Fig. 1

Clustered heat map of all BGPs and their metaprotein profiles generated by hierarchical cluster analysis using the Matlab function “clustergram”. The numbers of metaproteins were normalized to have a mean of 0 and a standard deviation of 1 (see also color key right of the figure). Names of BGPs are below the figure, whereas blue names refer to BGPs operating with mesophilic and red names to BGPs operating with thermophilic process conditions. The colored groups are samples from the same BGP at different time points (dark green SEH) parallel fermenters [Gent 22 (2012-04-04), Gent 24 (2012-04-04)]; green VCE [Gent 15 (2011-10-10), Gent 29 (2012-04-10)]; gray BOEYE [Gent 23 (2012-04-14), Gent 27 (2012-04-11), Gent 35 (2011-09-29)]; orange DRZ [Gent 20 (2011-09-29), Gent 25 (2012-04-04)]; red BCI [Gent 33 (2012-04-11), Gent 39 (2011-09-29)]. After visual assignment, four main clusters of microbial communities are proposed, namely UASB fermenters, thermophile BGPs, mesophile BGP as well as BGPs running with sewage sludge