▁ 1 , ▁the ▁third ▁en zym e ▁in ▁the ▁g ly col ysis ▁path way . ▁The ▁P aste ur ▁effect ▁will ▁only ▁occur ▁if ▁gl uc ose ▁concentr ations ▁are ▁low ▁( < 2 ▁g / L ) ▁and ▁if ▁other ▁nut ri ents , ▁mostly ▁nit ro gen , ▁are ▁limited . ▁ ▁From ▁the ▁stand point ▁of ▁ATP ▁production ▁then , ▁it ▁is ▁advantage ous ▁for ▁ye ast ▁to ▁util ize ▁the ▁cit ric ▁acid ▁cycle ▁in ▁the ▁presence ▁of ▁o xygen , ▁as ▁more ▁ATP ▁is ▁produced ▁from ▁less ▁gl uc ose ; ▁however , ▁B oul ton ▁et ▁al . ▁( 1 9 9 6 ) ▁have ▁maintained ▁that ▁ye ast ▁will ▁follow ▁the ▁an a er ob ic , ▁rather ▁than ▁aer ob ic , ▁fer ment ative ▁path way ▁if ▁gl uc ose ▁is ▁not ▁limited , ▁in ▁that ▁resp iration , ▁although ▁capable ▁of ▁producing ▁more ▁ATP ▁than ▁g ly col ysis ▁per ▁mole c ule ▁of ▁gl uc ose , ▁also ▁requires ▁more ▁energy ▁in ▁terms ▁of ▁en zym atic ▁and ▁mit och ond rial ▁requirements . ▁ ▁Pract ical ▁imp lications ▁The ▁processes ▁used ▁in ▁alco hol ▁production ▁are ▁commonly ▁maintained ▁in ▁a ▁low ▁o xygen ▁condition , ▁under ▁a ▁blank et ▁of ▁carbon ▁dio x ide , ▁while ▁bre eding ▁ye ast ▁for ▁bi om ass ▁is ▁done ▁in ▁aer ob ic ▁conditions , ▁the ▁bro th ▁being ▁aer ated . ▁ ▁See ▁also ▁ ▁Eth an ol ▁fer ment ation