coelicolor A3(2) M145 wild type and the phoP deletion mutant INB201 [19,20] derived from M145, the latter only cultivated under phosphate limited conditions). The
Selleck Dorsomorphin cultivation platform suitable for full-scale ‘omics sampling [10], as well as the on- and off-line data for the two cultivations involving strain M145 discussed here have previously been reported elsewhere [6,7,8,9]. However, growth Inhibitors,research,lifescience,medical and secondary metabolite production profiles for the selected strains and cultivation conditions are repeated in this report as they are important for the interpretation of the metabolite profiling data. The medium needed supply of two carbon sources, D-glucose and L-glutamate, the latter also serving as the sole source of nitrogen in the medium, to establish a distinct transition between the growth and secondary metabolite production phases as well as to provide enough biomass for full-scale ‘omics sampling already many hours prior to depletion of the respective Inhibitors,research,lifescience,medical limiting nutrient (phosphate in SSBM-P
and L-glutamate in SSBM-E). The S. coelicolor M145 strain showed usual growth and secondary metabolite production onset profiles in the phosphate limited medium (Figure 1, left panel). After a period of linear growth, the culture experienced phosphate depletion Inhibitors,research,lifescience,medical 35 h after inoculation, preventing further growth and triggering the onset of secondary metabolite production. Undecylprodigiosin and actinorhodins were detected in the medium around 5 and 15 h after phosphate depletion, respectively, and in this intermittent Inhibitors,research,lifescience,medical period, the cells abandoned growth, induced the expression of secondary metabolite gene clusters and synthesized the corresponding proteins/enzymes. The phoP deletion mutant INB201 showed very similar growth and secondary metabolite production profiles as the M145 parental strain (Figure 1, middle panel), while the glutamate limitation in M145 wild-type clearly resulted in a much more dramatic physiological response, as seen in a rapid decline in CO2 evolution (Figure 1, Inhibitors,research,lifescience,medical right panel). The secondary
metabolite production rates much are significantly lower in the glutamate limited culture. However, the yield on carbon source basis is not particularly high (<2% w/w) for none of the two media applied (data not shown). In any case, the three cultivations presented here represent a good experimental design to explore how S. coelicolor cells adapt at the metabolite level to the changing cultivation conditions while reprogramming metabolism from growth to secondary metabolite production. Figure 1 Batch cultivation on-line (upper panels) and off-line data (lower panels) obtained for (A) strain M145 on phosphate depletion medium SSBM-P; (B) strain INB201 (ΔphoP) on phosphate depletion medium SSBM-P; and (C) strain M145 on glutamate depletion … 2.2.