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Kerovuo, Janne. "A novel phytase from Bacillus : characterization and production of the enzyme". Helsinki : University of Helsinki, 2000. http://ethesis.helsinki.fi/julkaisut/mat/bioti/vk/kerovuo/.
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Moss, Amy F. "Nutritional strategies to enhance the efficiency of chicken-meat production". Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/20031.
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There is, of necessity, an ongoing quest to develop nutritional strategies to enhance chicken-meat production to meet the growing global demand. A better appreciation of starch and protein digestive dynamics is one such strategy. Digestive dynamics is the balance of protein and starch digestion, amino acid and glucose absorption, and the transition of nutrients across enterocytes into the portal circulation and to the sites of protein deposition. Protein and starch digestive dynamics are important for efficient lean muscle deposition. Phytase inclusion and whole grain feeding are two more nutritional strategies that are widely adopted by the Australian chicken-meat industry in tandem and both may influence protein and starch digestive dynamics. Thus, it is important to examine all three in tandem as is done within this thesis. The hallmark response of whole grain feeding regimes are heavier relative gizzard weights, and the gizzard is the prime site of phytate degradation by exogenous phytase. Therefore, whole grain feeding regimes should improve gizzard functionality and thereby facilitate phytate degradation by exogenous phytase. Nevertheless, there is a paucity of whole grain feeding studies examining protein/starch digestibility, digesta passage rates or protein/starch digestive dynamics. Phytase is reported to improve amino acid digestibilities and to effect a ‘proximal shift’ in the sites of amino acid absorption. However, the potential influence of phytase on amino acid and glucose absorption and transition into the portal circulation is yet to be investigated. Therefore, the objective of this thesis is to evaluate phytase inclusion and whole grain feeding regimes separately and in tandem within a digestive dynamics context to identify nutritional strategies with the capacity to enhance the efficiency of chicken-meat production.
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Spier, Michele Rigon, Adenise Lorenci Woiciechowski, Carlos Ricardo 1953 Soccol i Universidade Federal do Paraná Setor de Tecnologia Programa de Pós-Graduaçao em Processos Biotecnológicos. "Development of a bioprocess for production of a new A. niger FS3 Phytase". reponame:Repositório Institucional da UFPR, 2009. http://hdl.handle.net/1884/18314.
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Tang, Shuiquan. "Process engineering of Pichia pastoris cultivation for the production of a phytase with GAP promoter". Thesis, University of Ottawa (Canada), 2009. http://hdl.handle.net/10393/28277.
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Pichia pastoris (P. pastoris) is a popular host for recombinant protein production. In this work, phytase production with P. pastoris under GAP promoter was studied. In the first part of this study, feasibility of using crude glycerol from biodiesel production as the sole carbon source for P. pastoris cultivation was investigated. Although growth inhibition was found in batch cultivations stated with high concentration of biodiesel glycerol, efficient high cell density production was realized by fed-batch cultivation started with a low concentration of biodiesel glycerol. The second part of this work focused on the study of growth kinetics with continuous cultivations under different dilution rates. The influences of dilution rate upon cell growth and phytase production were revealed and characterized with empirical equations. Based on these results, a simple kinetic model was established and model parameters were estimated mainly based on these results as well. Good agreement with experimental results was found when this model was applied to the prediction of cell growth and phytase production in regular fed-batch cultivation processes.
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Zhong, Shuping. "Study of Operational Strategies and Carbon Source Selection for the Production of Phytase using Pichia pastoris". Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32204.
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The methylotrophic yeast Pichia pastoris has become an efficient expression system for heterologous protein production. Different methods have been studied to enhance cell growth as well as the production of products of interest. Two of the major strategies for improving the product or biomass yields are optimizing bioprocess controls and cultivation conditions. In this work, the characteristics of this yeast system and of its different promoters are discussed, and the effect of operational strategies on cell growth and recombinant protein expression is also studied. The effect of different feeding strategies were studied and optimized for pGAP (glyceraldehyde-3-phosphate dehydrogenase)-regulated phytase production in P. pastoris. Alternative carbon sources were screened and the feasibility of using citric acid as a carbon source for recombinant protein production was also investigated. The effects of parameters such as the carbon source concentration and culture pH were studied using shake-flasks, and the effect of different feeding profiles on bioreactor performance was also investigated. Three feeding strategies, Stepwise feeding, Exponential feeding and DO-stat feeding were tested and DO-stat was found to be more efficient and led to a high phytase activity. A modified DO-stat method was investigated to overcome the oxygen limited condition in the standard DO-stat method. For the carbon source, citric acid showed promise in improving phytase expression. Further experiments in bioreactors performed with the
presence of certain amount of citric acid showed that less glycerol could be used to achieve the same level of phytase activity.
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Ebune, Anne Ebane. "Production of phytase and reduction of phytic acid content in canola meal by solid state fermentation". Thesis, University of Ottawa (Canada), 1992. http://hdl.handle.net/10393/10855.
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A static state technique for fermentation was applied using Aspergillus ficuum NRRL 3135 on canola meal for the production of phytase and for the reduction of the phytic acid content in the meal. Aspergillus ficuum was chosen as a result of its high phytase producing capacity. In the study of the effects of physical and nutritional factors on the enzyme production and the phytic acid content reduction, it was found that moisture content was a critical factor and 64% water in the medium was found to be the optimum moisture content for both enzyme production and phytic acid content reduction. Increasing time of homogenization of inoculum up to 240 seconds improved enzyme production and phytic acid reduction. Increase in both inoculum concentration (biomass) and inoculum age up to 7-days old increased enzyme production and rate of phytic acid content reduction. With increase in initial pH of medium of up to 5.7, increased enzyme production and rate of phytic acid reduction were achieved. In the addition of surfactants to medium, sodium oleate was found to significantly increase enzyme production and the rate of phytic acid content reduction while Triton X-100 gave a negative effect. The addition of 1 mg phosphate remarkably increased the enzyme production and phytic acid content reduction; though a negative effect was obtained for systems containing combined portions of oleate and phosphate. Biomass in the solid culture was found to increase during fermentation up to 144 h of incubation and the protein content of culture also increased to about 18% after 96 h of incubation; hence this method of fermentation could be used to improve the nutritional quality of the meal for animal feed.
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Al-Asheh, Sameer. "Production of phytase and reduction of phytic acid content in canola meal by solid state fermentation using Aspergillus carbonarius". Thesis, University of Ottawa (Canada), 1993. http://hdl.handle.net/10393/7578.
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Solid state fermentation (SSF) with canola meal as substrate was carried out to study the production of phytase and the reduction of the phytic acid content in the meal using Aspergillus carbonarius NRC 401124. Some characteristics of the phytase were studied. $K\sb{\rm m}$ and $\nu\sb{max}$ values of 0.345 mM and 0.8071 units were determined when sodium phytate was used as the substrate for this enzyme. The enzyme showed an optimum pH and temperature of 4.7 and 53$\sp\circ$C respectively. It was found that the production of phytase was growth associated and that the maximum activity was attained after 72 h of incubation during SSF process. Apparent increases of about 25% and 10% of protein content of canola meal were noticed after 48 h and 72 h of the process respectively. A 25% reduction in the total carbohydrate concentration was reached at the end of fermentation. The rate of the reduction of phytic acid content of the meal depended on the physical parameters of the SSF. The optimum particle size of the meal for this process was found to be 1.4 mm, and negative results are noticed with particle sizes higher than 1.4 mm. It was found that the increase in glucose amount up to and including 6 g per system in the initial medium resulted in an increase in the rate of the biomass growth, enzyme concentration and the rate of phytic acid content reduction in canola meal. The addition of 1 mg of phosphate per system remarkably increased the biomass and enzyme productions and phytic acid content reduction. Sodium oleate increased the biomass and enzyme productions and the rate of phytic acid content reduction, while Triton X-100 gave a negative effect. (Abstract shortened by UMI.)
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Contreras, Tobar Edith Andrea. "Evaluación productiva de una fitasa de origen microbiano (Ronozyme ® Phytase) en dietas de pollos Broiler". Tesis, Universidad de Chile, 2001. http://repositorio.uchile.cl/handle/2250/132085.
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Memoria para optar al Título Profesional de Médico VeterinarioSe investigó el efecto de la incorporación de una fitasa comercial de origen microbiano (Ronozyme® Phytase) en dietas de pollos broiler. Se evaluó el comportamiento productivo de las aves mediante un experimento de 43 días de duración en que se utilizaron seis mil pollos broiler Ross 308 de 1 día de edad, 50% machos y 50% hembras. El experimento consistió en 4 tratamientos: 1) Dieta control sin adición de fitasa; 2) Dieta control mas fitasa (750 FTU de fitasa/kg de dieta) en reemplazo de un 0,1% del fósforo total proveniente del fosfato de calcio; 3) Dieta formulada con los mismos ingredientes de la dieta control con la adición de 750 FTU de fitasa/kg de dieta, considerando un aporte nutritivo de la fitasa de 13 kcal/kg de EMAn, 0,35% de proteína, 0,013% de lisina, 0,009% de metionina+cistina, 0,1% de Ca y 0,1% de P total, valores que se descontaron del aporte nutritivo total de la dieta; 4) Dieta idéntica al tratamiento 3, descontados los valores nutricionales recién señalados, pero sin adición de fitasa. A lo largo del experimento se utilizaron 3 dietas para cada tratamiento según los siguientes períodos: inicial (1 a 21 días); intermedia (22 a 38 días) y final (39 a 43 días). Todas las dietas fueron formuladas a base de maíz, afrecho de soya, gluten de maíz, harina de pescado y aceite vegetal. Los indicadores productivos controlados fueron peso vivo los días 1, 21 y 43, consumo de alimento, eficiencia de conversión alimenticia (ECA) y mortalidad a los 21 y 43 días de edad. Además, se calculó el porcentaje de cenizas en falanges de una muestra de 120 pollos por cada tratamiento al finalizar el período experimental. Adicionalmente, se registró el número de pollos que presentaron anormalidades esqueléticas que se manifestaron con un desplazamiento anormal de las aves a los 21 y 43 días de edad. La adición de fitasa en dietas de pollos broiler reemplazó el aporte parcial de fósforo (P) inorgánico, aminoácidos, proteína, Ca y energía metabolizable aparente corregida para nitrógeno (EMAn), sin afectar los indicadores productivos e integridad ósea de las aves. La reducción de EMAn, proteína, lisina, metionina+cistina, Ca y P de la dieta en ausencia de fitasa influyó negativamente sobre el rendimiento productivo de las aves de 1 a 43 días de edad. El cálculo económico realizado indica que la adición de 750 FTU de fitasa mejora la utilidad por pollo cuando la enzima sólo reemplaza 0,1% de P disponible de la dieta
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Misrahi, Audrey. "Transformation de végétaux par fermentation en milieu solide pour la production d'outils enzymatiques et de biomasse valorisée : application au couple "grain de maïs/Fusarium venenatum".Invertigations pour la production de phytases et de polysaccharidases". Université Louis Pasteur (Strasbourg) (1971-2008), 2007. http://www.theses.fr/2007STR13247.
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Un procédé de fermentation en milieu solide a été défini puis mis en place ; il met en œuvre le grain de maïs et le champignon Fusarium venenatum. Deux outils sont également développés : un dispositif de culture statique à petite échelle permettant des expériences répétables et des anticorps anti-Fusarium pour assurer un suivi hors ligne spécifique de la croissance du champignon. Le couple F. Venenatum/maïs grain est évalué pour la production de polysaccharidases (glucoamylases, xylanases, cellulases, pectinases) et de phytases. Le couple est retenu comme source d’un cocktail de polysaccharidases ou encore d’un mélange de phosphatases au spectre large de substrats, incluant probablement l’acide phytique. Une analyse par spectrométrie de masse d’un extrait de fermentation en milieu solide permet d’identifier les homologues polysaccharidases chez F. Graminearum produites par F. Venenatum. Les résultats ouvrent également d’autres voies d’investigation pour des produits commercialisablesWe developed a solid state fermentation process. It focuses on the growth of the fungus Fusarium venenatum on a substrate based on whole maize kernel. Designs of solid cultures have been used at the laboratory scale, to define the process and, further, assist its optimization. A specific solution of following the fungus growth has been found, which use antibody anti-Fusarium. F. Venenatum/maize kernel has been tested for its ability to produce polysaccharidases and phytases. This couple leads to the production of phosphatases with a probable large range of substrates, including phytic acid, but not to “strict” phytases. Its potential for the production of polysaccharidases has been confirmed, through enzymatic assay measurements and mass spectrometry experiments. Those ones used data on F. Graminearum’s proteins. Results also indicate other final products, as well as the production of a liquid extract rich in glucose, fungi proteins and inorganic phosphate
10
Wu, Pei-Hua, i 吳佩樺. "Production of Escherichia coli phytase by recombinant Pichia pastoris". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/38609423050340225335.
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碩士國立臺灣大學
農業化學研究所
88
Phytase, a valued feed additive for monogastric animals, has been used to hydrolyze phytic acid in feeds and to reduce the antinutrient ability of phytic acid. It also helps the release of phosphorous from phytic acid to increase phosphorous digestibility. In this study, the production of Escherichia coli phytase in recombinant Pichia pastoris KM 71-61 was investigated and the biochemical characteristics of said phytase were presented. By adding 0.5% methanol every 24 h during the stationary phase in the flask cultures, the phytase activity reached up to 150 U/ml after 144 h of induction. The phytase activity increased one fold in the case of replacing culture with fresh medium before induction. With the same strategy, the phytase activity is about 600 U/ml in fermentor cultures after 168 h of induction. The increase of phytase activity is not resulted from adding extra nutrients but from removing inhibitors. The phytase activity on cellular base was higher when initiated with lower cell density. The starvation before induction has little effect on the phytase activity due to the slow utilization of methanol in Pichia pastoris KM 71- 61.
11
Chen, Yu, i 陳褕. "Purification and immobilization phytase for the production of inositoll". Thesis, 1999. http://ndltd.ncl.edu.tw/handle/18804418671812097792.
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碩士國立東華大學
生物技術研究所
87
Phytase (myo-inositol hexakisphosphate phosphohydrolase) hydrolyzes phytic acid to myo-inositol and phosphoric acid. Two types of phytase are known: 3-phytase (E.C.3.1.3.8) and 6-phytase (E.C. 3.1.3.26) by indicating the phosphoester bond position of the first attack. It was reported that phytase activity was assayed by measuring the rate of increase in inorganic orthophosphate (pi) and the extracted phosphomolybdate. The method was used with the colorimetric measurements of the activity of phosphomolybdate . In this study, We used the concentration of inositol released from phytic acid to indicate the activity of this enzyme by monitoring the rate of inositol production using HPLC-RI detector. Phytases were prepared from E. coli K12 . The purification steps include cell culture, sonication, ammonium sulfate precipitation, Ion-exchange, and Gel-filtration chromatography. The final purity of phytase was 79.3 folds , and the maxium activity of the enzyme was 102.3 U/mg , when the enzyme reaction was under the condition：pH 4.5 and 55oC . The kinetic investigations showed that Vmax = 184μM/min; Km= 10.8 mM; Kcat = 200 min-1 at the optimum enzyme reactive conditions of pH 4.5, at 55 oC The tolerance limit for temperature was 55 oC. The production rate of inositol from phytic acid was 72.2 %. The immobilization of phytase was accomplished by using chitosan beads. The optimun enzyme absorbed was 0.38 mg / g bead . For the optimum reactive condition of immobilized enzyme was pH 4.5 and 60 oC; howevere, the enzyme activity had only 25.2 % of the free enzyme activity (Kcat) and the production rate of inositol from phytic acid was 25.5 %.
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Tseng, Shiann-Ming, i 曾憲明. "Production and Charaterization of Extracellular Phytase from Aspergillus ficuum mutant". Thesis, 1995. http://ndltd.ncl.edu.tw/handle/52652009923489204568.
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碩士國立中興大學
食品科學研究所
83
Eighty three microorganisms containing phytase activity were isolated from different sources of soil. Strain M46 was found to have the highest enzyme activity among these organisms. For further improvement, Aspergillus ficuum NRRL 3135 and strain M46 were treated with the mutagenic agent NTG (N-methyl-N-nitro-N'-nitrosoguanidine) and plated onto PSM agar containing calcium phytate as a selective medium. One of the NTG-treated strains, A. ficuum mutant A200413, showed considerably higher phytase activity than the parent strain A. ficuum NRRL 3135 and was chosen for further investigation. This mutant strain A200413 was cultivated in shaking flasks and the optimal medium for the phytase production by this strain were as follows: molasses, 12.93%; ammonium nitrate, 0.5%; KCl; 0.05%; MgSO4．7H2O, 0.05%; KH2PO4, 0.002%; FeSO4． 7H2O, 0.001%; and MnSO4．4H2O, 0.001%. For cuitivations, initial pH at 4.0, inoculum size at 10(7) spores/50 ml, incubation temperature at 35℃, and shaking rate at 150 rpm were found to be the optimal conditions. The maximal phytase activity of 5633.34 U/ml was obtained after 6 days of incubation under the optional conditions. The optimal temperature and pH for the crude ezyme activity of mutant A200413 were 58-60℃ and 5.5, respectively. This enzyme was stable at pH 2.0 and pH 4.0 and maintained 90% of its activity after incubated at 55℃ for 10 min. After 60 days of storage at -20℃, only 20% loss of enzyme activity was found. The activity of the crude phytase was found to be inhibited by Ag+, Cu2+, Fe3+, Mn2+, Na+, Zn2+ and oxalate, whereas the enzyme activity was increased by the presence of Mg2+, citrate and EDTA. Ca2+ and K+ had no effect on the catalytic rate of the crude phytase from strain A200413.
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Hsieh, Meng Chou, i 謝孟洲. "Estimation of simultaneous production for xylanase/phytase and optimal production of xylanase from Aspergillus carneus M34". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/46760344500471002172.
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碩士國立中興大學
食品科學系
92
The objective of this study was to evaluate the possibility of enhancement of xylanase and phytase activity simultaneously from Aspergillus carneus M34 and to establish the optimal conditions for xylanase production by using experimental design methodology. The effects of nutrition on the enzyme activity were evaluated, and then the important factors were selected through fractional factorial design. The steepest ascent design was used to establish the superior conditions for xylanase production. Effects of the phosphorous source, culture temperature, and initial pH on the xylanase activity were evaluated as well. The optimal enzyme activity was obtained by central composite design. The results from the phosphorous source, carbon source, and experiment design studies showed that both of xylanase and phytase activity could not be improved simultaneously by selecting the nutritional factors and their concentrations. Xylanase activity was estimated to be 11.66 U/ ml by the mathematic model of central composite design, and the stationary point was found to be a saddle point. The optimal conditions for the xylanase activity from A. carneus M34 are as follows: 1.5% hemicellulose (from coba husk), 0.8 % yeast extract, 0.4% ammonium chloride, initial pH at 7.00, incubation temperature at 30℃. After 5 days of cultivation, the maximal enzyme activity was 27.31±1.14 U/ ml.
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Chiang, Chen-Hua, i 蔣正華. "Studies on the production of inositol from phytic acid using immobilized phytase". Thesis, 1996. http://ndltd.ncl.edu.tw/handle/64096360752894236709.
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Chanderman, Ashira. "Production, characterisation and applications of a thermo-acid-stable phytase from Enterobacter sp. ACSS". Thesis, 2016. http://hdl.handle.net/10321/1745.
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Submitted in complete fulfillment for the Degree of Master of Applied Sciences in Biotechnology, Durban University of Technology, Durban, South Africa, 2016.A bacterial strain producing an extracellular phytase was identified as Enterobacter sp. ACSS. Optimization of process parameters using statistical methods such as Plackett-Burman design (PBD), the steepest ascent method, and response surface methodology (RSM) significantly improved phytase production by 4.6–fold in shake-flasks. In addition, an overall 1.9-fold increase in phytase production was attained in fed-batch fermentations in a 5 l laboratory fermenter, respectively. The purified 62 kDa phytase from Enterobacter sp. ACSS was active between 40 to 80°C and an acidic pH range of 2.0 to 6.0 with half-life of 693 and 577.5 min at 60°C and pH 2.0, respectively. Additionally, the enzyme is fairly stable with proteolytic enzymes under physiological conditions. It was activated by Ca+2, Mg+2 and Mn+2 while inhibition was caused by Zn+2, Cu+2, Fe+2, Pb+2, Co+2, Ba+2 and surfactants. The Km, Vmax and Kcat observed were 0.21 mM, 131.58 nmol mg-1s-1 and 1.64 × 103 s-1, respectively. The enzyme released inorganic phosphate from animal feed (4.0-6.62 mg/g of diet) and insoluble metal-phytates (45-219 µg/ml) and was effective in improving the characteristics of brown bread. Overall, this study shows that Enterobacter sp. ACSS has the potential to produce significant titres of a thermo- and acid-stable phytase and can be applied in dephytinizing animal feeds, and the baking industry.
M
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Shieh, I.-Chuan, i 謝衣鵑. "Studies on the production, partial purification and characterization of the phytase from penicillium simplicissimum W46". Thesis, 1996. http://ndltd.ncl.edu.tw/handle/72175918046161592751.
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Hong, Ya-Fang, i 洪雅芳. "Transgenic Potato and Sweet Potato for Production of High Efficiency Phytase for Use as Animal Feed Additive". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/07464458711963290932.
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Benchabane, Samir. "Production de microcapsules de phytase par atomisation: influence sur la disponibilité des nutriments chez la truite arc-en-ciel (Oncorhynchus mykiss) /". 2005. http://proquest.umi.com/pqdweb?did=1075706801&sid=3&Fmt=2&clientId=9268&RQT=309&VName=PQD.
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