Fig. 2

Phylogenetic distribution of CMM pathways and pathway co-occurrence in central metabolism. Presence and absence of 12 key pathways related to energy metabolism including glucose oxidation pathways (glycolysis, ED, TCA cycle, and pentose phosphate) and fermentation pathways (lactate, acetate, formate, ethanol, 2,3-butanediol, butyrate, butanol, and acetone) computed using Boolean rules. Taxonomic groups that are displayed in the horizontal axis of the graph were sorted sequentially as they appear in a 16 s rRNA based phylogenetic tree. The distribution patterns of these key pathways among major phylogenetic groups and pairwise comparisons of pathway presence or absence shows that most pathways are positively correlated. Blue pie slices show comparisons with positive correlations in the clockwise direction while red pie slices show negative relationships in the counterclockwise direction. Relationships shown in pies outlined in bold were consistent across all size classes. Increasing strength of correlation is denoted by increased pie slice size as well as color intensity. Empty pies are relationships that are not significant at p < 0.05. Filled pies are self-comparisons