Open AccessStrain improvement of Pichia kudriavzevii TY13 for raised phytase production and reduced phosphate repression
Author(s) -
Qvirist Linnea,
Vorontsov Egor,
Veide Vilg Jenny,
Andlid Thomas
Publication year - 2017
Publication title -
microbial biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.287
H-Index - 74
ISSN - 1751-7915
DOI - 10.1111/1751-7915.12427
Subject(s) - phytase , food science , strain (injury) , phosphate , bioavailability , chemistry , monogastric , biochemistry , fermentation , phytic acid , biology , microbiology and biotechnology , enzyme , nutrient , bioinformatics , organic chemistry , plant nutrition , anatomy
Summary In this work, we present the development and characterization of a strain of Pichia kudriavzevii ( TY 1322), with highly improved phytate‐degrading capacity. The mutant strain TY 1322 shows a biomass‐specific phytate degradation of 1.26 mmol g −1 h −1 after 8 h of cultivation in a high‐phosphate medium, which is about 8 times higher compared with the wild‐type strain. Strain TY 1322 was able to grow at low pH (pH 2), at high temperature (46°C) and in the presence of ox bile (2% w/v), indicating this strain's ability to survive passage through the gastrointestinal tract. The purified phytase showed two pH optima, at pH 3.5 and 5.5, and one temperature optimum at 55°C. The lower pH optimum of 3.5 matches the reported pH of the pig stomach, meaning that TY 1322 and/or its phytase is highly suitable for use in feed production. Furthermore, P. kudriavzevii TY 1322 tolerates ethanol up to 6% (v/v) and shows high osmotic stress tolerance. Owing to the phenotypic characteristics and non‐genetically modified organisms nature of TY 1322, this strain show great potential for future uses in (i) cereal fermentations for increased mineral bioavailability, and (ii) feed production to increase the phosphate bioavailability for monogastric animals to reduce the need for artificial phosphate fortification.