The three new superior strains exhibited significantly increased tolerance to various inhibitors in spruce hydrolysate, faster growth rate in glucose medium and a faster glucose consumption rate and higher ethanol accumulation capacity in very high gravity fermentations.
In summary, the performances of shorter lag phase time, higher GOD activity, faster glucose consumption rate, the highest productivity and yield, and the highest OUR level in 300 g/L condition were much better than those under other conditions.
It has previously been reported that, whereas overexpression of the transcription factor YAP1 resulted in a strain with a faster sugar consumption rate when fermenting 60% (v/v) of spruce hydrolysate, the same strain was severely inhibited at higher concentrations of the substrate (Alriksson et al. [2010]).
The low concentrations of xylose present inside the cell would improve the apparent kinetic properties of cellobiose phosphorylation, resulting in a faster cellobiose consumption rate.
In contrast, the EGF concentration in the CM of HER2 and HER3 cell lines dropped to the pg/ml level at the 24 h time point, indicating a faster EGF consumption rate in these two cell lines.
Glucose and mannose (derived from the hydrolysate) were completely consumed in less than 10 h by all three strains as well as by the control strains HDY.GUF5 and GS1.11-26, with GSF767 showing the fastest glucose consumption rate, using all glucose in 4 h.
The acetate production rate by B49 was much faster than the consumption rate of R. faecalis RLD-53.
The overexpression of these three genes might explain the phenomenon of fast inulin consumption rates.
The natural petroleum can not catch-up the current consumption rate, which is already reported to be 105 times faster than nature can create.
However, this interpretation did not take into account the possibility of an increase in oxygen consumption rate or the potential contribution of oxygen from fast-flow capillaries.
