Thermally stable and acidic pH tolerant mutant phytases with high catalytic efficiency from Yersinia intermedia for potential application in feed industries

• Published in: Environmental science and pollution research international Vol. 29; no. 22; pp. 33713 - 33724
• Main Authors: Abbasi Kheirabadi, Marjan, Saffar, Behnaz, Hemmati, Roohullah, Mortazavi, Mojtaba
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-05-2022; Springer Nature B.V
• Subjects: 6-Phytase - chemistry; Affinity chromatography; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bioavailability; E coli; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Enzyme Stability; Enzymes; Escherichia coli - metabolism; Feed industry; Hydrogen-Ion Concentration; Minerals; Mutants; Nickel; pH effects; Phytase; Phytic acid; Research Article; Site-directed mutagenesis; Soil pollution; Soil water; Spectroscopy; Thermal stability; Waste Water Technology; Water Management; Water pollution; Water Pollution Control; Yersinia - chemistry; Yersinia intermedia; Feed industries; Mutagenesis; Environmental pollution; Protein purification; Phytic acid; Thermal stability
• DOI: 10.1007/s11356-022-18578-4
• EISSN: 1614-7499
• ISSN: 0944-1344

Heat- and pH-stable phytase efficiently hydrolyzes phytic acid. In this research, heat- and pH-stable mutant phytases, T
83
R, L
287
R, and T
83
R/L
287
R were generated by site-directed mutagenesis from
Yersinia intermedia
. After the induction and expression of recombinant wild-type and mutant phytases in
E. coli
BL21, the enzymes were purified using nickel sepharose affinity chromatography, and characterized kinetically and thermodynamically using spectroscopy methods. The mutants showed optimum activity at pH 5.15 and 55–61
°
C. The catalytic efficiencies of T
83
R, L
287
R, T
83
R/L
287
R, and wild-type phytases were calculated to be 2941, 29346, 4906, and 6917 mmol/L
−1
s
−1
, respectively. Moreover, after the incubation of T
83
R, L
287
R, wild-type, and T
83
R/ L
287
R phytases at 100
°
C for 1 h, the enzymes retained 22, 5, 4, and 2% of their initial activities, respectively. In addition, T
83
R, T
83
R/L
287
R, L
287
R, and wild-type phytases retained 82, 44, 16 as well as 11% of their initial activities after 1 h at pH 5.15, respectively. Among these mutants, T
83
R mutant showed 18% increase in thermal stability, 71% increase in pH stability, and +0.103 KJ/mole increase in ΔΔG, while the catalytic efficiency and ΔΔG value of L
287
R mutant increased by 4 times and +0.0903 KJ/mole, respectively. Thus, the mutants have the potential to be used in feed industries to increase the bioavailability of minerals while decreasing soil and water pollution.