초록
<P><B>Abstract</B></P> <P>In this work, a recombinant cyanobacterium strain with increased photosynthesis rate, cell growth and carbohydrate production efficiency was genetically engineered by co-expressing <I>ictB</I>, <I>ecaA</I>, and <I>acsAB</I> (encoded for bacterial cellulose) in <I>Synechococcus elongatus</I> PCC7942. The resulting cyanobacterial biomass could be effectively hydrolyzed with dilute acid (2% sulfuric acid), achieving a nearly 90% glucose recovery at a biomass concentration of 80g/L. Bioethanol can be produced from fermenting the acidic hydrolysate of <I>S. elongatus</I> PCC7942 via separate hydrolysis and fermentation (SHF) process at a concentration of 7.2g/L and with a 91% theoretical yield.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Carbohydrate production of <I>S. elongatus</I> producing bacterial cellulose was enhanced. </LI> <LI> Over-expressing <I>ictB</I> and <I>ecaA</I> markedly increases the photosynthesis and growth rate. </LI> <LI> Co-expression of <I>ictB</I>, <I>ecaA</I>, and <I>acsAB</I> improves the carbohydrate productivity. </LI> <LI> The microalga can be used for bioethanol production after dilute acid hydrolysis. </LI> </UL> </P>