lose ▁and ▁ara bin ose ▁which ▁are ▁important ▁components ▁of ▁l ign oc ell ulos ic ▁hydro ly s ates . ▁Un like ▁E . ▁col i ▁and ▁ye ast , ▁Z . ▁mobil is ▁cannot ▁toler ate ▁to xic ▁in hib itors ▁present ▁in ▁l ign oc ell ulos ic ▁hydro ly s ates ▁such ▁as ▁ac etic ▁acid ▁and ▁various ▁phen ol ic ▁comp ounds . ▁Con cent r ation ▁of ▁ac etic ▁acid ▁in ▁l ign oc ell ulos ic ▁hydro ly s ates ▁can ▁be ▁as ▁high ▁as ▁ 1 . 5 % ▁( w / v ), ▁which ▁is ▁well ▁above ▁the ▁toler ance ▁threshold ▁of ▁Z . ▁mobil is . ▁ ▁Several ▁attempts ▁have ▁been ▁made ▁to ▁engineer ▁Z . ▁mobil is ▁to ▁overcome ▁its ▁inher ent ▁def ic ien cies . ▁National ▁Ren ew able ▁Energy ▁Labor atory ▁( N RE L ), ▁USA ▁has ▁made ▁significant ▁contributions ▁in ▁expand ing ▁its ▁substr ate ▁range ▁to ▁include ▁C 5 ▁sug ars ▁like ▁x y lose ▁and ▁ara bin ose ., ▁Ac etic ▁acid ▁resist ant ▁stra ins ▁of ▁Z . ▁mobil is ▁have ▁been ▁developed ▁by ▁rational ▁met abol ic ▁engineering ▁efforts , ▁mut agen esis ▁techniques ▁ ▁or ▁adapt ive ▁mut ation ., ▁However , ▁when ▁these ▁engine ered ▁stra ins ▁met abol ize ▁mixed ▁sug ars ▁in ▁presence ▁of ▁in hib itors , ▁the ▁yield ▁and ▁product ivity ▁are ▁much ▁lower , ▁thus ▁prevent ing ▁their ▁industrial ▁application . ▁ ▁An ▁extensive ▁adaptation ▁process