The Experts below are selected from a list of 1416 Experts worldwide ranked by ideXlab platform
Claudia Gallert - One of the best experts on this subject based on the ideXlab platform.
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1Institute of Biology for Engineers and Biotechnology of Wastewater,
2016Co-Authors: Claudia GallertAbstract:Transformation of the matrix structure of shrimp shells during bacterial Deproteination and the protein and Ca matrix within the shrimp shell cuticle which might be helpful in developing shrimp wast
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Pilot-scale chitin extraction from shrimp shell waste by Deproteination and decalcification with bacterial enrichment cultures.
Applied microbiology and biotechnology, 2015Co-Authors: Mini Bajaj, Josef Winter, Andrea Freiberg, Claudia GallertAbstract:Extraction of chitin from mechanically pre-purified shrimp shells can be achieved by successive NaOH/HCl treatment, protease/HCl treatment or by environmentally friendly fermentation with proteolytic/lactic acid bacteria (LAB). For the last mentioned alternative, scale-up of shrimp shell chitin purification was investigated in 0.25 L (F1), 10 L (F2), and 300 L (F3) fermenters using an anaerobic, chitinase-deficient, proteolytic enrichment culture from ground meat for Deproteination and a mixed culture of LAB from bio-yoghurt for decalcification. Protein removal in F1, F2, and F3 proceeded in parallel within 40 h at an efficiency of 89-91 %. Between 85 and 90 % of the calcit was removed from the shells by LAB in another 40 h in F1, F2, and F3. After Deproteination of shrimp shells in F3, spent fermentation liquor was re-used for a next batch of 30-kg shrimp shells in F4 (300 L) which eliminated 85.5 % protein. The purity of the resulting chitin was comparable in F1, F2, F3, and F4. Viscosities of chitosan, obtained after chitin deacetylation and of chitin, prepared biologically or chemically in the laboratory, were much higher than those of commercially available chitin and chitosan.
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Transformation of the matrix structure of shrimp shells during bacterial Deproteination and demineralization
Microbial cell factories, 2013Co-Authors: Mini Bajaj, Josef Winter, Reinhard Schneider, Stephan L. Grage, Anne S. Ulrich, Claudia GallertAbstract:After cellulose and starch, chitin is the third-most abundant biopolymer on earth. Chitin or its deacetylated derivative chitosan is a valuable product with a number of applications. It is one of the main components of shrimp shells, a waste product of the fish industry. To obtain chitin from Penaeus monodon, wet and dried shrimp shells were deproteinated with two specifically enriched proteolytic cultures M1 and M2 and decalcified by in-situ lactic acid forming microorganisms. The viscosity of biologically processed chitin was compared with chemically processed chitin. The former was further investigated for purity, structure and elemental composition by several microscopic techniques and 13C solid state NMR spectroscopy. About 95% of the protein of wet shrimp shells was removed by proteolytic enrichment culture M2 in 68 h. Subsequent decalcification by lactic acid bacteria (LAB) took 48 h. Deproteination of the same amount of dried shrimps that contained a 3 × higher solid content by the same culture was a little bit faster and was finished after 140 h. The viscosity of chitin was in the order of chemically processed chitin > bioprocessed chitin > commercially available chitin. Results revealed changes in fine structure and chemical composition of the epi-, exo- and endocuticle of chitin from shrimp shells during microbial Deproteination and demineralization. From transmission electron microscopy (TEM) overlays and electron energy loss spectroscopy (EELS) analysis, it was found that most protein was present in the exocuticle, whereas most chitin was present in the endocuticle. The calcium content was higher in the endocuticle than in the exocuticle.13C solid state NMR spectra of different chitin confirmed
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effect of Deproteination and deacetylation conditions on viscosity of chitin and chitosan extracted from crangon crangon shrimp waste
Biochemical Engineering Journal, 2011Co-Authors: Mini Bajaj, Josef Winter, Claudia GallertAbstract:Abstract Deproteination of decalcified chitin from Crangon crangon shells and deacetylation to chitosan was investigated to find out optimum conditions for a high viscosity chitosan. Deproteination was carried out with an optimum shrimp shell:alkali (s:a) ratio of 1:4 from 30 °C to 65 °C and at each temperature, incubation times were varied from 2 to 5 h for maximal efficiency. Viscosity of the chemically extracted chitin samples at different temperature–time conditions ranged from 195 to 391 mPa s. A two-way ANOVA with Bonferroni post test was performed on experimental data. Chitin extracted at various temperatures and incubation times was deacetylated with 50% (w/w) NaOH at increasing reaction times. The highest chitosan viscosity of 1976 mPa s was observed in a sample deproteinated for 5 h at 55 °C and deacetylated for 1 h at 105 °C and 2 bar N 2 pressure. One-way ANOVA test for chitosan viscosity measurements indicated a significant P value of
Mini Bajaj - One of the best experts on this subject based on the ideXlab platform.
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Pilot-scale chitin extraction from shrimp shell waste by Deproteination and decalcification with bacterial enrichment cultures.
Applied microbiology and biotechnology, 2015Co-Authors: Mini Bajaj, Josef Winter, Andrea Freiberg, Claudia GallertAbstract:Extraction of chitin from mechanically pre-purified shrimp shells can be achieved by successive NaOH/HCl treatment, protease/HCl treatment or by environmentally friendly fermentation with proteolytic/lactic acid bacteria (LAB). For the last mentioned alternative, scale-up of shrimp shell chitin purification was investigated in 0.25 L (F1), 10 L (F2), and 300 L (F3) fermenters using an anaerobic, chitinase-deficient, proteolytic enrichment culture from ground meat for Deproteination and a mixed culture of LAB from bio-yoghurt for decalcification. Protein removal in F1, F2, and F3 proceeded in parallel within 40 h at an efficiency of 89-91 %. Between 85 and 90 % of the calcit was removed from the shells by LAB in another 40 h in F1, F2, and F3. After Deproteination of shrimp shells in F3, spent fermentation liquor was re-used for a next batch of 30-kg shrimp shells in F4 (300 L) which eliminated 85.5 % protein. The purity of the resulting chitin was comparable in F1, F2, F3, and F4. Viscosities of chitosan, obtained after chitin deacetylation and of chitin, prepared biologically or chemically in the laboratory, were much higher than those of commercially available chitin and chitosan.
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Transformation of the matrix structure of shrimp shells during bacterial Deproteination and demineralization
Microbial cell factories, 2013Co-Authors: Mini Bajaj, Josef Winter, Reinhard Schneider, Stephan L. Grage, Anne S. Ulrich, Claudia GallertAbstract:After cellulose and starch, chitin is the third-most abundant biopolymer on earth. Chitin or its deacetylated derivative chitosan is a valuable product with a number of applications. It is one of the main components of shrimp shells, a waste product of the fish industry. To obtain chitin from Penaeus monodon, wet and dried shrimp shells were deproteinated with two specifically enriched proteolytic cultures M1 and M2 and decalcified by in-situ lactic acid forming microorganisms. The viscosity of biologically processed chitin was compared with chemically processed chitin. The former was further investigated for purity, structure and elemental composition by several microscopic techniques and 13C solid state NMR spectroscopy. About 95% of the protein of wet shrimp shells was removed by proteolytic enrichment culture M2 in 68 h. Subsequent decalcification by lactic acid bacteria (LAB) took 48 h. Deproteination of the same amount of dried shrimps that contained a 3 × higher solid content by the same culture was a little bit faster and was finished after 140 h. The viscosity of chitin was in the order of chemically processed chitin > bioprocessed chitin > commercially available chitin. Results revealed changes in fine structure and chemical composition of the epi-, exo- and endocuticle of chitin from shrimp shells during microbial Deproteination and demineralization. From transmission electron microscopy (TEM) overlays and electron energy loss spectroscopy (EELS) analysis, it was found that most protein was present in the exocuticle, whereas most chitin was present in the endocuticle. The calcium content was higher in the endocuticle than in the exocuticle.13C solid state NMR spectra of different chitin confirmed
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effect of Deproteination and deacetylation conditions on viscosity of chitin and chitosan extracted from crangon crangon shrimp waste
Biochemical Engineering Journal, 2011Co-Authors: Mini Bajaj, Josef Winter, Claudia GallertAbstract:Abstract Deproteination of decalcified chitin from Crangon crangon shells and deacetylation to chitosan was investigated to find out optimum conditions for a high viscosity chitosan. Deproteination was carried out with an optimum shrimp shell:alkali (s:a) ratio of 1:4 from 30 °C to 65 °C and at each temperature, incubation times were varied from 2 to 5 h for maximal efficiency. Viscosity of the chemically extracted chitin samples at different temperature–time conditions ranged from 195 to 391 mPa s. A two-way ANOVA with Bonferroni post test was performed on experimental data. Chitin extracted at various temperatures and incubation times was deacetylated with 50% (w/w) NaOH at increasing reaction times. The highest chitosan viscosity of 1976 mPa s was observed in a sample deproteinated for 5 h at 55 °C and deacetylated for 1 h at 105 °C and 2 bar N 2 pressure. One-way ANOVA test for chitosan viscosity measurements indicated a significant P value of
Libor Vítek - One of the best experts on this subject based on the ideXlab platform.
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Comparison of simple extraction procedures in liquid chromatography-mass spectrometry based determination of serum 7α-hydroxy-4-cholesten-3-one, a surrogate marker of bile acid synthesis.
Journal of chromatography. B Analytical technologies in the biomedical and life sciences, 2016Co-Authors: Martin LeníĿek, Marek Vecka, Kateſina Žížalová, Libor VítekAbstract:The serum concentration of 7α-hydroxy-4-cholesten-3-one (C4), a marker of cholesterol 7α-hydroxylase activity, has recently become an attractive diagnostic tool for researchers interested in cholesterol and bile acid metabolism. The rapidly increasing demand of C4 measurement led to the development of various fast, mostly mass spectrometry-based analytical methods. Our aim was to compare four simple (i.e., not requiring solid phase extraction) extraction procedures (two "one-phase", and two "two-phase") in terms of basic analytical performance and their labouriousness. All methods exhibited comparable extraction recoveries (ranging from 88 to 97%) and intra-assay precision (variation coefficients below 10%), and failed in the removal of phospholipids. Although marked differences were observed in desalting and Deproteination, all methods can be considered satisfactory. Simple acetonitrile precipitation can be recommended if a fast extraction and minimal hands-on time is preferred; while two-phase ammonium sulphate:acetonitrile extraction should be chosen when maximal Deproteination is required.
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Comparison of simple extraction procedures in liquid chromatographymass spectrometry based determination of serum 7α-hydroxy-4-cholesten-3-one, a surrogate marker of bile acid synthesis
Journal of Chromatography B, 2016Co-Authors: Martin LeníĿek, Marek Vecka, Kateſina Žížalová, Libor VítekAbstract:Abstract The serum concentration of 7α-hydroxy-4-cholesten-3-one (C4), a marker of cholesterol 7α-hydroxylase activity, has recently become an attractive diagnostic tool for researchers interested in cholesterol and bile acid metabolism. The rapidly increasing demand of C4 measurement led to the development of various fast, mostly mass spectrometry-based analytical methods. Our aim was to compare four simple (i.e., not requiring solid phase extraction) extraction procedures (two ⿿one-phase⿿, and two ⿿two-phase⿿) in terms of basic analytical performance and their labouriousness. All methods exhibited comparable extraction recoveries (ranging from 88 to 97%) and intra-assay precision (variation coefficients below 10%), and failed in the removal of phospholipids. Although marked differences were observed in desalting and Deproteination, all methods can be considered satisfactory. Simple acetonitrile precipitation can be recommended if a fast extraction and minimal hands-on time is preferred; while two-phase ammonium sulphate:acetonitrile extraction should be chosen when maximal Deproteination is required.
Josef Winter - One of the best experts on this subject based on the ideXlab platform.
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Pilot-scale chitin extraction from shrimp shell waste by Deproteination and decalcification with bacterial enrichment cultures.
Applied microbiology and biotechnology, 2015Co-Authors: Mini Bajaj, Josef Winter, Andrea Freiberg, Claudia GallertAbstract:Extraction of chitin from mechanically pre-purified shrimp shells can be achieved by successive NaOH/HCl treatment, protease/HCl treatment or by environmentally friendly fermentation with proteolytic/lactic acid bacteria (LAB). For the last mentioned alternative, scale-up of shrimp shell chitin purification was investigated in 0.25 L (F1), 10 L (F2), and 300 L (F3) fermenters using an anaerobic, chitinase-deficient, proteolytic enrichment culture from ground meat for Deproteination and a mixed culture of LAB from bio-yoghurt for decalcification. Protein removal in F1, F2, and F3 proceeded in parallel within 40 h at an efficiency of 89-91 %. Between 85 and 90 % of the calcit was removed from the shells by LAB in another 40 h in F1, F2, and F3. After Deproteination of shrimp shells in F3, spent fermentation liquor was re-used for a next batch of 30-kg shrimp shells in F4 (300 L) which eliminated 85.5 % protein. The purity of the resulting chitin was comparable in F1, F2, F3, and F4. Viscosities of chitosan, obtained after chitin deacetylation and of chitin, prepared biologically or chemically in the laboratory, were much higher than those of commercially available chitin and chitosan.
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Transformation of the matrix structure of shrimp shells during bacterial Deproteination and demineralization
Microbial cell factories, 2013Co-Authors: Mini Bajaj, Josef Winter, Reinhard Schneider, Stephan L. Grage, Anne S. Ulrich, Claudia GallertAbstract:After cellulose and starch, chitin is the third-most abundant biopolymer on earth. Chitin or its deacetylated derivative chitosan is a valuable product with a number of applications. It is one of the main components of shrimp shells, a waste product of the fish industry. To obtain chitin from Penaeus monodon, wet and dried shrimp shells were deproteinated with two specifically enriched proteolytic cultures M1 and M2 and decalcified by in-situ lactic acid forming microorganisms. The viscosity of biologically processed chitin was compared with chemically processed chitin. The former was further investigated for purity, structure and elemental composition by several microscopic techniques and 13C solid state NMR spectroscopy. About 95% of the protein of wet shrimp shells was removed by proteolytic enrichment culture M2 in 68 h. Subsequent decalcification by lactic acid bacteria (LAB) took 48 h. Deproteination of the same amount of dried shrimps that contained a 3 × higher solid content by the same culture was a little bit faster and was finished after 140 h. The viscosity of chitin was in the order of chemically processed chitin > bioprocessed chitin > commercially available chitin. Results revealed changes in fine structure and chemical composition of the epi-, exo- and endocuticle of chitin from shrimp shells during microbial Deproteination and demineralization. From transmission electron microscopy (TEM) overlays and electron energy loss spectroscopy (EELS) analysis, it was found that most protein was present in the exocuticle, whereas most chitin was present in the endocuticle. The calcium content was higher in the endocuticle than in the exocuticle.13C solid state NMR spectra of different chitin confirmed
-
effect of Deproteination and deacetylation conditions on viscosity of chitin and chitosan extracted from crangon crangon shrimp waste
Biochemical Engineering Journal, 2011Co-Authors: Mini Bajaj, Josef Winter, Claudia GallertAbstract:Abstract Deproteination of decalcified chitin from Crangon crangon shells and deacetylation to chitosan was investigated to find out optimum conditions for a high viscosity chitosan. Deproteination was carried out with an optimum shrimp shell:alkali (s:a) ratio of 1:4 from 30 °C to 65 °C and at each temperature, incubation times were varied from 2 to 5 h for maximal efficiency. Viscosity of the chemically extracted chitin samples at different temperature–time conditions ranged from 195 to 391 mPa s. A two-way ANOVA with Bonferroni post test was performed on experimental data. Chitin extracted at various temperatures and incubation times was deacetylated with 50% (w/w) NaOH at increasing reaction times. The highest chitosan viscosity of 1976 mPa s was observed in a sample deproteinated for 5 h at 55 °C and deacetylated for 1 h at 105 °C and 2 bar N 2 pressure. One-way ANOVA test for chitosan viscosity measurements indicated a significant P value of
Martin LeníĿek - One of the best experts on this subject based on the ideXlab platform.
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Comparison of simple extraction procedures in liquid chromatography-mass spectrometry based determination of serum 7α-hydroxy-4-cholesten-3-one, a surrogate marker of bile acid synthesis.
Journal of chromatography. B Analytical technologies in the biomedical and life sciences, 2016Co-Authors: Martin LeníĿek, Marek Vecka, Kateſina Žížalová, Libor VítekAbstract:The serum concentration of 7α-hydroxy-4-cholesten-3-one (C4), a marker of cholesterol 7α-hydroxylase activity, has recently become an attractive diagnostic tool for researchers interested in cholesterol and bile acid metabolism. The rapidly increasing demand of C4 measurement led to the development of various fast, mostly mass spectrometry-based analytical methods. Our aim was to compare four simple (i.e., not requiring solid phase extraction) extraction procedures (two "one-phase", and two "two-phase") in terms of basic analytical performance and their labouriousness. All methods exhibited comparable extraction recoveries (ranging from 88 to 97%) and intra-assay precision (variation coefficients below 10%), and failed in the removal of phospholipids. Although marked differences were observed in desalting and Deproteination, all methods can be considered satisfactory. Simple acetonitrile precipitation can be recommended if a fast extraction and minimal hands-on time is preferred; while two-phase ammonium sulphate:acetonitrile extraction should be chosen when maximal Deproteination is required.
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Comparison of simple extraction procedures in liquid chromatographymass spectrometry based determination of serum 7α-hydroxy-4-cholesten-3-one, a surrogate marker of bile acid synthesis
Journal of Chromatography B, 2016Co-Authors: Martin LeníĿek, Marek Vecka, Kateſina Žížalová, Libor VítekAbstract:Abstract The serum concentration of 7α-hydroxy-4-cholesten-3-one (C4), a marker of cholesterol 7α-hydroxylase activity, has recently become an attractive diagnostic tool for researchers interested in cholesterol and bile acid metabolism. The rapidly increasing demand of C4 measurement led to the development of various fast, mostly mass spectrometry-based analytical methods. Our aim was to compare four simple (i.e., not requiring solid phase extraction) extraction procedures (two ⿿one-phase⿿, and two ⿿two-phase⿿) in terms of basic analytical performance and their labouriousness. All methods exhibited comparable extraction recoveries (ranging from 88 to 97%) and intra-assay precision (variation coefficients below 10%), and failed in the removal of phospholipids. Although marked differences were observed in desalting and Deproteination, all methods can be considered satisfactory. Simple acetonitrile precipitation can be recommended if a fast extraction and minimal hands-on time is preferred; while two-phase ammonium sulphate:acetonitrile extraction should be chosen when maximal Deproteination is required.