Figure 3

Functional metabolic decomposition of baculovirus-producing S. frugiperda 's cells. (A) Performance of predictive MFA in describing baculovirus productivity based on metabolic data from 13 independent cultures (see Table 2). In all cases, Sf 9 insect cells were infected with a low multiplicity of infection in serum-free medium. A total of 3 latent variables were used to describe the data. Productivity is expressed in 10³ infectious particles × (10⁶ cells × h)^-1. (B) In order to estimate confidence intervals for the model regression coefficients, Monte Carlo sampling was used to generate 1000 data matrices based on the error variances of all predictor and target variables (see Methods section for details). The strength of association (α) was defined as the confidence interval to regression coefficient ratio, allowing the exclusion of those fluxes with α values lower than 1. (C) After hierarchical clustering, the TCA cycle and mitochondrial respiration naturally arised as a closely connected group of fluxes strongly correlated with high productivities. With lighter association strengths, one additional cluster corresponds to the catabolization fluxes of the essential amino acids phenylalanine, methionine and histidine. Abbreviations: ACoA (acetyl-coenzyme A), Cit (citrate), Fum (fumarate), His (histidine), Mal (malate), Met (methionine), OAA (oxaloacetate), Phe (phenylalanine), Pyr (pyruvate), Suc (succinate), SuCoA (succinyl-coenzyme A), αKG (α-ketoglutarate).