ArticleApplied and environmental microbiology2006
Shifting the pH profile of Aspergillus niger PhyA phytase to match the stomach pH enhances its effectiveness as an animal feed additive.
Article in Applied and environmental microbiology, 2006. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 14 papers.
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14 citing papers in PubMed, 113 citations in OpenAlex.
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- Article
- Bioprocessing of Agricultural Residues as Substrates and Optimal Conditions for Phytase Production of Chestnut Mushroom,Journal of fungi (Basel, Switzerland) · 2020Article
- Computational design of enhanced detoxification activity of a zearalenone lactonase fromRSC advances · 2019Article
- Cloning, expression, and characterization of a porcine pancreatic α-amylase inAnimal nutrition (Zhongguo xu mu shou yi xue hui) · 2018Article
- Strain improvement of Pichia kudriavzevii TY13 for raised phytase production and reduced phosphate repression.Microbial biotechnology · 2017Article
- Sequence homolog-based molecular engineering for shifting the enzymatic pH optimum.Synthetic and systems biotechnology · 2016Article
- Development of phytase-expressing chlamydomonas reinhardtii for monogastric animal nutrition.BMC biotechnology · 2016Article
- Partial optimization of the 5-terminal codon increased a recombination porcine pancreatic lipase (opPPL) expression in Pichia pastoris.PloS one · 2014Article
- Influence of the Environment on the Morphological and Biochemical Characteristics of Different Aspergillus niger Wild Type Strains.Indian journal of microbiology · 2013Article
- Semi-rational site-directed mutagenesis of phyI1s from Aspergillus niger 113 at two residue to improve its phytase activity.Molecular biology reports · 2011Article
- Expression, purification and characterization of a phyA(m)-phyCs fusion phytase.Journal of Zhejiang University. Science. B · 2008Article
- Redesigning protein pKa values.Protein science : a publication of the Protein Society · 2007Article
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11 authors at 4 institutions in 1 country.
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No grant is acknowledged in the PubMed record.
Abstract
Environmental pollution by phosphorus from animal waste is a major problem in agriculture because simple-stomached animals, such as swine, poultry, and fish, cannot digest phosphorus (as phytate) present in plant feeds. To alleviate this problem, a phytase from Aspergillus niger PhyA is widely used as a feed additive to hydrolyze phytate-phosphorus. However, it has the lowest relative activity at the pH of the stomach (3.5), where the hydrolysis occurs. Our objective was to shift the pH optima of PhyA to match the stomach condition by substituting amino acids in the substrate-binding site with different charges and polarities. Based on the crystal structure of PhyA, we prepared 21 single or multiple mutants at Q50, K91, K94, E228, D262, K300, and K301 and expressed them in Pichia pastoris yeast. The wild-type (WT) PhyA showed the unique bihump, two-pH-optima profile, whereas 17 mutants lost one pH optimum or shifted the pH optimum from pH 5.5 to the more acidic side. The mutant E228K exhibited the best overall changes, with a shift of pH optimum to 3.8 and 266% greater (P < 0.05) hydrolysis of soy phytate at pH 3.5 than the WT enzyme. The improved efficacy of the enzyme was confirmed in an animal feed trial and was characterized by biochemical analysis of the purified mutant enzymes. In conclusion, it is feasible to improve the function of PhyA phytase under stomach pH conditions by rational protein engineering.
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