Aspergillus phytase

As discussed above, wheat has been used only rarely for molecular farming. Thus far, the only example of a pharmaceutical protein produced in wheat is a single chain Fv antibody, which was expressed using the Ubil promoter and achieved a maximum expression level of 1.5 pg g 1 dry weight [77]. Transgenic wheat producing Aspergillus phytase has also been reported [78]. 

Richardson, A.E., Hadobas, P.A. and Hayes, J.E. (2001) Extracellular secretion of Aspergillus phytase from Arabidopsis roots enables plants to obtain phosphorus from phytate. Plant Journal 25, 1-10. 

RAPP c, LANTZSCH H J, DROCHNER w (2001) Hydrolysis of ph)dic acid hy intrinsic plant and supplemented microbial phytase Aspergillus niger) in the stomach and small intestine of minipigs fitted with re-entrant cannnlas. 3. Hydrolysis of ph)dic acid (1P6) and occurrence of hydrolysis products (1P5,1P4, 1P3 and 1P2). JAnim Physiol Anim Nutr (Berl). 85 420-30. 

In the multi-enzyme system described by Sheldon et al. [15], the key point is the use of the phosphatase phytase from Aspergillus ficuum, which is a cheap and readily available industrial enzyme. Phytase is active at acid pH and becomes inactive at neutral pH. Thus, the pH can be used to switch on/off the activities of the various enzymes, allowing us to carry out the four-enzyme cascade in one pot. 

Figure 6.9 Structure of phytase from Aspergillus fcum (Kostrewa, 1997).

Wheat Endosperm-specific phytase expression Seed Aspergillus fumigatus PhyA (40)... 

Phytase Aspergillus sp Mashing Releasing of phosphate from phytic acid in animal feed... 

Phytase (Aspergillus niger var.) Produced as an off white to brown powder or as a tan to dark brown liquid by controlled fermentation using Aspergillus niger var. Soluble in water, but practically insoluble in alcohol, in chloroform, and in ether. Major active principles (1) 3-phytase and (2) acid phosphatase. Typical applications used in the production of soy protein isolate and in the removal of phytic acid from plant materials. 

Phytase phosphatase Aspergillus niger var. (1) myo-inositol- hexakisphosphate-3- phosphohydrolase (2) orthophosphoric-mono ester phosphohydrolase 3.1.3.8 3.1.3.2... 

Phytase (Aspergillus niger var.), 20 Protease (Aspergillus niger var.), 20... 

Lipase (Rhizomucor (Mucorj miehei), 132, 787, (S3)20 Phytase (Aspergillus niger vat.), 132,... 

Immobilized phytase (from Aspergillus ficuum) has been applied in a similar manner to determine phosphate release from waters (McKelvie et al, 1995), but attempts to immobilize phosphodiesterase alone or co-immobilized with alkaline phosphatase proved unsuccessful because of loss of phosphodiesterase activity. Alkaline phosphatase, phytase and phosphodiesterase are relatively non-specific enzymes, and their use in applications such as those described above provides information on the broad functional classes of organic phosphorus compounds present. 

The lowest and the highest values for myo-inositol hexakisphosphate hydrolysis were reported in phytases of Aspergillus ficuum (pH 5.3, 0.01 mM) and in that of germinated Phaseolus aureus (0.65 mM), respectively. The highest values reported were of wheat bran phytase towards myoinositol tetrakis- and trisphosphate (5 mM see Nayini and Markakis, 1986). K and K, values for the enzymatic hydrolysis of myoinositol hexakisphosphate by different Bacillus spp. were determined to be approximately 0.44 mM and 18.6/s, respectively. The affinity of myo-inositol pentakisphosphate for the phytase enzymes and their maximal rates of hydrolysis were lower (K = 0.50-0.76 mM 7.4-16/s) than that of myo-inositol hexakisphosphate (Greiner et al., 2002). 

Wyss, M., Pasamontes, L., Remy, R., Kohler, J., Kusznir, E., Cadient, M., Muller, F. and van Loon, A.P.C.M. (1998) Comparison of the thermostability properties of three acid phosphatases from molds Aspergillus fumigatus phytase, A. n/ger phytase, and A. niger pH 2.5 acid phosphatase. Applied and Environmental Microbiology 54, 4446 451. 

Aspergillus oryzae [26] hemiceiiulase, pectinase, cellulase, catalase, phytase, protease, lipase, glucose oxidase a-amyiase, cellulase, glucoamylase, hemiceiiulase. 

Parmar A, Kumar H, Marwaha S et al. (2000) Advances in enzymatic transformation of penidllins to 6-aminopenidllanic add (6-APA). Biotechnol Adv 18 289—301 Pasamontes L, Haiker M, Wyss M et ak (1997) Gene cloning, purification, and characterization of a heat-stable phytase from the fungus Aspergillus fumigatus. Appl Einviron Microbiol 63(5) 1696-1700... 

Since vanadium chloroperoxidase from Curvularia inaequalis is structurally closely related to acid phosphatases and transition metal oxoanions are potent inhibitors of the related phytases, (Figure 10.8) [35,36], Sheldon and coworkers investigated the peroxidase activity of phytase from Aspergillus ficuum in the presence of sodium orthovanadate Na3V04 [37-39]. Oxidation of thioanisole with H2O2 proceeded to produce the sulfoxide in quantitative yield in the presence of [VO4]-phytase. The reaction rate showed saturation kinetics with respect to the vanadate concentration, indicating a maximum rate of 120pmol/h (TOF = 11 min ) and a dissociation constant for the vanadate ion of 15.4 pM. 

Phytase Aspergillus sp., Aspergillusficuum, Penicilliumfuniculosum, Bacillus sp., Pseudomonas, Xanthomonas oryzae... 

Jongbloed AW, Mroz Z, Kemme PA (1992) The effect of supplementary Aspergillus iger phytase in diets for pigs on concentration and apparent digestibility of dry matter, total phosphorus and phytic acid in different sections of the alimentary tract. J Anim Sci 70 1168... 

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