A novel phytase from Citrobacter gillenii: characterization and expression in Pichia pastoris (Komagataella pastoris)

The phyCg gene encoding a new phytase from C. gillenii was optimized, synthesized, cloned, and expressed in Pichia pastoris. Analysis of the amino acid sequence of the enzyme showed that it belongs to the histidine acid phosphatase family. The amino acid sequence of the PhyCg phytase has the highest homology (73.49%) with a phytase sequence from Citrobacter braakii. The main characteristics for the purified recombinant phytase were established. The optimum pH and temperature were 4.5 and 50°C, respectively. The specific activity of the enzyme was 1577 U/mg. The Michaelis constant (Km) and the maximum reaction rate (Vmax) for sodium phytate were 0,185 mM and 2185 U/mg, respectively. The enzyme showed the pH and trypsin stability and had a high activity over a wide pH range.

Heterologous Expression of Histidine Acid Phytase From Pantoea sp. 3.5.1 in Methylotrophic Yeast Pichia Pastoris

Background and Objective: The major storage form of phosphorus in plant-derived feed is presented by phytates and not digested by animals. Phytases are able to hydrolyze phytates and successfully used as feed additives. Nevertheless, nowadays, there is a constant search of new phytases and expression systems for better production of these enzymes. In this study, we describe cloning and expression of gene encoding histidine acid phytase from Pantoea sp. 3.5.1 using methylotrophic yeast Pichia pastoris as the host. Methods: The phytase gene was placed under the control of the methanol-inducible AOX1 promoter and expressed in P. pastoris. Experiments of small-scale phytase expression and activity assays were used to test recombinant colonies. Four different signal peptides were screened for better secretion of phytase by P. pastoris. After 36 h of methanol induction in shake flasks, the maximum extracellular phytase activity (3.2 U/ml) was observed in P. pastoris strain with integrated construct based on pPINK-HC vector and Kluyveromyces maxianus inulinase gene signal sequence. This phytase was isolated and purified using affinity chromatography. Results: Recombinant phytase was a glycosylated protein, had a molecular weight of around 90 kDa and showed maximum activity at pH 4.0 and at 50°C. Recombinant phytase had excellent thermal stability – it retained high residual activity (100% ± 2%) after 1 hour of heat treatment at 70°C. Conclusion: The enhanced thermostability of the recombinant phytase, its expression provided by strong inducible promotor and the effectively designed expression cassette, the simple purification procedure of the secreted enzyme, and the possibility of large-scale expression make the foundation for further production of this bacterial phytase in P. pastoris at an industrial scale.

BIOCHEMICAL CHARACTERIZATION OF RECOMBINANT PHYTASE ENZYME (phyK) FROM Klebsiella sp. ASR1 ENCAPSULATED WITH ALGINATE

Karakterisasi Biokimia Enzim Fitase Rekombinan (phyK) dari Klebsiella sp. ASR1 Yang Dienkapsulasi Dengan AlginatEnzim fitase melepas molekul fosfor pada atom C dari benzena Inositol fitat. Tetapi fitase memiliki kelemahan tidak mampu bertahan terhadap kondisi ekstrim dalam lambung nonruminansia. Solusi dalam penelitian ini yaitu fitase dienkapsulasi menggunakan alginat. Penelitian ini bertujuan mengkarakterisasi fitase setelah dienkapsulasi menggunakan alginate. Hasil penelitian ini yaitu fitase yang dienkapsulasi memiliki aktivitas tertinggi pada pH 6,0, sedangkan fitase tanpa enkapsulasi pada pH 5,0. Suhu optimum untuk aktivitas tertinggi fitase yang dienkapsulasi yaitu 70ºC, sedangkan fitase tanpa enkapsulasi 37ºC. Untuk perlakuan penambahan ion logam, aktivitas tertinggi fitase yang dienkapsulasi terjadi dengan penambahan 0,1 mM Fe2+ dan 1,0 mM Ca2+, sedangkan fitase tanpa enkapsulasi dengan penambahan 0,1 mM Fe2+. Berdasarkan hasil penelitian ini, fitase yang dienkapsulasi memiliki keunggulan lebih banyak dibandingkan dengan fitase tanpa enkapsulasi, karena mampu bertahan pada pH dan suhu tinggi, dan beberapa efek ion logam.Kata Kunci: alginat, asam fitat, enkapsulasi, fitase, fitase rekombinanABSTRACTPhytase enzymes release phosphorus molecules on the C atom from benzene inositol phytate. But phytase has the disadvantage of being unable to withstand extreme conditions in the non-ruminant stomach. The solution in this research was phytase encapsulated using alginate. This study aims to characterize phytase after being encapsulated using alginate. The results of this study were the encapsulated phytase had the highest activity at pH 6.0, while the unencapsulated phytase at pH 5.0. The optimum temperature for the highest activity of the encapsulated phytase was 70ºC, while the unencapsulated phytase 37ºC. For treatment of metal ion addition, the highest activity of the encapsulated phytase occurred with the addition of 0.1 mM Fe2+ and 1.0 mM Ca2+, while the unencapsulated phytase with the addition of 0.1 mM Fe2+. Based on the results of this study, the encapsulated phytase had more advantages compared to the unencapsulated phytase, as the former withstand high pH and temperature, and some metal ion effects.

Transgenic soybean expressing a thermostable phytase as substitution for feed additive phytase

Phytase is one of the most effective feed additives to increase the availability of phosphorus and minerals by catalyzing the hydrolysis of phytic acid. A modified appA gene (mappA) was transformed into soybean (Glycine max) under the control of a seed-specific promoter from common bean (Phaselous vulgaris). The soybean recombinant phytase showed optimal activity at pH 4.5 and 70 °C. A slight increase in enzyme activity occurred when the recombinant enzyme was pre-incubated with n-hexane. In addition, the phytase activity from our transgenic soybean does not reduce even after 2 hours of extraction with n-hexane at 55~65 °C. In conclusion, the oil extraction process using n-hexane does not inactivate the phytase expressed in the mAppA transgenic soybean, and the meal derived from the transgenic soybean processing can be used as feed supplement to livestock.

New Recombinant Phytase from Kosakonia sacchari: characteristic and biotechnological potential

A DNA sequence from Kosakonia sacchari that according to automated computer analysis is believed to correspond to a gene for histidine acid phytase has been selected from the GenBank database. The sequence was optimized for codon composition, synthesized, cloned and expressed in Pichia pastoris. Main characteristics of the purified recombinant enzyme were determined. It was established that the values of pH=4.5 and temperature of 50 °C are optimal for the phytase functioning. The values of specific activity, Michaelis constant (Km) and maximum reaction rate (Vmax) with phytate as a substrate were 1470 U/mg, 193 uM and 2167 umol/(min ∙ mg), respectively. It was shown that the enzyme was characterized by a wide range of working pH. Therefore, the properties of a new recombinant phytase allow us to consider it as a high-potential enzyme for agrobiotechnology. histidine acid phosphatases, Kosakonia sacchari phytase, Pichia pastoris The work was financially supported by the Ministry of Education and Science of Russian Federation (Unique Project Identifier RFMEFI57917X0145) and was carried out using the Multipurpose Scientific Installation of National Bio-resource Center «All-Russian Collection of Industrial Microorganisms», NRC «Kurchatov Institute» - GOSNIIGENETIKA.

Comparative Characteristics of Phytases from Citrobacter freundii and Yersinia intermedia Expressed in Ogataea polymorpha and Pichia pastoris Methylotrophic Yeasts

The genes for bacterial phytases from Citrobacter freundii and Yersinia intermedia were expressed for the first time in a thermotolarant yeast Ogataea polymorpha. A comparative analysis of the properties of recombinant phytases produced by Ogataea polymorpha and Pichia pastoris yeasts was carried out. It was shown that the stability, pH and temperature profiles of the enzyme activities are the same regardless of the host strain. It was proved that O. polymorpha yeast can be used to create producers of feed enzymes and to develop a technology for their cultivation at temperatures above 37 °C. The prospects of using the O. polymorpha yeast for these purposes were evaluated. Ogataea (Hansenula) polymorpha, Pichia pastoris, methylotrophic yeast, thermal tolerance, producer, recombinant phytase The work was financially supported by the Ministry of Science and Higher Education of RF (Project Unique Identifier RFMEFI57917X0145) using the Multipurpose Scientific Installation of All-Russian National Collection of Industrial Microorganisms National Bioresource Center, NRC «Kurchatov Institute»-GosNIIgenetika.