02605nas a2200253   4500008004100000022001400041245018200055210006900237260005700306300001200363490000700375520164900382653001602031653002202047653001602069653001202085653002902097100002402126700001402150700001302164700001602177700002602193856013202219       2013                        eng d  a0175-759800aCombinatorial approach of statistical optimization and mutagenesis for improved production of acidic phytase by Aspergillus niger NCIM 563 under submerged fermentation condition0 aCombinatorial approach of statistical optimization and mutagenes  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcJAN  a673-6790 v973 a<p>Combination of statistical optimization and mutagenesis to isolate hypersecretory strains is studied to maximize phytase production from Aspergillus niger NCIM 563 under submerged fermentation. The overall results obtained show a remarkable 5.98-fold improvement in phytase production rates when compared to that using basal medium. Optimization of culture conditions from parent strain is studied first by the Plackett-Burman technique to evaluate the effects of 11 variables for phytase production. The results showed that glucose, MgSO4, KCl, incubation period, and MnSO4 are the most significant variables affecting enzyme production. Further optimization in these variables, using a central composite design technique, resulted in 3.74-fold increase in the yield of phytase production to 254,500 U/l when compared with the activity observed with basal media (68,000 U/l) in shake flask. Our experiments show that the phytase from A. niger NCIM 563 exhibits desirable activity in simulated gastric fluid conditions with low pH and also improved thermostability when compared to commercial phytase. The improved yield demonstrates the potential applicability of phytase enzyme as a source of phytase supplement for phosphorus nutrition and environmental protection in animal feed industry. Physical and chemical mutagenesis experiments were carried out in parallel to isolate hypersecretory mutants that could possibly further enhance the enzyme production. Using optimized media conditions of the parent strain, our results show that mutant strain A. niger NCIM 1359 increased the phytase activity by another 1.6-fold to 407,200 U/l.</p>10aAnimal feed10aAspergillus niger10aMutagenesis10aPhytase10aStatistical optimization1 aBhavsar, Kavita, P.1 aGujar, P.1 aShah, P.1 aKumar, Ravi1 aKhire, Jayant, Malhar  uhttps://library.ncl.res.in/content/combinatorial-approach-statistical-optimization-and-mutagenesis-improved-production-acidic-0