Question: 1-butanolproduction

Bioethanol areabletobeproduced from biomass as renewable andenvironmental friendly energy.However,Ethanolhasa highwatercontentandlowenergydensityrelativetogasoline. Recently, 1-butanol wasproposed assubstituteofgasolineasitsenergycontent (27MJ/L) is similarto thatof gasoline(32MJ/L).Itcancompletelyreplacegasolineormixwithgasolineat any ratioandthus be transportedinexistinginfrastructure.

AstartupcompanyhasisolatedaClostridiumacetobutylicumstrainwhichisabletoproduce
1-butanolbyfermentingonwastewaterfroma closebylargewheatprocessingfactory.Theidea ofthestartupcompanyistoformpartnershipwith thiswheatprocessingfactoryand can“freely” use their waste water. Clostridium acetobutylicum is a Gram-positive anaerobe which also producesbyproductssuchas butyrate,acetone,andethanol.Its 1-butanolyieldis difficultto control. As a strict anaerobe, Clostridium acetobutylicum’s relatively slow growth rate and spore-forminglife cyclecreateadditionalproblemsfor industrialfermentation.Furthermore,the relativelyunknowngeneticsystemandcomplexphysiologyof themicroorganismpresent difficultiesinengineeringitsmetabolismfor optimalproductionof 1-butanol.Fortunately,the geneticpathways for1-butanol synthesisisclearinClostridiumacetobutylicum andthusthe scientistsfromthestartupcompanyhasclonedthe1-butanolsynthesisgenessuccessfullyinto a Escherichia colistrain Bu_1for 1-butanolproduction.

However,theEscherichiacoli Bu_1strainstill remainsseverallimitationswhichhinderits large scale1-butanol production. Pleaseprovideaproposaltosolvethesefollowing limitationof EscherichiacoliBu_1strainusing theknowledgeyoulearned.

Question 1)
Accumulationof1-butanol fromEscherichiacoliBu_1 cultures was foundtogradually slowdownthegrowthofEscherichiacoliBu_1strain. Howtodesigna bioreactorthat canreducethegrowthinhibitionofEscherichiacoliBu_1strainbyits ownproduct1-butanol?

Please explain your proposal in a very detailed manner to prepare yourself for your upcoming presentation. Explain the reasons in very detailed form about why you chose this bioreactor design, process flow and important devices required…….etc.
(Pictures and diagrams can be used for illustration).