Project description:Populations of engineered metabolite-producing microorganisms are prone to evolutionary production declines during industrial-scale cultivations. In this study, we develop a synthetic product addiction system in E coli that addicts mevalonic acid production cells to mevalonic acid. Through experimentally simuluated long-term fermentation, we investigate how product-addicted organisms remain stable and avoid formation of genetic subpopulations of fit, non-producing cells.
Project description:We have integrated nucleotide resolution genome-scale measurements of the transcriptome and translatome of the Streptomyces coelicolor A3(2), the model antibiotic-producing actinomycete. Our systematic study determined 3,473 transcription start sites, leading to discovery of a high proportion (~21%) of leaderless mRNAs and 230 non-coding RNAs; this enabled deduction of promoter architecture on a genome-scale. Ribosome profiling analysis revealed that the translation efficiency was negatively correlated for secondary metabolic genes. These results provide novel fundamental insights into translational regulation of secondary metabolism that enables rational synthetic biology approaches to awaken such âsilentâ secondary metabolic pathways. Profiles of primary transcripts, whole transcripts, and ribosome protected fragments (RPFs) of Streptomyces coelicolor were generated by deep sequencing using Illumina Miseq.
Project description:In this work, we identified glucose and glycerol as tacrolimus repressing carbon sources in the important species Streptomyces tsukubaensis. A genome-wide analysis of the transcriptomic response to glucose and glycerol additions was performed using microarray technology. The transcriptional time series obtained allowed us to compare the transcriptomic profiling of S. tsukubaensis growing under tacrolimus producing and non-producing conditions. The analysis revealed important and different metabolic changes after the additions and a lack of transcriptional activation of the fkb cluster. In addition, we detected important differences in the transcriptional response to glucose between S. tsukubaensis and the model species Streptomyces coelicolor. A number of genes encoding key players of morphological and biochemical differentiation were strongly and permanently downregulated by the carbon sources. Finally, we identified several genes showing transcriptional profiles highly correlated to that of the tacrolimus biosynthetic pathway regulator FkbN that might be potential candidates for the improvement of tacrolimus production
