BioChem - DOS

Transporter engineering for cellobiose fermentation under lower pH conditions by engineered Saccharomyces cerevisiae

Bioresource technology : biomass, bioenergy, biowastes, conversion technologies, biotransformations, production technologies

Oh, Eun Joong; Kwak, Suryang; Kim, Heejin; Jin, Yong-Su

<P><B>Abstract</B></P> <P>The aim of this study was to engineer cellodextrin transporter 2 (CDT-2) from <I>Neurospora crassa</I> for improved cellobiose fermentation under lower pH conditions by <I>Saccharomyces cerevisiae</I>. Through directed evolution, a mutant CDT-2 capable of facilitating cellobiose fermentation under lower pH conditions was obtained. Specifically, a library of CDT-2 mutants with GFP fusion was screened by flow cytometry and then serial subcultured to isolate a CDT-2 mutant capable of transporting cellobiose under acidic conditions. The engineered <I>S. cerevisiae</I> expressing the isolated mutant CDT-2 (I96N/T487A) produced ethanol with a specific cellobiose consumption rate of 0.069g/gcell/h, which was 51% and 55% higher than those of the strains harboring wild-type CDT-1 and CDT-2 in a minimal medium with 2g/L of acetic acid.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Directed evolution of cellobiose transporter CDT-2 was attempted. </LI> <LI> A mutant CDT-2 facilitating cellobiose fermentation at lower pH levels was isolated. </LI> <LI> The mutant CDT-2 showed better fermentation under both neutral and acidic conditions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

2017

Elsevier

0960-8524

245

2

pp.1469-1475

10.1016/j.biortech.2017.05.138

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART78806251

Saccharomyces cerevisiae; Cellobiose; Cellodextrin transporter; Low pH conditions; Transporter engineering