for Amperometric Detection of Organophosphate Pesticides. BIOTECHNOL BIOTEC EQ 2014. [DOI: 10.5504/bbeq.2012.0033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Nenkova R, Wu J, Zhang Y, Godjevargova T. Influence of different nanozeolite particles on the sensitivity of a glucose biosensor. Anal Biochem 2013; 439:65-72. [DOI: 10.1016/j.ab.2013.04.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 04/03/2013] [Accepted: 04/04/2013] [Indexed: 10/27/2022]
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Ramesh R, Aarthy M, Gowthaman MK, Gabrovska K, Godjevargova T, Kamini NR. Screening and production of a potent extracellularArthrobacter creatinolyticusurease for determination of heavy metal ions. J Basic Microbiol 2013; 54:285-95. [DOI: 10.1002/jobm.201200561] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 11/18/2012] [Indexed: 11/11/2022]
Affiliation(s)
- Rajendran Ramesh
- Department of Biotechnology; Central Leather Research Institute; Adyar, Chennai, Tamil Nadu India
| | - Mayilvahanan Aarthy
- Department of Biotechnology; Central Leather Research Institute; Adyar, Chennai, Tamil Nadu India
| | | | - Katya Gabrovska
- Department of Biotechnology; University “Prof. Dr. A. Zlatarov,”; Bourgas Bulgaria
| | - Tzonka Godjevargova
- Department of Biotechnology; University “Prof. Dr. A. Zlatarov,”; Bourgas Bulgaria
| | - Numbi Ramudu Kamini
- Department of Biotechnology; Central Leather Research Institute; Adyar, Chennai, Tamil Nadu India
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Ivanova S, Ivanov Y, Godjevargova T. Urea Amperometric Biosensors Based on Nanostructured Polypyrrole and Poly Ortho-Phenylenediamine. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ojab.2013.21002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Georgieva S, Godjevargova T, Mita D, Diano N, Menale C, Nicolucci C, Carratelli CR, Mita L, Golovinsky E. Non-isothermal bioremediation of waters polluted by phenol and some of its derivatives by laccase covalently immobilized on polypropylene membranes. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.molcatb.2010.05.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Ivanov Y, Marinov I, Gabrovska K, Dimcheva N, Godjevargova T. Amperometric biosensor based on a site-specific immobilization of acetylcholinesterase via affinity bonds on a nanostructured polymer membrane with integrated multiwall carbon nanotubes. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.molcatb.2010.01.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Stoilova O, Manolova N, Gabrovska K, Marinov I, Godjevargova T, Mita DG, Rashkov I. Electrospun Polyacrylonitrile Nanofibrous Membranes Tailored for Acetylcholinesterase Immobilization. J BIOACT COMPAT POL 2010. [DOI: 10.1177/0883911509353680] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Nanofibrous polyacrylonitrile membranes (PANNFM) were obtained by electrospinning and then prepared for immobilizing acetylcholinesterase (AChE). Initially, the chemical modification of PANNFM with ethylenediamine produced reactive groups to overcome their inertness and hydrophobicity. The natural polymer, chitosan, was then tethered on the nanofibrous membranes to improve their biocompatibility. Scanning electron microscopy (SEM) and cross-section SEM were used to determine morphological and porosity changes of the membranes. The immobilized AChE had greater relative activity as well as thermal and storage stability compared to the free enzyme. The bound AChE showed excellent reusability. Chitosan-modified PANNFM was shown to be a suitable strategy for facile immobilization of AChE to produce a promising system that effectively supports biocatalysts.
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Affiliation(s)
- Olya Stoilova
- Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev str., 103A, BG-1113 Sofia, Bulgaria
| | - Nevena Manolova
- Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev str., 103A, BG-1113 Sofia, Bulgaria,
| | - Katya Gabrovska
- University "Prof. Dr. Asen Zlatarov", Department of Biotechnology Prof Y. Yakimov str., 1, BG-8010 Burgas, Bulgaria
| | - Ivaylo Marinov
- University "Prof. Dr. Asen Zlatarov", Department of Biotechnology Prof Y. Yakimov str., 1, BG-8010 Burgas, Bulgaria
| | - Tzonka Godjevargova
- University "Prof. Dr. Asen Zlatarov", Department of Biotechnology Prof Y. Yakimov str., 1, BG-8010 Burgas, Bulgaria
| | - Damiano Gustavo Mita
- Laboratory of Biophysics, Institute of Genetics and Biophysics - CNR Pietro Castellino str., 111, 80131 Naples, Italy, National Institute of Biosystems and Biostructures (INBB) Via le Medaglie d'Oro, 305, 00136 Rome, Italy
| | - Iliya Rashkov
- Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev str., 103A, BG-1113 Sofia, Bulgaria
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Gabrovska K, Godjevargova T. Optimum immobilization of urease on modified acrylonitrile copolymer membranes: Inactivation by heavy metal ions. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.molcatb.2009.03.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Mita DG, Diano N, Grano V, Portaccio M, Rossi S, Bencivenga U, Manco I, Nicolucci C, Bianco M, Grimaldi T, Mita L, Georgieva S, Godjevargova T. The process of thermodialysis in bioremediation of waters polluted by endocrine disruptors. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.molcatb.2008.12.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Marinov I, Gabrovska K, Velichkova J, Godjevargova T. Immobilization of acetylcholinesterase on nanostructure polyacrylonitrile membranes. Int J Biol Macromol 2009; 44:338-45. [DOI: 10.1016/j.ijbiomac.2009.01.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 01/29/2009] [Accepted: 01/29/2009] [Indexed: 10/21/2022]
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Yordanova G, Ivanova D, Godjevargova T, Krastanov A. Biodegradation of phenol by immobilized Aspergillus awamori NRRL 3112 on modified polyacrylonitrile membrane. Biodegradation 2009; 20:717-26. [PMID: 19340590 DOI: 10.1007/s10532-009-9259-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Accepted: 03/18/2009] [Indexed: 11/30/2022]
Abstract
Covalent immobilization of Aspergillus awamori NRRL 3112 was conducted onto modified polyacrylonitrile membrane with glutaraldehyde as a coupling agent. The polymer carrier was preliminarily modified in an aqueous solution of NaOH and 1,2-diaminoethane. The content of amino groups was determined to be 0.58 mgeq g(-1). Two ways of immobilization were used-in the presence of 0.2 g l(-1) phenol and without phenol. The capability of two immobilized system to degrade phenol (concentration-0.5 g l(-1)) as a sole carbon and energy source was investigated in batch experiments. Seven cycles of phenol biodegradation were conducted. Better results were obtained with the immobilized system prepared in the presence of phenol, regarding degradation time and phenol biodegradation rate. Scanning electron micrographs of the polyacrylonitrile membrane/immobilized Aspergillus awamori NRRL at the beginning of repeated batch cultivation and after the 7th cycle were compared. After the 7th cycle of cultivation the observations showed large groups of cells. The results from the batch experiments with immobilized system were compared to the results produced by the free strain. Phenol biodegradation experiments were carried out also in a bioreactor with spirally wound membrane with bound Aspergillus awamori NRRL 3112 in a regime of recirculation. 10 cycles of 0.5 g l(-1) phenol biodegradation were run consecutively to determine the degradation time and rate for each cycle. The design of the bioreactor appeared to be quite effective, providing large membrane surface to bind the strain.
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Affiliation(s)
- G Yordanova
- Department of Biotechnology, University Prof. Dr. A Zlatarov, 1 Prof. Yakimov Str., 8010, Bourgas, Bulgaria
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Diano N, Grimaldi T, Bianco M, Rossi S, Gabrovska K, Yordanova G, Godjevargova T, Grano V, Nicolucci C, Mita L, Bencivenga U, Canciglia P, Mita DG. Apple juice clarification by immobilized pectolytic enzymes in packed or fluidized bed reactors. J Agric Food Chem 2008; 56:11471-11477. [PMID: 18986151 DOI: 10.1021/jf8019437] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The catalytic behavior of a mixture of pectic enzymes, covalently immobilized on different supports (glass microspheres, nylon 6/6 pellets, and PAN beads), was analyzed with a pectin aqueous solution that simulates apple juice. The following parameters were investigated: the rate constant at which pectin hydrolysis is conducted, the time (tau(50)) in which the reduction of 50% of the initial viscosity is reached, and the time (tau(comp,dep)) required to obtain complete depectinization. The best catalytic system was proven to be PAN beads, and their pH and temperature behavior were determined. The yields of two bed reactors, packed or fluidized, using the catalytic PAN beads, were compared to the circulation flow rate of real apple juice. The experimental conditions were as follows: pH 4.0, T = 50 degrees C, and beads volume = 20 cm(3). The initial pectin concentration was the one that was present in our apple juice sample. No differences were observed at low circulation rates, while at higher recirculation rates, the time required to obtain complete pectin hydrolysis into the fluidized reactor was found to be 0.25 times smaller than in the packed bed reactor: 131 min for the packed reactors and 41 min for the fluidized reactors.
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Affiliation(s)
- Nadia Diano
- Department of Experimental Medicine, Second University of Naples, Italy
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Gabrovska K, Marinov I, Godjevargova T, Portaccio M, Lepore M, Grano V, Diano N, Mita DG. The influence of the support nature on the kinetics parameters, inhibition constants and reactivation of immobilized acetylcholinesterase. Int J Biol Macromol 2008; 43:339-45. [DOI: 10.1016/j.ijbiomac.2008.07.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 07/02/2008] [Accepted: 07/03/2008] [Indexed: 11/30/2022]
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Georgieva S, Godjevargova T, Portaccio M, Lepore M, Mita D. Advantages in using non-isothermal bioreactors in bioremediation of water polluted by phenol by means of immobilized laccase from Rhus vernicifera. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.molcatb.2008.03.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Gabrovska K, Nedelcheva T, Godjevargova T, Stoilova O, Manolova N, Rashkov I. Immobilization of acetylcholinesterase on new modified acrylonitrile copolymer membranes. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.molcatb.2008.03.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Gabrovska K, Georgieva A, Godjevargova T, Stoilova O, Manolova N. Poly(acrylonitrile)chitosan composite membranes for urease immobilization. J Biotechnol 2007; 129:674-80. [PMID: 17320233 DOI: 10.1016/j.jbiotec.2007.01.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2006] [Revised: 01/16/2007] [Accepted: 01/18/2007] [Indexed: 11/21/2022]
Abstract
(Poly)acrylonitrile/chitosan (PANCHI) composite membranes were prepared. The chitosan layer was deposited on the surface as well as on the pore walls of the base membrane. This resulted in the reduction of the pore size of the membrane and in an increase of their hydrophilicity. The pore structure of PAN and PANCHI membranes were determined by TEM and SEM analyses. It was found that the average size of the pore under a selective layer base PAN membrane is 7 microm, while the membrane coated with 0.25% chitosan shows a reduced pore size--small or equal to 5 microm and with 0.35% chitosan--about 4 microm. The amounts of the functional groups, the degree of hydrophilicity and transport characteristics of PAN/Chitosan composite membranes were determined. Urease was covalently immobilized onto all kinds of PAN/chitosan composite membranes using glutaraldehyde. Both the amount of bound protein and relative activity of immobilized urease were measured. The highest activity (94%) was measured for urease bound to PANCHI2 membranes (0.25% chitosan). The basic characteristics (pH(opt), pH(stability), T(opt), T(stability), heat inactivation and storage stability) of immobilized urease were determined. The obtained results show that the poly(acrylonitrile)chitosan composite membranes are suitable for enzyme immobilization.
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Affiliation(s)
- Katya Gabrovska
- University Prof Dr A Zlatarov, Department of Biotechnology, Bourgas, Bulgaria
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Godjevargova T, Ivanova D, Aleksieva Z, Burdelova G. Biodegradation of phenol by immobilized Trichosporon cutaneum R57 on modified polymer membranes. Process Biochem 2006. [DOI: 10.1016/j.procbio.2006.05.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Turmanova S, Godjevargova T, Vasileva N. Immobilization of urease on cation-exchange membranes prepared by radiation-initiated graft copolymerization of acrylic acid on polyethene thin films. Polym Bull (Berl) 2005. [DOI: 10.1007/s00289-005-0456-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Godjevargova T, Nenkova R, Dimova N. Covalent Immobilization of Glucose Oxidase onto New Modified Acrylonitrile Copolymer/Silica Gel Hybrid Supports. Macromol Biosci 2005; 5:760-6. [PMID: 16080168 DOI: 10.1002/mabi.200400225] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
New polymer/silica gel hybrid supports were prepared by coating high surface area of silica gel with modified acrylonitrile copolymer. The concentrations of the modifying agent (NaOH) and the modified polymer were varied. GOD was covalently immobilized on these hybrid supports and the relative activity and the amount of bound protein were determined. The highest relative activity and sufficient amount of bound protein of the immobilized GOD were achieved in 10% NaOH and 2% solution of modified acrylonitrile copolymer. The influence of glutaraldehyde concentration and the storage time on enzyme efficiency were examined. Glutaraldehyde concentration of 0.5% is optimal for the immobilized GOD. It was shown that the covalently bound enzyme (using 0.5% glutaraldehyde) had higher relative activity than the activity of the adsorbed enzyme. Covalently immobilized GOD with 0.5% glutaraldehyde was more stable for four months in comparison with the one immobilized on pure silica gel, hybrid support with 10% glutaraldehyde and the free enzyme. The effect of the pore size on the enzyme efficiency was studied on four types of silica gel with different pore size. Silica with large pores (CPC-Silica carrier, 375 A) presented higher relative activity than those with smaller pore size (Silica gel with 4, 40 and 100 A). The amount of bound protein was also reduced with decreasing the pore size. The effect of particle size was studied and it was found out that the smaller the particle size was, the greater the activity and the amount of immobilized enzyme were. The obtained results proved that these new polymer/silica gel hybrid supports were suitable for GOD immobilization.
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Affiliation(s)
- Tzonka Godjevargova
- Department of Biotechnology, University Prof. Dr. Assen Zlatarov, Prof. Yakimov Street 1, Bourgas 8010, Bulgaria.
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Godjevargova T, Gabrovska K. Kinetic Parameters of Urease Immobilized on Modified Acrylonitrile Copolymer Membranes in the Presence and Absence of Cu(II) Ions. Macromol Biosci 2005; 5:459-66. [PMID: 15895477 DOI: 10.1002/mabi.200400188] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Poly(acrylonitrile-methylmethacrylate-sodium vinylsulfonate) membranes were subjected to seven different chemical modifications and the amount of the newly formed groups was measured for each membrane. Urease was then covalently immobilized onto the modified membranes and the amount of bound protein was determined. The kinetic parameters V(max) and K(m) of the immobilized urease were studied under static and dynamic conditions. Results showed that the rate of the enzyme reaction was higher for the membranes modified with NH(2)OH . H(2)SO(4), NH(2)NH(2) . H(2)SO(4), NaOH + EDA and NaOH + GA + EDA. It was confirmed that the reaction rate, measured under dynamic conditions, was higher than that one determined under static conditions. The influence of Cu(II) ions, as inhibitors, on the enzyme reaction kinetics (V(i) and K(i)) was also investigated. It turned out that the most sensitive membranes towards Cu(II) were those modified with NH(2)NH(2) . H(2)SO(4), NaOH + EDA and H(2)O(2). The results initiated further investigations on the influence of other heavy metal ions (Cd(II), Zn(II), Ni(II) and Pb(II)) over urease bound to a NH(2)OH . H(2)SO(4)-modified membrane. It was found that the inhibition effect of the heavy metal ions over immobilized urease decreases in the order: Cu(II) > Cd(II) > Zn(II) > Ni(II) > Pb(II). [Diagram: see text]
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Affiliation(s)
- Tzonka Godjevargova
- University Prof. Dr. A. Zlatarov, Department of Biotechnology, Prof. Y. Yakimov Str. 1, 8010 Bourgas, Bulgaria.
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Dayal R, Godjevargova T. Polyacrylonitrile Enzyme Ultrafiltration and Polyamide Enzyme Microfiltration Membranes Prepared by Diffusion and Convection. Macromol Biosci 2005; 5:222-8. [PMID: 15768441 DOI: 10.1002/mabi.200400132] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Glucose oxidase (GOD) and catalase (CAT) were covalently immobilized onto three types of polyacrylonitrile (PAN 1, PAN 2, and PAN 3) ultrafiltration (UF) membranes with different pore sizes and one type of polyamide (PA) microfiltration (MF) membrane by the bifunctional reagent, glutaraldehyde. The initial membranes were pre-modified to generate active amide groups in the PAN membranes and active amino groups in the PA membranes. The PAN 3 membrane contained the highest amount of active groups, and the membrane PA the lowest. The modified membranes were enzyme-loaded by diffusion and convection (UF). The effect of membrane pore size and immobilization methods on enzymatic activity and bound protein were studied. The most effective immobilized system was prepared by diffusion using a PAN 3 membrane as a carrier (bound protein: 0.055 mg/cm(2), relative activity: 87.6%). This membrane had the highest pore size of all the PAN membranes. Despite the highest pore size of PA membrane, the enzyme PA membranes prepared by diffusion showed the lowest amount of bound protein (0.03 mg/cm(2)) and the lowest relative activity (35.38%). This correlates with the lowest amount of active groups found in these membranes. The relative activity was higher for all the enzyme systems loaded by diffusion. The systems prepared by convection of the enzyme solution contained higher amounts of enzymes (0.035-0.13 mg/cm(2) protein), which led to internal substrate diffusion resistance and a decrease in the GOD relative activity (21.55-68.5%) in these systems. The kinetic parameters (V(max) and K(m)) and the glucose conversion of the immobilized systems prepared by diffusion were also studied. [diagram in text].
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Affiliation(s)
- Rajeshwar Dayal
- Department of Biotechnology, University, "Prof. Dr. Assen Zlatarov", Prof. Yakimov Street 1, Bourgas 8010, Bulgaria
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Godjevargova T, Dayal R, Turmanova S. Gluconic Acid Production in Bioreactor with Immobilized Glucose Oxidase Plus Catalase on Polymer Membrane Adjacent to Anion-Exchange Membrane. Macromol Biosci 2004; 4:950-6. [PMID: 15497133 DOI: 10.1002/mabi.200400058] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Gluconic acid was obtained in the permeate side of the bioreactor with glucose oxidase (GOD) immobilized onto anion-exchange membrane (AEM) of low-density polyethylene grafted with 4-vinylpiridine. The electric resistance of the anion-exchange membranes was increased after the enzyme immobilization on the membrane. The gluconic acid productions were relatively low with the GOD immobilized by any method on the AEM. To increase the enzyme reaction efficiency, GOD was immobilized on membrane of AN copolymer (PAN) adjacent to an anion-exchange membrane in bioreactor. Uses of anion-exchange membrane led to selective removal of the gluconic acid from the glucose solution and reduce the gluconic acid inhibition. The amount of gluconic acid obtained in the permeate side of the bioreactor with the GOD immobilized on the PAN membrane adjacent to the AEM under electrodialysis was about 30 times higher than that obtained with enzyme directly bound to the AEM. The optimal substrate concentration in the feed side was found to be about 1 g/l. Further experiments were carried out with the co-immobilized GOD plus Catalase (CAT) on the PAN membrane adjacent to the AEM to improve the efficiency of the immobilize system. The yield of this process was at least 95%. The storage stability of the co-immobilized GOD and CAT was studied (lost 20% of initial activity for 90 d). The results obtained clearly showed the higher potential of the dual membrane bioreactor with GOD plus CAT bound to ultrafiltration polymer membrane adjacent to the AEM. Storage stability of GOD activity in GOD plus CAT immobilized on PAN//AEM membranes and on AEM.
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Affiliation(s)
- Tzonka Godjevargova
- Department of Biotechnology, University, Prof. Dr. Assen Zlatarov Prof. Yakimov Street 1, Bourgas 8010, Bulgaria.
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Godjevargova T, Dayal R, Marinov I. Simultaneous covalent immobilization of glucose oxidase and catalase onto chemically modified acrylonitrile copolymer membranes. J Appl Polym Sci 2004. [DOI: 10.1002/app.13617] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Godjevargova T, Mihova S, Gabrovska K. Fixed-bed biosorption of Cu2+by polyacrylonitrile-immobilized dead cells of Saccharomyces cerevisiae. World J Microbiol Biotechnol 2004. [DOI: 10.1023/b:wibi.0000023831.41690.0c] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Godjevargova T, Vasileva N, Letskovska Z. Study of the thermal stability of glucose oxidase in the presence of water-soluble polymers. J Appl Polym Sci 2003. [DOI: 10.1002/app.12845] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
Poly (acrylonitrile-methylmethacrylate-sodium vinylsulfonate) membranes were subjected to seven different chemical modifications. The amounts of new groups incorporated in the membranes with the modifications were determined. Urease was covalently immobilized on the modified membranes. Both the amount of bound protein and relative activity of immobilized urease were measured. The highest activity was found for urease bound to membranes modified with hydroxylammonium sulfate (68%) and hydrazinium sulfate (67%). Optimum pH of free urease was determined to be 5.8. For positively charged membranes, pH optimum was shifted to higher values, while for negatively charged membranes-to lower pH. The charge of the matrix affected also the rate of the enzyme reaction. The highest rate was measured with urease immobilized on membranes modified with hydroxylammonium sulfate and hydrazinium sulfate. The major part of the immobilized enzyme on different modified membranes remained stable-only ca. 20% of enzyme activity was lost for 4 h at 70 degrees C while the free enzyme was totally inactivated.
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Affiliation(s)
- T Godjevargova
- Department of Biotechnology, University Professor Dr A. Zlatarov, Professor Y. Yakimov Str. 1, 8010 Bourgas, Bulgaria.
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Godjevargova T, Ivanova D, Alexieva Z, Dimova N. Biodegradation of toxic organic components from industrial phenol production waste waters by free and immobilized Trichosporon cutaneum R57. Process Biochem 2003. [DOI: 10.1016/s0032-9592(02)00170-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Godjevargova T, Simeonova A, Dimov A. Adsorption of heavy metal ions from aqueous solutions by porous polyacrylonitrile beads. J Appl Polym Sci 2002. [DOI: 10.1002/app.2334] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Godjevargova T, Aleksieva Z, Ivanova D. Cell immobilization of Trichosporon cutaneum strain with phenol degradation ability on new modified polymer carriers. Process Biochem 2000. [DOI: 10.1016/s0032-9592(99)00131-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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