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Athanasios A. Koutinas - One of the best experts on this subject based on the ideXlab platform.
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succinic acid production by immobilized cultures using spent sulphite liquor as fermentation medium
Bioresource Technology, 2017Co-Authors: Maria Alexandri, Harris Papapostolou, Lutgart Stragier, Seraphim Papanikolaou, Willy Verstraete, Athanasios A. KoutinasAbstract:Abstract Spent sulphite liquor (SSL) was used as carbon source for the production of succinic acid using immobilized cultures of Actinobacillus succinogenes and Basfia succiniciproducens on two different supports, delignified Cellulosic Material (DCM) and alginate beads. Fed-batch immobilized cultures with A. succinogenes in alginates resulted in higher sugar to succinic acid conversion yield (0.81 g/g) than the respective yield achieved (0.65 g/g) when DCM immobilized cultures were used. The final succinic acid concentration and yield achieved in fed-batch with immobilized cultures of B. succiniciproducens in alginates (45 g/L and 0.66 g/g) were higher than A. succinogenes immobilized cultures (35.4 g/L and 0.61 g/g) using nano-filtrated SSL as fermentation medium. Immobilized cultures of B. succiniciproducens in alginate beads were reused in four sequential fed-batch fermentations of nano-filtrated SSL leading to the production of 64.7 g of succinic acid with a yield range of 0.42–0.67 g/g and productivity range of 0.29–0.65 g/L/h. The immobilized cultures improved the efficiency of succinic acid production as compared to free cell cultures.
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tubular cellulose starch gel composite as food enzyme storehouse
Food Chemistry, 2015Co-Authors: Eleftheria Barouni, Theano Petsi, Maria Kanellaki, Argyro Bekatorou, Athanasios A. KoutinasAbstract:Abstract The objective of this study was to produce a composite biocatalyst, based on porous Cellulosic Material, produced after wood sawdust delignification (tubular cellulose; TC) and starch gel (SG), for the development of bioprocesses related to enzyme applications. The composite biocatalyst was studied by Scanning Electron Microscopy to observe the SG deposition in the TC pores, and porosimetry analysis to determine the average pore diameter and surface area. The deposition of SG into the TC tubes provided a TC/SG composite with reduced pore sizes. X-ray powder diffractometry showed a decrease of crystallinity with increased SG ratio in the composite. The composite was used as an insoluble carrier for entrapment of the dairy enzyme rennin, leading to the production of an active biocatalyst for milk coagulation (initiation of milk clotting at about 20 min and full coagulation at about 200 min), creating perspectives for several applications in food enzyme research and technology.
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saccharomyces cerevisiae and oenococcus oeni immobilized in different layers of a cellulose starch gel composite for simultaneous alcoholic and malolactic wine fermentations
Process Biochemistry, 2013Co-Authors: Ioannis Servetas, Poonam Singh Nee Nigam, Argyro Bekatorou, Carmen Berbegal, Nathalia Camacho, Sergi Ferrer, Chryssoula Drouza, Athanasios A. KoutinasAbstract: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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oenococcus oeni cells immobilized on delignified Cellulosic Material for malolactic fermentation of wine
Bioresource Technology, 2008Co-Authors: Nikolaos Agouridis, Athanasios A. Koutinas, Nikolaos Kopsahelis, Stavros Plessas, Maria KanellakiAbstract:Abstract Oenococcus oeni ATCC 23279 cells immobilized on delignified Cellulosic Material (DCM) were used for malolactic fermentation (MLF). In first, eleven repeated alcoholic fermentation batches of white must of 11–12 °Be initial density were performed by Saccharomyces cerevisiae cells immobilized on delignified Cellulosic Material at 20 °C. Subsequently, the induction of MLF in the eleven taken wine batches by O. oeni cells immobilized on DCM took place at 27 °C. From the 3rd MLF batch up to 10th, the malic acid degradation was 53.1 up to 67.4% and the cfu of the immobilized cells/g of biocatalyst remained stable. The produced lactic acid was less than the stoichiometric yield and acetic acid content was significantly reduced after MLF not contributing in an important increase of the volatile acidity of wine. Ethanol, higher alcohols acetaldehyde and diacetyl contents in wines after MLF were in acceptable levels.
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investigation of volatiles evolution during the alcoholic fermentation of grape must using free and immobilized cells with the help of solid phase microextraction spme headspace sampling
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Athanasios Mallouchos, Athanasios A. Koutinas, Michael Komaitis, Maria KanellakiAbstract:A biocatalyst was prepared by immobilization of Saccharomyces cerevisiae strain AXAZ-1 on delignified Cellulosic Material (DCM). Repeated batch fermentations were conducted using these biocatalysts and free cells, separately, at temperatures of 20, 15, and 10 degrees C. Solid phase microextraction (SPME) was used in monitoring the formation of volatile alcohols, acetate esters, and ethyl esters of fatty acids. The kinetics of volatile production were similar for free and immobilized cells. In all cases immobilized cells showed a better rate of volatile production, which was directly connected to sugar consumption. The main difference observed was in propanol production, which increased with temperature decrease for the immobilized cells, whereas it remained constant for the free ones. In the case of immobilized cells significant amounts of esters were also produced. It is well-known that esters contribute to the fruity aroma of wine. It was also established that SPME is a very sensitive, accurate, and reliable technique and can be used without any reservation in the characterization of volatile constituents of wine.
Maria Kanellaki - One of the best experts on this subject based on the ideXlab platform.
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tubular cellulose starch gel composite as food enzyme storehouse
Food Chemistry, 2015Co-Authors: Eleftheria Barouni, Theano Petsi, Maria Kanellaki, Argyro Bekatorou, Athanasios A. KoutinasAbstract:Abstract The objective of this study was to produce a composite biocatalyst, based on porous Cellulosic Material, produced after wood sawdust delignification (tubular cellulose; TC) and starch gel (SG), for the development of bioprocesses related to enzyme applications. The composite biocatalyst was studied by Scanning Electron Microscopy to observe the SG deposition in the TC pores, and porosimetry analysis to determine the average pore diameter and surface area. The deposition of SG into the TC tubes provided a TC/SG composite with reduced pore sizes. X-ray powder diffractometry showed a decrease of crystallinity with increased SG ratio in the composite. The composite was used as an insoluble carrier for entrapment of the dairy enzyme rennin, leading to the production of an active biocatalyst for milk coagulation (initiation of milk clotting at about 20 min and full coagulation at about 200 min), creating perspectives for several applications in food enzyme research and technology.
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oenococcus oeni cells immobilized on delignified Cellulosic Material for malolactic fermentation of wine
Bioresource Technology, 2008Co-Authors: Nikolaos Agouridis, Athanasios A. Koutinas, Nikolaos Kopsahelis, Stavros Plessas, Maria KanellakiAbstract:Abstract Oenococcus oeni ATCC 23279 cells immobilized on delignified Cellulosic Material (DCM) were used for malolactic fermentation (MLF). In first, eleven repeated alcoholic fermentation batches of white must of 11–12 °Be initial density were performed by Saccharomyces cerevisiae cells immobilized on delignified Cellulosic Material at 20 °C. Subsequently, the induction of MLF in the eleven taken wine batches by O. oeni cells immobilized on DCM took place at 27 °C. From the 3rd MLF batch up to 10th, the malic acid degradation was 53.1 up to 67.4% and the cfu of the immobilized cells/g of biocatalyst remained stable. The produced lactic acid was less than the stoichiometric yield and acetic acid content was significantly reduced after MLF not contributing in an important increase of the volatile acidity of wine. Ethanol, higher alcohols acetaldehyde and diacetyl contents in wines after MLF were in acceptable levels.
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investigation of volatiles evolution during the alcoholic fermentation of grape must using free and immobilized cells with the help of solid phase microextraction spme headspace sampling
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Athanasios Mallouchos, Athanasios A. Koutinas, Michael Komaitis, Maria KanellakiAbstract:A biocatalyst was prepared by immobilization of Saccharomyces cerevisiae strain AXAZ-1 on delignified Cellulosic Material (DCM). Repeated batch fermentations were conducted using these biocatalysts and free cells, separately, at temperatures of 20, 15, and 10 degrees C. Solid phase microextraction (SPME) was used in monitoring the formation of volatile alcohols, acetate esters, and ethyl esters of fatty acids. The kinetics of volatile production were similar for free and immobilized cells. In all cases immobilized cells showed a better rate of volatile production, which was directly connected to sugar consumption. The main difference observed was in propanol production, which increased with temperature decrease for the immobilized cells, whereas it remained constant for the free ones. In the case of immobilized cells significant amounts of esters were also produced. It is well-known that esters contribute to the fruity aroma of wine. It was also established that SPME is a very sensitive, accurate, and reliable technique and can be used without any reservation in the characterization of volatile constituents of wine.
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high temperature alcoholic fermentation of whey using kluyveromyces marxianus imb3 yeast immobilized on delignified Cellulosic Material
Bioresource Technology, 2002Co-Authors: Yiannis Kourkoutas, Poonam Singh Nee Nigam, Maria Kanellaki, Roger Marchant, Ibrahim M Banat, S Dimitropoulou, Athanasios A. KoutinasAbstract:A novel system for high-temperature alcoholic fermentation of whey is described. This system consists of Kluyveromyces marxianus yeast immobilized on delignified Cellulosic Material (DCM). The effect of pH, initial lactose concentration and temperature on the fermentation of a synthetic medium containing lactose was studied. Batch fermentations of whey were also carried out and the formation of volatile by-products was examined. The concentrations of higher alcohols were found to be in very low levels leading to a product of improved quality. The fermented whey had an improved characteristic aroma compared to unfermented whey. The possibility to use fermented whey as raw Material for the production of a novel, low alcohol content drink was also investigated.
Shakeel Ahmed Khan - One of the best experts on this subject based on the ideXlab platform.
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cellulase production from aspergillus niger ms82 effect of temperature and ph
New Biotechnology, 2009Co-Authors: Muhammad Sohail, Roquya Siddiqi, Aqeel Ahmad, Shakeel Ahmed KhanAbstract:Abstract Fungal cellulases are well-studied enzymes and are used in various industrial processes. Much of the knowledge of enzymatic depolymerization of Cellulosic Material has come from Trichoderma cellulase system. Species of Trichoderma can produce substantial amounts of endoglucanase and exoglucanase but very low levels of β-glucosidase. This deficiency necessitates screening of fungi for cellulytic potential. A number of indigenously isolated fungi were screened for cellulytic potential. In the present study, the kinetics of cellulase production from an indigenous strain of Aspergillus niger MS82 is reported. Product formation parameters of endoglucanase and β-glucosidase ( Q p + Y p/s ) indicate that A. niger MS82 is capable of producing moderate to high levels of both endoglucanase and β-glucosidase when grown on different carbon containing natural substrates, for example, grass, corncob, bagasse along side purified celluloses. Furthermore, it was observed that the production of endoglucanase reaches its maximum during exponential phase of growth, while β-glucosidase during the Stationary phase. Enzyme production by solid-state fermentation was also investigated and found to be promising. Highest production of cellulase was noted at pH 4.0 at 35 °C under submerged conditions. Growth and enzyme production was affected by variations in temperature and pH.
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cellulase production from aspergillus niger ms82 effect of temperature and ph
New Biotechnology, 2009Co-Authors: Muhammad Sohail, Roquya Siddiqi, Aqeel Ahmad, Shakeel Ahmed KhanAbstract:Fungal cellulases are well-studied enzymes and are used in various industrial processes. Much of the knowledge of enzymatic depolymerization of Cellulosic Material has come from Trichoderma cellulase system. Species of Trichoderma can produce substantial amounts of endoglucanase and exoglucanase but very low levels of b-glucosidase. This deficiency necessitates screening of fungi for cellulytic potential. A number of indigenously isolated fungi were screened for cellulytic potential. In the present study, the kinetics of cellulase production from an indigenous strain of Aspergillus niger MS82 is reported. Product formation parameters of endoglucanase and beta-glucosidase (Qp + Y(p/s)) indicate that A.niger MS82 is capable of producing moderate to high levels of both endoglucanase and beta-glucosidase when grown on different carbon containing natural substrates, for example, grass, corncob, bagasse along side purified celluloses. Furthermore, it was observed that the production of endoglucanase reaches its maximum during exponential phase of growth, while b-glucosidase during the Stationary phase. Enzyme production by solid-state fermentation was also investigated and found to be promising.Highest production of cellulase was noted at pH 4.0 at 35 degrees C under submerged conditions. Growth and enzyme production was affected by variations in temperature and pH.
Muhammad Sohail - One of the best experts on this subject based on the ideXlab platform.
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cellulase production from aspergillus niger ms82 effect of temperature and ph
New Biotechnology, 2009Co-Authors: Muhammad Sohail, Roquya Siddiqi, Aqeel Ahmad, Shakeel Ahmed KhanAbstract:Abstract Fungal cellulases are well-studied enzymes and are used in various industrial processes. Much of the knowledge of enzymatic depolymerization of Cellulosic Material has come from Trichoderma cellulase system. Species of Trichoderma can produce substantial amounts of endoglucanase and exoglucanase but very low levels of β-glucosidase. This deficiency necessitates screening of fungi for cellulytic potential. A number of indigenously isolated fungi were screened for cellulytic potential. In the present study, the kinetics of cellulase production from an indigenous strain of Aspergillus niger MS82 is reported. Product formation parameters of endoglucanase and β-glucosidase ( Q p + Y p/s ) indicate that A. niger MS82 is capable of producing moderate to high levels of both endoglucanase and β-glucosidase when grown on different carbon containing natural substrates, for example, grass, corncob, bagasse along side purified celluloses. Furthermore, it was observed that the production of endoglucanase reaches its maximum during exponential phase of growth, while β-glucosidase during the Stationary phase. Enzyme production by solid-state fermentation was also investigated and found to be promising. Highest production of cellulase was noted at pH 4.0 at 35 °C under submerged conditions. Growth and enzyme production was affected by variations in temperature and pH.
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cellulase production from aspergillus niger ms82 effect of temperature and ph
New Biotechnology, 2009Co-Authors: Muhammad Sohail, Roquya Siddiqi, Aqeel Ahmad, Shakeel Ahmed KhanAbstract:Fungal cellulases are well-studied enzymes and are used in various industrial processes. Much of the knowledge of enzymatic depolymerization of Cellulosic Material has come from Trichoderma cellulase system. Species of Trichoderma can produce substantial amounts of endoglucanase and exoglucanase but very low levels of b-glucosidase. This deficiency necessitates screening of fungi for cellulytic potential. A number of indigenously isolated fungi were screened for cellulytic potential. In the present study, the kinetics of cellulase production from an indigenous strain of Aspergillus niger MS82 is reported. Product formation parameters of endoglucanase and beta-glucosidase (Qp + Y(p/s)) indicate that A.niger MS82 is capable of producing moderate to high levels of both endoglucanase and beta-glucosidase when grown on different carbon containing natural substrates, for example, grass, corncob, bagasse along side purified celluloses. Furthermore, it was observed that the production of endoglucanase reaches its maximum during exponential phase of growth, while b-glucosidase during the Stationary phase. Enzyme production by solid-state fermentation was also investigated and found to be promising.Highest production of cellulase was noted at pH 4.0 at 35 degrees C under submerged conditions. Growth and enzyme production was affected by variations in temperature and pH.
A Gauthier - One of the best experts on this subject based on the ideXlab platform.
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comparative study of ligno Cellulosic Material from wheat straw and of pure and mixed standard compounds via solid state 13c nmr spectroscopy conventional pyrolysis and tmah thermochemolysis
Journal of Analytical and Applied Pyrolysis, 2003Co-Authors: A Gauthier, Sylvie Derenne, Claude Largeau, Laurent Dupont, Emmanuel Guillon, Jacques Dumonceau, Michel AplincourtAbstract:Abstract The ligno-Cellulosic Material (LCS) isolated from wheat straw, via successive acid and base treatments, exhibits high complexing capacities, mostly related to the lignin fraction, and may have important applications for metal completion. In the present study LCS was examined via a combination of spectroscopic and pyrolytic methods: solid slate cross polarization/magic angle spinning 13C nuclear magnetic resonance (CP/MAS 13C NMR), conventional Curie point pyrolysis–gas chromatography–mass spectrometry (CuPy–GC–MS) and tetramethylammonium hydroxide (TMAH) thermochemolysis–GC–MS). Parallel experiments were also performed on cellulose and tignin standards and 50:50 cellulose:lignin mixture. These studies afforded information on lignin:cellulose relative abundances in LCS (ca. 15:85) and on the composition of the lignin fraction, including the presence of substantial amounts of carboxylic groups which should be important for metal complexation. Examination of standards and mixture also illustrated (i) the usefulness of TMAH thermochemolysis for the detection of cellulose and of carboxylic groups compared with conventional pyrolysis and (ii) the conspicuous limitations of some of the above methods when applied to ligno-Cellulosic Materials and resulting biases.