I am currently producing a recombinant protein via X-33 Pichia pastoris but production level is not enough. I've used Pgapz alpha a as the vector and YEPD as the medium. I'm using 10 ml YEPD for pre-culture and on the following day I'm transferring it into 100ml YEPD in 1L conical flask for 3 days, all incubations happening in 30 degree Celcius. I could not find effective strategies to upregulate GAP promoter just like AOX1. Can you help me to optimize my conditions? Thanks a lot.
Hi there,
GAP promoter is constitutive so there is no specific adjustment you may consider to improve the yield. If you intend to keep on working with the same system, you may consider to optimize the culture using a bioreactor to increase biomass and optimize the feeding of the culture.
Dear Dominique and Dear Jorg, thank you for your advices. I am going to focus on the growth conditions, maybe lower temperatures than 30 Celcius could work as I read from a review.