For a more robust sugar fermentation, co-consumption of d-glucose and d-xylose is desired as d-xylose fermentation is in particular prone to inhibition by compounds present in pretreated lignocellulosic feedstocks.
As expected, the EC1118 fermentation was more robust than the S288C homozygous and heterozygous deletion mutant pools as ethanol production reached a plateau after 6 days of fermentation, whereas the S288C pools continued to produce ethanol over the entire 14-day period.
Many of the calibration data for glucose in the hydrolysate fermentation fell below 0.03 g/L; removing these data provided a more robust model for glucose in the hydrolysate fermentation however this left only 19 reference points for modelling.
It was noticed that the chitosan-covered calcium alginate beads were slightly more robust than the calcium alginate beads after eight sequential fermentation cycles.
The data obtained in this study are expected to be useful for molecular engineering as well as for screening for more robust strains that may potentially be useful in bioethanol fermentation.
Our findings provide a biotechnological basis for the molecular engineering as well as for screening of more robust yeast strains that may potentially be useful in bioethanol fermentation.
The identified genes stand as preferential targets for genetic engineering manipulation in order to generate more robust industrial strains, able to cope with the most significant fermentation stresses and, thus, to increase ethanol production rate and final ethanol titers.
Here, we discuss the mode of inhibition induced by vanillin and the design of a more robust strain of S. cerevisiae to increase the efficiency of bioethanol fermentation.
The use of genetic engineering approaches to increase the expression of the selected genes in industrial strains is the next logical step, to find out whether these manipulations may lead to the generation of more robust industrial yeast strains, able to cope with the most significant fermentation stresses and, thus, to increase ethanol production rate and final ethanol titers.
The availability of the ISA1307 genome sequence also paves the way to a better understanding of the genetic mechanisms underlying the generation and selection of more robust hybrid yeast strains in the stressful environment of wine fermentations.
