By degrading phytate, the major phosphorus storage compound in animal feed, to release available phosphorus, phytase helps to reduce mineral phosphate consumption and anti-nutritive effect of phytate, and it can also prevent the environmental pollution due to phosphorus excretion
Development of the effective recombinant expression technology is very significant for development of additives in feedstuffs.
In this study, we focused on the improvement of recombinant phytase expression level in methanol induction fermentation by intermittent feeding of glucose, which is well-known as cause the repressive effect on AOX1 promoter in recombinant protein expression with methylotrophic yeast, P. pastoris.
According to the result, in flask cultivation, while methanol induction point and methanol concentration significantly affected the phytase expression, glucose addition in induction phase could enhance phytase expression.
In bioreactor fermentation, the intermittent glucose feeding showed several advantageous results such as 68 h longer activity increment, 149.2% higher cell density and 200.1% higher activity compared to the sole methanol feeding method.
Glucose intermittent feeding could be exploited for economic phytase production by P. pastoris.
This result of our research was published in "Brazilian Journal of Microbiology" under the title of "Improvement of the recombinant phytase expression by intermittent feeding of glucose during the induction phase of methylotrophic yeast Pichia pastoris"(https://doi.org/10.1007/s42770-024-01385-z).
