Supplements are readily available for figure two: Figure IFN-alpha 1/IFNA1 Protein Storage & Stability supplement 1. Xylosyl-xylitol oligomers generated in
Supplements are available for figure 2: Figure supplement 1. Xylosyl-xylitol oligomers generated in yeast cultures with xylodextrins as the sole carbon source. DOI: 10.7554eLife.05896.012 Figure supplement two. Xylodextrin metabolism by a co-culture of yeast strains to recognize enzymatic source of xylosyl-xylitol. DOI: 10.7554eLife.05896.013 Figure supplement three. Chromatogram of xylosyl-xylitol hydrolysis solutions generated by -xylosidases. DOI: 10.7554eLife.05896.We next tested whether integration of your total xylodextrin consumption pathway would overcome the poor xylodextrin utilization by S. cerevisiae (Figure 1) (Fujii et al., 2011). When combined together with the original xylodextrin pathway (CDT-2 plus GH43-2), GH43-7 enabled S. cerevisiae to develop far more rapidly on xylodextrin (Figure 4A) and eliminated accumulation of xylosyl-xylitol intermediates (Figure 4B and Figure 4–figure supplement 1). The presence of xylose and glucose considerably improved anaerobic fermentation of xylodextrins (Figure 5 and Figure 5–figure supplement 1 and Figure 5–figure supplement two), indicating that metabolic sensing in S. cerevisiae with the total xylodextrin pathway may require more tuning (Youk and van Oudenaarden, 2009) for optimal xylodextrin fermentation. Notably, we observedLi et al. eLife 2015;four:e05896. DOI: 10.7554eLife.five ofResearch articleComputational and systems biology | EcologyFigure three. Xylosyl-xylitol and xylosyl-xylosyl-xylitol production by a range of microbes. (A) Xylodextrin-derived carbohydrate levels observed in chromatograms of intracellular metabolites for N. crassa, T. reesei, A. nidulans and B. subtilis grown on xylodextrins. Compounds are abbreviated as follows: X1, xylose; X2, xylobiose; X3, xylotriose; X4, xylotetraose; xlt, xylitol; xlt2, xylosyl-xylitol; xlt3, xylosyl-xylosyl-xylitol. (B) Phylogenetic tree from the organisms shown to make xylosyl-xylitols during growth on xylodextrins. Ages taken from Wellman et al. (2003); Galagan et al. (2005); Hedges et al. (2006). DOI: 10.7554eLife.05896.015 The following figure supplement is available for figure three: Figure supplement 1. LC-MSMS numerous reaction monitoring chromatograms of xylosyl-xylitols from cultures of microbes grown on xylodextrins. DOI: 10.7554eLife.05896.that the XRXDH pathway made significantly much less xylitol when xylodextrins have been utilised in fermentations than from xylose (Figure five and Figure 5–figure supplement 2B). Taken together, these results reveal that the XRXDH pathway extensively utilised in engineered S. cerevisiae naturally has broad substrate specificity for xylodextrins, and comprehensive reconstitution from the naturally occurring xylodextrin pathway is essential to enable S. cerevisiae to effectively consume xylodextrins. The IL-33 Protein Accession observation that xylodextrin fermentation was stimulated by glucose (Figure 5B) suggested that the xylodextrin pathway could serve far more frequently for cofermentations to enhance biofuel production. We thus tested regardless of whether xylodextrin fermentation might be carried out simultaneously with sucrose fermentation, as a indicates to augment ethanol yield from sugarcane. In this scenario, xylodextrins released by hot water treatment (Hendriks and Zeeman, 2009; Agbor et al., 2011; Vallejos et al., 2012) may very well be added to sucrose fermentations using yeast engineered with all the xylodextrin consumption pathway. To test this idea, we made use of strain SR8U engineered using the xylodextrin pathway (CDT-2, GH43-2, and GH437) in fermentations combining sucrose and xylodextrin.