02417nas a2200229 4500008004100000022001400041245012600055210006900181260005700250300001400307490000700321520159900328653002201927653001201949653001201961653001701973653001701990100001702007700001502024700002602039856012202065 2010 eng d a0959-399300aPurification and characterization of two distinct acidic phytases with broad pH stability from aspergillus niger NCIM 5630 aPurification and characterization of two distinct acidic phytase a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcNOV a2009-20180 v263 a
Aspergillus niger NCIM 563 produced two different extracellular phytases (Phy I and Phy II) under submerged fermentation conditions at 30A degrees C in medium containing dextrin-glucose-sodium nitrate-salts. Both the enzymes were purified to homogeneity using Rotavapor concentration, Phenyl-Sepharose column chromatography and Sephacryl S-200 gel filtration. The molecular mass of Phy I and II as determined by SDS-PAGE and gel filtration were 66, 264, 150 and 148 kDa respectively, indicating that Phy I consists of four identical subunits and Phy II is a monomer. The pI values of Phy I and II were 3.55 and 3.91, respectively. Phy I was highly acidic with optimum pH of 2.5 and was stable over a broad pH range (1.5-9.0) while Phy II showed a pH optimum of 5.0 with stability in the range of pH 3.5-9.0. Phy I exhibited very broad substrate specificity while Phy II was more specific for sodium phytate. Similarly Phy II was strongly inhibited by Ag(+), Hg(2+) (1 mM) metal ions and Phy I was partially inhibited. Peptide analysis by Mass Spectrometry (MS) MALDI-TOF also indicated that both the proteins were totally different. The K (m) for Phy I and II for sodium phytate was 2.01 and 0.145 mM while V (max) was 5,018 and 1,671 mu mol min(-1) mg(-1), respectively. The N-terminal amino acid sequences of Phy I and Phy II were FSYGAAIPQQ and GVDERFPYTG, respectively. Phy II showed no homology with Phy I and any other known phytases from the literature suggesting its unique nature. This, according to us, is the first report of two distinct novel phytases from Aspergillus niger.
10aAspergillus niger10aPhytase10aPhytate10aPoultry feed10aPurification1 aSoni, S., K.1 aMagdum, A.1 aKhire, Jayant, Malhar uhttp://library.ncl.res.in/content/purification-and-characterization-two-distinct-acidic-phytases-broad-ph-stability-0