MAC and RYT treatments evolved different metabolite production and consumption profiles.

<p>(A) Ratio (fold change) of ethanol yields of clones selected from MAC and RYT with respect to the ancestor is presented here. A fold change more than 1 indicates ethanol yield of ancestor is lower than MAC or RYT strain being compared with. The relative ethanol yield of MAC is significantly greater than RYT and ancestor strains (Mann-Whitney U, <i>p</i> < 10⁻⁴). The fermentative yeast <i>S</i>.<i>cerevisiae</i> CEN.PK113-7D (0.38g/L) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0173318#pone.0173318.ref037" target="_blank">37</a>] has 1.83 fold higher ethanol yield than the <i>L</i>. <i>kluyveri</i> ancestor (0.207g/L). (B) Time course of the numbers of <i>P</i>. <i>agglomerans</i> bacteria during co-culture with MAC (Triangles), RYT (Bullets) and ancestral strains (Squares), the time course of duplicate clones of <i>P</i>. <i>agglomerans</i> (Diamonds) in absence of yeasts as control (MAC vs RYT and ancestor Mann-Whitney U, <i>p</i> < 0.01). The decrease in bacteria can be attributed to reduction in carbon source. Ethanol (C, D) and acetate (E, F) production in MAC pure and co-cultures was significantly greater than RYT and ancestor strains (Mann-Whitney U, <i>p</i> < 0.01) and the peak of ethanol production in MAC strains coincides with the time point at which <i>P</i>. <i>agglomerans</i> was decimated. Glucose (G, H) was consumed by MAC at half the time that of RYT and ancestor strains in pure and co-cultures (Mann-Whitney U, <i>p</i> < 0.01). Error bars are one standard deviation and ancestor (green), RYT (blue), MAC (orange) and bacteria (<i>P</i>. <i>agglomerans</i>) (olive).