Figure 3
Optimization of the cellulosome and ethanol production activity by controlling the combination ratio of different cell populations. (A) The optimal ratio of mini CipA (cohesin) to CelA (dockerin). CelA was regarded as a representative of total cells harboring dockerin-fused enzymes. EBY100 cells displaying mini CipA and secreting CelA were combined at the indicated ratios, and the released reducing sugars from PASC were detected using the harvested cells. (B) The optimal ratio of CelA to CBHII. The optimal CelA:CBHII ratio for PASC hydrolysis was determined while fixing the amount of cells displaying mini CipA as 1/4 of total cells. (C) The optimal ratio of BGLI to cellulosome for ethanol production. The optimal amount of BGL1 for ethanol production was determined while fixing the mini CipA:CelA:CBHII ratio of 2:3:3. The bar graph represents inoculation portion of cells containing each plasmid. The square line graph represents released reducing sugars from PASC in each ratio. The triangle line graph represents ethanol concentration after three-day fermentation in each ratio.