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The objective of this investigation was to develop bread, with high nutritional and technological quality, using whole flour of Amaranthus spinosus and Amaranthus hypochondriacus. Bread quality was analyzed in terms of chemical composition, loaf specific volume, width/height ratio of the central slice, crust/crumb color, crumb structure and firmness, and sensory analysis. Starch thermal properties were studied in terms of enthalpies of starch gelatinization during baking and amylopectin retrogradation during storage. Incorporation of amaranth flour significantly increased protein, lipid, fiber, ash, and myo-inositol phosphate contents. Bread with amaranth flours exhibited soluble/insoluble fiber ratios close to 1:2, which presents the most effective physiological action. Intake of products with high substitution of amaranth could cover the protein requirement in adults, and could contribute substantially to intake of dietary fiber, Fe, and Zn according to daily recommendations. Bread with A. hypochondriacus showed higher acceptability than formulations with A. spinosus. Inclusion of amaranth allowed delaying and decreasing crumb staling in terms of amylopectin retrogradation. The inclusion of amaranth could be limited to a maximum of 25 g/100 g, with considerable nutritional improvement and acceptable sensory and technological quality, even during the staling process.

In order to understand the substrate specificity of protein tyrosine phosphatase-like myo-inositol phosphatases (PTPLPs), I have determined the structure of PhyA from Mitsuokella multacida (PhyAmm) and Selenomonas ruminantium (PhyAsr) in complex with multiple myo-inositol phosphates (IPs). These are the first atomic resolution structures of PTPLPs in complex with InsP5, InsP4, or InsP3 substrates, and represent four of the five known PTPLP:IP complex structures. Based on these structures, I have identified three structural features that determine the substrate specificity of PTPLPs. As part of this work, I demonstrate that the PhyAmm C-terminal repeat and PhyAsr bind substrates using conserved phosphoryl-binding sites. Further, I have determined the InsP6 hydrolysis pathways for several PTPLPs and present a novel IP specificity assay. With this assay, I identify that the two repeats of PhyAmm have divergent activities that clearly indicate a ’divide and conquer’ approach to maximize phosphoryl group removal from InsP6 and mixed IPs.

In order to understand the substrate specificity of protein tyrosine phosphatase-like myo-inositol phosphatases (PTPLPs), I have determined the structure of PhyA from Mitsuokella multacida (PhyAmm) and Selenomonas ruminantium (PhyAsr) in complex with multiple myo-inositol phosphates (IPs). These are the first atomic resolution structures of PTPLPs in complex with InsP5, InsP4, or InsP3 substrates, and represent four of the five known PTPLP:IP complex structures. Based on these structures, I have identified three structural features that determine the substrate specificity of PTPLPs. As part of this work, I demonstrate that the PhyAmm C-terminal repeat and PhyAsr bind substrates using conserved phosphoryl-binding sites. Further, I have determined the InsP6 hydrolysis pathways for several PTPLPs and present a novel IP specificity assay. With this assay, I identify that the two repeats of PhyAmm have divergent activities that clearly indicate a ’divide and conquer’ approach to maximize phosphoryl group removal from InsP6 and mixed IPs.

In order to understand the substrate specificity of protein tyrosine phosphatase-like myo-inositol phosphatases (PTPLPs), I have determined the structure of PhyA from Mitsuokella multacida (PhyAmm) and Selenomonas ruminantium (PhyAsr) in complex with multiple myo-inositol phosphates (IPs). These are the first atomic resolution structures of PTPLPs in complex with InsP5, InsP4, or InsP3 substrates, and represent four of the five known PTPLP:IP complex structures. Based on these structures, I have identified three structural features that determine the substrate specificity of PTPLPs. As part of this work, I demonstrate that the PhyAmm C-terminal repeat and PhyAsr bind substrates using conserved phosphoryl-binding sites. Further, I have determined the InsP6 hydrolysis pathways for several PTPLPs and present a novel IP specificity assay. With this assay, I identify that the two repeats of PhyAmm have divergent activities that clearly indicate a ’divide and conquer’ approach to maximize phosphoryl group removal from InsP6 and mixed IPs.

In order to understand the substrate specificity of protein tyrosine phosphatase-like myo-inositol phosphatases (PTPLPs), I have determined the structure of PhyA from Mitsuokella multacida (PhyAmm) and Selenomonas ruminantium (PhyAsr) in complex with multiple myo-inositol phosphates (IPs). These are the first atomic resolution structures of PTPLPs in complex with InsP5, InsP4, or InsP3 substrates, and represent four of the five known PTPLP:IP complex structures. Based on these structures, I have identified three structural features that determine the substrate specificity of PTPLPs. As part of this work, I demonstrate that the PhyAmm C-terminal repeat and PhyAsr bind substrates using conserved phosphoryl-binding sites. Further, I have determined the InsP6 hydrolysis pathways for several PTPLPs and present a novel IP specificity assay. With this assay, I identify that the two repeats of PhyAmm have divergent activities that clearly indicate a ’divide and conquer’ approach to maximize phosphoryl group removal from InsP6 and mixed IPs.

In order to understand the substrate specificity of protein tyrosine phosphatase-like myo-inositol phosphatases (PTPLPs), I have determined the structure of PhyA from Mitsuokella multacida (PhyAmm) and Selenomonas ruminantium (PhyAsr) in complex with multiple myo-inositol phosphates (IPs). These are the first atomic resolution structures of PTPLPs in complex with InsP5, InsP4, or InsP3 substrates, and represent four of the five known PTPLP:IP complex structures. Based on these structures, I have identified three structural features that determine the substrate specificity of PTPLPs. As part of this work, I demonstrate that the PhyAmm C-terminal repeat and PhyAsr bind substrates using conserved phosphoryl-binding sites. Further, I have determined the InsP6 hydrolysis pathways for several PTPLPs and present a novel IP specificity assay. With this assay, I identify that the two repeats of PhyAmm have divergent activities that clearly indicate a ’divide and conquer’ approach to maximize phosphoryl group removal from InsP6 and mixed IPs.

In order to understand the substrate specificity of protein tyrosine phosphatase-like myo-inositol phosphatases (PTPLPs), I have determined the structure of PhyA from Mitsuokella multacida (PhyAmm) and Selenomonas ruminantium (PhyAsr) in complex with multiple myo-inositol phosphates (IPs). These are the first atomic resolution structures of PTPLPs in complex with InsP5, InsP4, or InsP3 substrates, and represent four of the five known PTPLP:IP complex structures. Based on these structures, I have identified three structural features that determine the substrate specificity of PTPLPs. As part of this work, I demonstrate that the PhyAmm C-terminal repeat and PhyAsr bind substrates using conserved phosphoryl-binding sites. Further, I have determined the InsP6 hydrolysis pathways for several PTPLPs and present a novel IP specificity assay. With this assay, I identify that the two repeats of PhyAmm have divergent activities that clearly indicate a ’divide and conquer’ approach to maximize phosphoryl group removal from InsP6 and mixed IPs.

In order to understand the substrate specificity of protein tyrosine phosphatase-like myo-inositol phosphatases (PTPLPs), I have determined the structure of PhyA from Mitsuokella multacida (PhyAmm) and Selenomonas ruminantium (PhyAsr) in complex with multiple myo-inositol phosphates (IPs). These are the first atomic resolution structures of PTPLPs in complex with InsP5, InsP4, or InsP3 substrates, and represent four of the five known PTPLP:IP complex structures. Based on these structures, I have identified three structural features that determine the substrate specificity of PTPLPs. As part of this work, I demonstrate that the PhyAmm C-terminal repeat and PhyAsr bind substrates using conserved phosphoryl-binding sites. Further, I have determined the InsP6 hydrolysis pathways for several PTPLPs and present a novel IP specificity assay. With this assay, I identify that the two repeats of PhyAmm have divergent activities that clearly indicate a ’divide and conquer’ approach to maximize phosphoryl group removal from InsP6 and mixed IPs.

In order to understand the substrate specificity of protein tyrosine phosphatase-like myo-inositol phosphatases (PTPLPs), I have determined the structure of PhyA from Mitsuokella multacida (PhyAmm) and Selenomonas ruminantium (PhyAsr) in complex with multiple myo-inositol phosphates (IPs). These are the first atomic resolution structures of PTPLPs in complex with InsP5, InsP4, or InsP3 substrates, and represent four of the five known PTPLP:IP complex structures. Based on these structures, I have identified three structural features that determine the substrate specificity of PTPLPs. As part of this work, I demonstrate that the PhyAmm C-terminal repeat and PhyAsr bind substrates using conserved phosphoryl-binding sites. Further, I have determined the InsP6 hydrolysis pathways for several PTPLPs and present a novel IP specificity assay. With this assay, I identify that the two repeats of PhyAmm have divergent activities that clearly indicate a ’divide and conquer’ approach to maximize phosphoryl group removal from InsP6 and mixed IPs.

In order to understand the substrate specificity of protein tyrosine phosphatase-like myo-inositol phosphatases (PTPLPs), I have determined the structure of PhyA from Mitsuokella multacida (PhyAmm) and Selenomonas ruminantium (PhyAsr) in complex with multiple myo-inositol phosphates (IPs). These are the first atomic resolution structures of PTPLPs in complex with InsP5, InsP4, or InsP3 substrates, and represent four of the five known PTPLP:IP complex structures. Based on these structures, I have identified three structural features that determine the substrate specificity of PTPLPs. As part of this work, I demonstrate that the PhyAmm C-terminal repeat and PhyAsr bind substrates using conserved phosphoryl-binding sites. Further, I have determined the InsP6 hydrolysis pathways for several PTPLPs and present a novel IP specificity assay. With this assay, I identify that the two repeats of PhyAmm have divergent activities that clearly indicate a ’divide and conquer’ approach to maximize phosphoryl group removal from InsP6 and mixed IPs.

In order to understand the substrate specificity of protein tyrosine phosphatase-like myo-inositol phosphatases (PTPLPs), I have determined the structure of PhyA from Mitsuokella multacida (PhyAmm) and Selenomonas ruminantium (PhyAsr) in complex with multiple myo-inositol phosphates (IPs). These are the first atomic resolution structures of PTPLPs in complex with InsP5, InsP4, or InsP3 substrates, and represent four of the five known PTPLP:IP complex structures. Based on these structures, I have identified three structural features that determine the substrate specificity of PTPLPs. As part of this work, I demonstrate that the PhyAmm C-terminal repeat and PhyAsr bind substrates using conserved phosphoryl-binding sites. Further, I have determined the InsP6 hydrolysis pathways for several PTPLPs and present a novel IP specificity assay. With this assay, I identify that the two repeats of PhyAmm have divergent activities that clearly indicate a ’divide and conquer’ approach to maximize phosphoryl group removal from InsP6 and mixed IPs.

Aims: Investigation of intestinal bacterial groups involved in phytate degradation and the impact of diets with different phytate contents on phytase activity. Methods and Results: Faecal samples of adults on conventional (n = 8) or vegetarian (n = 8) diets and breastfed infants (n = 6) were used as an inoculum for modified media supplemented with phytate. Populations of Gram-positive anaerobes (GPA), lactic acid bacteria (LAB), Proteobacteria-Bacteroides (P-B), coliforms and anaerobes were studied. The PCR-DGGE analysis revealed a random distribution of DGGE profiles in the dendrograms of GPA, P-B and coliforms, and a partially diet-specific distribution in the DGGE dendrograms of LAB and anaerobes. The degradation of phytic acid (PA) was determined with HPLC method in supernatants of the cultures. Regardless of the diet, the Gram-positive anaerobes and LAB displayed the lowest ability to degrade phytate, whereas the coliforms and P-B cultures produced higher amounts of intermediate myo-inositol phosphates. Bacterial populations grown in a nonselective medium were the most effective ones in phytate degradation. It was the vegetarians' microbiota that particularly degraded up to 100% phytate to myo-inositol phosphate products lower than InsP3. Conclusions: A diet rich in phytate increases the potential of intestinal microbiota to degrade phytate. The co-operation of aerobic and anaerobic bacteria is essential for the complete phytate degradation. Significance and Impact of the Study: This study provides insights on the effect of diet on specific metabolic activity of human intestinal microbiota.

Microbial phytases represent a potential alternative way to produce myo-inositol phosphate isomers with therapeutic properties, whereas the chemical synthesis of these compounds is inefficient and costly. The aim of this work is to study the physiological role of histidine acid phytase in Pantoea sp 3.5.1 cells. Promoter region of the phytase gene was studied and potential binding sites for transcription factors RpoD15 and MetJ were identified by the methods of bioinformatic analysis. Genomic locus carrying the phytase gene was characterised and compared with the same genomic loci of other enterobacteria. It was found that the isolated and purified phytase from Pantoea sp. 3.5.1 refers to the Agp- group of histidine acid phytases and has dual physiological role in the bacterial cell. As glucose-1-phosphatase it is involved in glycolysis processes. The data obtained by stereospecifity analysis helped to identify that phytase from Pantoea sp. 3.5.1 is the enzyme that carries out phytate hydrolysis by the second path and forms D/L-myo-inositol-1,2,4,5,6-pentakisphosphate as the end product.

Microbial phytases represent a potential alternative way to produce myo-inositol phosphate isomers with therapeutic properties, whereas the chemical synthesis of these compounds is inefficient and costly. The aim of this work is to study the physiological role of histidine acid phytase in Pantoea sp 3.5.1 cells. Promoter region of the phytase gene was studied and potential binding sites for transcription factors RpoD15 and MetJ were identified by the methods of bioinformatic analysis. Genomic locus carrying the phytase gene was characterised and compared with the same genomic loci of other enterobacteria. It was found that the isolated and purified phytase from Pantoea sp. 3.5.1 refers to the Agp- group of histidine acid phytases and has dual physiological role in the bacterial cell. As glucose-1-phosphatase it is involved in glycolysis processes. The data obtained by stereospecifity analysis helped to identify that phytase from Pantoea sp. 3.5.1 is the enzyme that carries out phytate hydrolysis by the second path and forms D/L-myo-inositol-1,2,4,5,6-pentakisphosphate as the end product.