Molecular characterization, physicochemical properties, known and potential applications of phytases: An overview

Abstract

Phytases (myo-inositol hexakisphosphate phosphohydrolases) hydrolyze the phosphate ester bonds of phytate-releasing phosphate and lower myo-inositol phosphates and/or myo-inositol. Phytases, in general, are known to enhance phosphate and mineral uptake in monogastric animals such as poultry, swine, and fish, which cannot metabolize phytate besides reducing environmental pollution significantly. In this study, the molecular, biophysical, and biochemical properties of phytases are reviewed in detail. Alterations in the molecular and catalytic properties of phytases, upon expression in heterologous hosts, are discussed. Diverse applications of phytases as feed additives, as soil amendment, in aquaculture, development of transgenic organisms, and as nutraceuticals in the human diet also are dealt with. Furthermore, phytases are envisaged to serve as potential enzymes that can produce versatile lower myo-inositol phosphates of pharmaceutical importance. Development of phytases with improved attributes is an important area being explored through genetic and protein engineering approaches, as no known phytase can fulfill all the properties of an ideal feed additive.

Nutritionally Enhanced Staple Food Crops

“…Phytases, known to enhance phosphate and mineral uptake in monogastric animals, catalyze the hydrolysis of phytate to myo-inositol pentakisphosphate (IP 5 ) or to less phosphorylated myo-inositol phosphates IP3. The phytases isolated from plant, microorganism, and animal tissues are broadly classified into three types, 3-phytases, 6-phytases, and 5-phytases, depending on the initiation site of dephosphorylation (Rao et al 2009). A thermotolerant phytase gene from Aspergillus has been used to alter phytic acid in maize, rice, and soybean (Table 3.10 ).…”

Protein Engineering Methods and Applications

“…Screening organic solvent-tolerant bacteria or extremophiles has been preferred to isolate and improve naturally solvent-stable enzymes (Gupta & Khare, 2009;Doukyu & Ogino, 2010). Other protein engineering examples with industrially and/or pharmacologically important enzymes include studies on cholesterol oxidase (Pollegioni et al, 2009), cyclodextrin glucanotransferases (Leemhuis et al, 2010), human butyrylcholinesterase (Masson et al, 2009), microbial glucoamylases (Kumar & Satyanarayana, 2009), lipases of different origins (Akoh et al, 2004;Verma et al, 2008;Kurtovic et al, 2009), phospholipases (Song et al, 2005;De Maria et al, 2007;Simockova & Griac, 2009) and phytases (Rao et al, 2009). Studies on extremozymes, enzymes isolated from extremophilic species, revealed their different structural and functional characteristics which could be exploited for biotechnological applications and improved further by protein engineering (Bjarnason et al, 1993;Hough & Danson, 1999;Georlette et al, 2004).…”

“…Food industry applications (James & Simpson, 1996), (Kirk et al, 2002), (Akoh et al, 2008) Detergent industry applications (proteases) (Gupta et al, 2002) Environmental applications (Wiseman, 1993), (Cirino & Arnold, 2002), (Le Borgne & Quintero, 2003), (Ayala et al, 2008), (Cao et al, 2009) Medical applications (Buckel, 1996), (Filpula & McGuire, 1999), (Paques & Duchateau, 2007), (Nuttall & Walsh, 2008), (Liu et al, 2009), (Lam et al, 2003), (Zafir-Lavie et al, 2007), (Vazquez et al, 2009), (Olafsen & Wu, 2010) Biopolymer production applications (Chow et al, 2008), (Rehm, 2010), (Banta et al, 2010) Nanobiotechnology applications (Hamada et al, 2004), (Sarikaya et al, 2003) Applications with redox proteins and enzymes (Saab-Rincon & Valderrama, 2009), (Kumar, 2010) Applications with various industrially important enzymes (Martinkova & Kren, 2010), (Clapes et al, 2010), (Jordan & Wagschal, 2010), (Rao et al, 2009), (Marcaida et al, 2010).…”

Strategies for Iron Biofortification of Crop Plants

“…Such enzymes are isolated from a multitude of different microorganisms, and heat-stability besides enzyme activity are important criteria to consider in the food processing procedure (Bohn et al, 2008;Rao et al, 2009). …”