Figure 4

Expression of P. chrysogenum secondary metabolism genes during co-cultivation with B. subtilis . Heat map of transcript levels of genes encoding NRPS (and -like), PKS (and -like) and hybrid NRPS-PKS in strain Wisconsin 54–1255, grown in aerobic glucose-limited chemostat cultures, 0 h, 5 h, 24 h, 48 h and 72 h after addition of B. subtilis. The expression data were derived from hybridization intensity of Affymetrix DNA microarrays (DSM PENa520255F) (n = 3). The transcript data were Z-normalized for each experiment. Genes that were not expressed in the mixed culture are marked with *and the seven genes whose transcript profile was deemed significantly different from the null situation are marked with #. The numbers between brackets indicate the numbers of NRPS, NRP-like, PKS, PKS-like and hybrids catalogued in the P. chrysogenum genome.