초록
<P><B>Abstract</B></P><P><B>BACKGROUND</B></P><P>This study evaluated the influence of different micro‐aerated conditions, including the aeration rate, the volumetric oxygen transfer coefficient (<I>k</I><SUB>L</SUB>a) and the oxygen transfer rate (OTR), on improving ethanol productivity and scale‐up of the fermentation step of the ethanologenic <I>Escherichia coli</I> strain MS04 in mineral medium supplemented with xylose, glucose, and sodium acetate.</P><P><B>RESULTS</B></P><P>Growth and ethanol production results using 0.75 L of fermenter showed that micro‐aeration (0.1 vvm, 400 rpm) improved the volumetric ethanol productivity and sugar consumption rate compared with the anaerobic condition (0 vvm, 400 rpm) or higher aeration rates (>0.2 vvm) without reducing significantly the ethanol yield. The <I>k</I><SUB>L</SUB>a and the OTR were estimated and a <I>k</I><SUB>L</SUB>a value of 7.2 h<SUP>−1</SUP> was used as a criterion to scale‐up the fermentation process from 0.75 L to 9.16 L and 110 L. During scale‐up, the volumetric ethanol productivity and ethanol yield of consumed sugars were maintained at similar levels to those obtained in the laboratory in the 0.75 L fermenter.</P><P><B>CONCLUSIONS</B></P><P>The controlled supply of low levels of oxygen promoted an increase in the concentration of biomass favoring the production and volumetric productivity of ethanol. The use of <I>k</I><SUB>L</SUB>a allowed the fermentation step to be scaled up with ethanologenic <I>E. coli</I> maintaining similar ethanol yields and productivities. © 2016 Society of Chemical Industry</P>