02336nas a2200253   4500008004100000022001400041245014600055210006900201260009400270300001400364490000600378520134000384653002401724653002201748653001201770653002401782653002801806653002701834100002401861700001601885700002501901700002601926856013001952       2008                        eng d  a1684-531500aInfluence of pretreatment of agriculture residues on phytase production by aspergillus niger NCIM 563 under submerged fermentation conditions0 aInfluence of pretreatment of agriculture residues on phytase pro  aP O BOX 5170-00200 NAIROBI, VICTORIA ISLAND, LAGOS 73023, NIGERIAbACADEMIC JOURNALScAPR  a1101-11060 v73 a<p>The extracellular phytase production by Aspergillus niger NCIM 563 was evaluated in medium containing various agriculture residues under submerged fermentation conditions. Phytase production was affected by inorganic phosphate content of agriculture residues which ranged from 2.8 to 8 mg/g. The agriculture residues containing less than 4 mg/g inorganic phosphate supported phytase production with maximum activity of 68 IU/ml in medium containing 1% rice bran on 11(th) day of fermentation. Addition of glucose up to 5% in fermentation medium containing 1% rice bran, enhanced phytase production. Pretreatment of agriculture residues with water to remove excess inorganic phosphate has significantly enhanced the phytase activity in case of de-oiled rice bran, wheat bran, peanut cake (low and high oil) and coconut cake. Maximum increase of 20.3 times in phytase activity was observed in case of wheat bran as compared to de-oiled rice bran, coconut cake, peanut cake high and low oil in which the increase in phytase activity was 6.85, 6.1, 5.3 and 3.0 times, respectively. Maximum phytase activity of 68 IU/ml was produced on the 11(th) day of fermentation compared to earlier reported 41.47 IU/ml phytase activity on the 15(th) day of submerged fermentation using 5% dextrin and 2.5% glucose, thus increasing productivity.</p>10aAgriculture residue10aAspergillus niger10aPhytase10aphytate degradation10aPoultry feed supplement10aSubmerged fermentation1 aBhavsar, Kavita, P.1 aShah, Parin1 aSoni, Sarvesh, Kumar1 aKhire, Jayant, Malhar  uhttp://library.ncl.res.in/content/influence-pretreatment-agriculture-residues-phytase-production-aspergillus-niger-ncim-563-003036nas a2200241   4500008004100000022001400041245015800055210006900213260005700282300001300339490000700352520210200359653002802461653003502489653001302524653003002537653002002567100001702587700001802604700002402622700002602646856012202672       2015                        eng d  a1610-294000aInsights into the unfolding pathway and identification of thermally sensitive regions of phytase from aspergillus niger by molecular dynamics simulations0 aInsights into the unfolding pathway and identification of therma  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcJUN  aUNSP 1630 v213 a<p>Thermal stability is of great importance in the application of commercial phytases. Phytase A (PhyA) is a monomeric protein comprising twelve alpha-helices and ten beta-sheets. Comparative molecular dynamics (MD) simulations (at 310, 350, 400, and 500 K) revealed that the thermal stability of PhyA from Aspergillus niger (A. niger) is associated with its conformational rigidity. The most thermally sensitive regions were identified as loops 8 (residues 83-106), 10 (161174), 14 (224-230), 17 (306-331), and 24 (442-444), which are present on the surface of the protein. It was observed that solvent-exposed loops denature before or show higher flexibility than buried residues. We observed that PhyA begins to unfold at loops 8 and 14, which further extends to loop 24 at the C-terminus. The intense movement of loop 8 causes the helix H2 and beta-sheet B3 to fluctuate at high temperature. The high flexibility of the H2, H10, and H12 helices at high temperature resulted in complete denaturation. The high mobility of loop 14 easily transfers to the adjacent helices H7, H8, and H9, which fluctuate and partially unfold at high temperature (500 K). It was also observed that the salt bridges Asp110-Lys149, Asp205-Lys277, Asp335-Arg136, Asp416-Arg420, and Glu387-Arg400 are important influences on the structural stability but not the thermostability, as the lengths of these salt bridges did not increase with rising temperature. The salt bridges Glu125-Arg163, Asp299-Arg136, Asp266-Arg219, Asp339-Lys278, Asp335-Arg136, and Asp424-Arg428 are all important for thermostability, as the lengths of these bridges increased dramatically with increasing temperature. Here, for the first time, we have computationally identified the thermolabile regions of PhyA, and this information could be used to engineer novel thermostable phytases. Numerous homologous phytases of fungal as well as bacterial origin are known, and these homologs show high sequence similarity. Our findings could prove useful in attempts to increase the thermostability of homologous phytases via protein engineering.</p>10aConformational dynamics10aMolecular dynamics simulations10aPhytaseA10aStructurally weak regions10aThermostability1 aKumar, Kapil1 aPatel, Krunal1 aAgrawal, Dinesh, C.1 aKhire, Jayant, Malhar  uhttp://library.ncl.res.in/content/insights-unfolding-pathway-and-identification-thermally-sensitive-regions-phytase-1