Marlene Castro, Siguang Sui, and Wei-Shou Hu. Department of Chemical Engineering and Materials Science, University of Minnesota, 151 Amundson Hall, 421 Washington Ave SE, Minneapolis, MN 55455
Secondary metabolites production in Streptomycetes is regulated by a complex, dynamic, interactive network, which is linked to morphological differentiation and mediated by many signaling systems. One of the most common signaling systems used by prokaryotes to detect environmental changes and trigger mechanisms for their adaptation and survival is two-component systems (TCSs). In most cases, however, both the signal detected by TCSs and the response triggered by them are unknown. More than 70 putative TCSs were predicted in the genome of Streptomyces coelicolor, possibly contributing to its versatility to dwell in vastly different environments. In order to study the capability of Streptomyces coelicolor to growth under different environmental conditions, more than 30 regulatory mutants, most of them altered in TCSs, were screened under different growth conditions, including complex and defined media, different carbon and nitrogen sources, temperatures, and pH conditions. Two of the mutants, altered in two different TCSs, were selected for further study based on observed changes in phenotype. These mutants present a bald phenotype, and produce a green pigment, potentially a yet unisolated secondary metabolite. Temporal transcription analysis of these mutants and wild type strain was performed using DNA microarrays. The role of these TCSs in the production of secondary metabolites and morphological differentiation will be discussed, as well as their potential involvement in crossregulation. This work emphasizes the integration of phenotype and transcriptome studies in deciphering the regulatory network of secondary metabolites production.
