Metabolic switches and adaptations deduced from the proteomes of Streptomyces coelicolor wild type and phoP mutant grown in batch culture

Bacteria in the genus Streptomyces are soil dwelling oligotrophs and important producers of secondary metabolites. Previously we showed that global mRNA expression was subject to a series of metabolic and regulatory switches during the life time of a fermentor batch culture of S. coelicolor M145. Here we analyse the proteome from eight time points from the same fermentor culture and, as phosphate availability is an important regulator of secondary metabolite production, compare this to the proteome of a similar time course from an S. coelicolor mutant, INB201 (ΔphoP), defective in the control of phosphate utilisation. The proteomes provide a detailed view of enzymes involved in central carbon and nitrogen metabolism. Trends in protein expression over the time courses were deduced from a protein abundance index which also revealed the importance of stress pathway proteins in both cultures. As expected the ΔphoP mutant was deficient in expression of PhoP-dependent genes and several putatively compensatory metabolic and regulatory pathways for phosphate scavenging were detected. Notably there is a succession of switches that co-ordinately induce the production of enzymes for five different secondary metabolite biosynthesis pathways over the course of the batch cultures and these were not confined to the stationary phase. 36 samples, no replicates; one hour resolution from 23-36h and 41-48h; half hour resolution from 36-41h; two hour resolution 48-60h; sample missing for 34 h