Kinetics of phytate hydrolysis by Aspergillus niger phytase and correlation between the amount of released phosphate and creation of lower myo-inositol phosphates were investigated. Phytase was able to hydrolyze myo-inositol hexakis-, pentakis-, tetrakis-, and trisphosphates. Finally, about 56% of total phosphate were released and myo-inositol bisphosphate was detected as the end-product.

• MeSH
• Aspergillus niger enzymologie   MeSH
• fosfatasy metabolismus   MeSH
• hmotnostní spektrometrie MeSH
• inositolfosfáty analýza   metabolismus   MeSH
• kinetika MeSH
• kyselina fytová metabolismus   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 3-phytase MeSH Prohlížeč
• fosfatasy MeSH
• inositolfosfáty MeSH
• kyselina fytová MeSH

Eighty-three isolates from different soil samples exhibited the potential for producing active extracellular phytase. The most active fungal isolate with phytase activity was identified as Penicillium simplicissimum. In shaking culture with enrichment medium, the highest extracellular phytase activity of the producing strain was 3.8 U/mL. The crude enzyme filtrate was purified to homogeneity using ultrafiltration. IEC and gel filtration chromatography. The molar mass of the purified enzyme was estimated to be 65 kDa on SDS-PAGE. The saccharide identification with periodic acid-Schiff reagent (PAS) and activity recognition by 1-naphthyl phosphate was all positive. The isoelectric point of the enzyme, as deduced by isoelectric focusing, was pH 5.8, the optimum pH and temperature being pH 4.0 and 55 degrees C, respectively. The purified enzyme revealed broad substrate specificity and was strongly inhibited by Fe2+, Fe3+ and Zn2+; however, no inhibition was found by EDTA and PMSF. Phytase activity was inhibited when 2 mmol/L of dodecasodium phytate was added and the Km for it was determined to be 813 mmol/L.

• MeSH
• 6-fytasa chemie   izolace a purifikace   metabolismus   MeSH
• chromatografie iontoměničová MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• gelová chromatografie MeSH
• ionty farmakologie   MeSH
• koncentrace vodíkových iontů MeSH
• kovy farmakologie   MeSH
• molekulová hmotnost MeSH
• Penicillium enzymologie   MeSH
• půdní mikrobiologie MeSH
• substrátová specifita MeSH
• teplota MeSH
• ultrafiltrace MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 6-fytasa MeSH
• ionty MeSH
• kovy MeSH

This review deals with phytase (myo-inositol hexakisphosphate phosphohydrolase) and covers microbiological sources, phytase occurrence in plants and animals, its purification, physico-chemical and molecular properties. Protein engineering of phytase and potential enzyme applications are discussed.

• MeSH
• 6-fytasa * genetika   izolace a purifikace   metabolismus   MeSH
• Bacteria enzymologie   MeSH
• fyziologie výživy zvířat MeSH
• houby enzymologie   MeSH
• lidé MeSH
• potravinářský průmysl MeSH
• rostliny enzymologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• 6-fytasa * MeSH

The extracellular activity of Aspergillus niger phytase at the end of the growth phase was 132 nkat/mL in a laboratory bioreactor. The purified enzyme has molar mass approximately 100 kDa, pH optimum at 5.0, temperature optimum at 55 degrees C and high pH and temperature stability. The Km for dodecasodium phytate, calcium phytate and 4-nitrophenyl phosphate are 0.44, 0.45 and 1.38 mmol/L, respectively. The enzyme is noncompetively inhibited by inorganic monophosphate (Ki = 2.85 mmol/L) and by Cu2+, Zn2+, Hg2+, Sn2+, Cd2+ ions and strongly by F- ones; it is activated by Ca2+, Mg2+ and Mn2+ ions. The substrate specificity of phytase is broad with the highest affinity to calcium phytate.

• MeSH
• 6-fytasa antagonisté a inhibitory   izolace a purifikace   metabolismus   MeSH
• Aspergillus niger enzymologie   MeSH
• fungální proteiny antagonisté a inhibitory   izolace a purifikace   metabolismus   MeSH
• inhibitory enzymů farmakologie   MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• kyselina fytová metabolismus   MeSH
• molekulová hmotnost MeSH
• substrátová specifita MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• 6-fytasa MeSH
• fungální proteiny MeSH
• inhibitory enzymů MeSH
• kyselina fytová MeSH