Characteristics of Recombinant Phytase (rSt-Phy) of the Thermophilic mold Sporotrichum thermophile and its applicability in dephytinizing foods

Abstract

Sporotrichum thermophile produces very low titres of phytase (St-Phy) extracellularly, which is acidstable, thermostable, and protease insensitive with broad substrate specificity, and therefore, the gene encoding phytase (St-Phy) has been cloned and expressed in E. coli. The purified recombinant phytase (rSt-Phy) has the molecular mass of 55 kDa with Km and Vmax (calcium phytate), kcat and kcat/Km of 0.143 mM, 185.05 nmoles mg(-1) s(-1), 5.1 × 10(3) s(-1), and 3.5 × 10(7) M(-1) s(-1), respectively. Mg(2+) and Ba(2+) display slight stimulatory effect on the enzyme, while it is inhibited by other ions to a varied extent. The enzyme is also inhibited by chaotropic agents (guanidinium hydrochloride, potassium iodide, and urea), Woodward's reagent K, and 2,3-butanedione but resistant to both pepsin and trypsin. The rSt-Phy is useful in dephytinization of tandoori and naan (unleavened flat Indian breads), and bread, liberating soluble inorganic phosphate that mitigates anti-nutrient effects of phytic acid.

Bioprocess for Production, Characteristics, and Biotechnological Applications of Fungal Phytases

“…Therefore, the recombinant phytase values obtained from their studies suggested that the additional protein stability would be required to withstand the elevated temperatures involved in soybean growth processing. In addition, the thermophilic mold Sporotrichum thermophile has been investigated in terms of the cloning and expression of phytase heterologously in bacteria (e.g., Escherichia coli) or yeast (e.g., Pichia pastoris) (Ranjan et al, 2015;Singh et al, 2018). The recombinant phytase (rSt-Phy) of the thermophilic mold S. thermophile (St-Phy) had been cloned and expressed in E. coli by Ranjan et al (2015).…”

“…In addition, the thermophilic mold Sporotrichum thermophile has been investigated in terms of the cloning and expression of phytase heterologously in bacteria (e.g., Escherichia coli) or yeast (e.g., Pichia pastoris) (Ranjan et al, 2015;Singh et al, 2018). The recombinant phytase (rSt-Phy) of the thermophilic mold S. thermophile (St-Phy) had been cloned and expressed in E. coli by Ranjan et al (2015). They reported that rSt-Phy was produced in LB medium containing glycerol and glucose with a specific activity of 8000 U/mg total intracellular protein.…”