▁ ▁is ▁able ▁to ▁grow ▁on ▁simple , ▁in exp ensive ▁medium , ▁with ▁high ▁growth ▁rate . ▁P . ▁past oris ▁can ▁grow ▁in ▁either ▁sh ake ▁flask s ▁or ▁a ▁fer ment er , ▁which ▁makes ▁it ▁suitable ▁for ▁both ▁small - ▁and ▁large - scale ▁production . ▁▁ 2 : P . ▁past oris ▁has ▁two ▁alco hol ▁ox id ase ▁gen es , ▁A ox 1 ▁and ▁A ox 2 , ▁which ▁include ▁strongly ▁indu cible ▁prom ot ers . ▁These ▁two ▁gen es ▁allow ▁P ich ia ▁to ▁use ▁m eth an ol ▁as ▁a ▁carbon ▁and ▁energy ▁source . ▁The ▁A O X ▁prom ot ers ▁are ▁induced ▁by ▁m eth an ol , ▁and ▁repr essed ▁by ▁gl uc ose . ▁Usually , ▁the ▁gene ▁for ▁the ▁desired ▁protein ▁is ▁introduced ▁under ▁the ▁control ▁of ▁the ▁A ox 1 ▁prom oter , ▁which ▁means ▁that ▁protein ▁production ▁can ▁be ▁induced ▁by ▁the ▁addition ▁of ▁m eth an ol ▁on ▁medium . ▁After ▁several ▁research es , ▁scient ists ▁found ▁that ▁the ▁prom ot or ▁derived ▁from ▁A O X 1 ▁gene ▁in ▁P . ▁past oris ▁is ▁extremely ▁suitable ▁to ▁control ▁the ▁expression ▁of ▁foreign ▁gen es , ▁which ▁had ▁been ▁transformed ▁into ▁the ▁P . ▁past oris ▁gen ome , ▁producing ▁heter olog ous ▁prote ins . ▁▁ 3 : ▁With ▁a ▁key ▁trait , ▁P . ▁past oris ▁can ▁grow ▁with ▁extremely ▁high ▁cell ▁density ▁on ▁the ▁culture . ▁This ▁feature ▁is ▁compatible ▁with