Application of the PLP algorithm to the analysis of envirome data collected from six BHK cultures as described in Methods and Table 1. Data from the growth stage of every experiment were pooled together. (a) Correlation between measured extracellular rates (R) and predicted rates obtained by reconstruction of fluxes of discriminated EMs. Units are in nmol.(106cells.h)-1. (b) Ranking of first 20 EMs that correlate with the envirome, explaining 93% of the variance in the measured extracellular rates. These pathways correspond to typical routes known to be active in cultured mammalian cell lines. Refer to the text for a description.