@article { ISI:000313651700018,
	title = {Combinatorial approach of statistical optimization and mutagenesis for improved production of acidic phytase by Aspergillus niger NCIM 563 under submerged fermentation condition},
	journal = {Applied Microbiology and Biotechnology},
	volume = {97},
	number = {2},
	year = {2013},
	month = {JAN},
	pages = {673-679},
	publisher = {SPRINGER},
	address = {233 SPRING ST, NEW YORK, NY 10013 USA},
	abstract = {<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>},
	keywords = {Animal feed, Aspergillus niger, Mutagenesis, Phytase, Statistical optimization},
	issn = {0175-7598},
	doi = {10.1007/s00253-012-3965-8},
	author = {Bhavsar, Kavita P. and Gujar, P. and Shah, P. and Kumar, V. Ravi and Khire, Jayant Malhar}
}
@article { ISI:000338640200014,
	title = {Current research and future perspectives of phytase bioprocessing},
	journal = {RSC Advances},
	volume = {4},
	number = {51},
	year = {2014},
	month = {MAY},
	pages = {26677-26691},
	publisher = {ROYAL SOC CHEMISTRY},
	address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND},
	abstract = {<p>Phosphorus is one of nature{\textquoteright}s paradoxes as it is life{\textquoteright}s bottleneck for subsistence on earth but at same time is detrimental in surplus quantities in an aquatic environment. Phosphorus cannot be manufactured, though fortunately it can be recovered and reused. The only way to avert a supply crisis is to implement the {\textquoteleft}{\textquoteleft}3R{\textquoteright}s{\textquoteright}{\textquoteright} of sustainability, {\textquoteleft}{\textquoteleft}Reduce, Reuse and Recycle.{\textquoteright}{\textquoteright} Phytase is likely to play a critical role in the dephosphorylation of antinutritional and indigestible phytate, a phosphorus locking molecule, to digestible phosphorus, calcium and other mineral nutrients in the coming years. Hence, efforts are required to produce cost effective phytase with fast upstream and economic downstream processing because the current available process is expensive and time consuming. This review summarizes the present state of methods studied for phytase bioprocessing. Production, extraction and purification incur a large cost in product development. In addition, the process has several limitations such as dilute concentration of enzyme, extensive downstream procedures and treatment of generated effluents. However, these methods are currently employed due to lack of alternative methods. Thus, there is a clear need for an efficient, scalable and economical process for phytase production and bioseparation, and improvements are especially required with regard to yield, purity, and energy consumption. Perspectives for an improved bioprocess development for phytase are discussed based on our own experience and recent studies. It is argued that the optimization of production techniques, strain improvement and liquid-liquid extraction deserves more attention in the future.</p>},
	issn = {2046-2069},
	doi = {10.1039/c4ra03445g},
	author = {Bhavsar, Kavita P. and Khire, Jayant Malhar}
}
