Pheromone-inducible expression vectors for fission yeast Schizosaccharomyces pombe

A lncRNA-regulated gene expression system with rapid induction kinetics in the fission yeast Schizosaccharomyces pombe

The fission yeast Schizosaccharomyces pombe is an excellent model organism for the study of eukaryotic cellular physiology. The organism is genetically tractable and several tools to study the functions of individual genes are available. One such tool is regulatable gene expression and overproduction of proteins. Limitations of currently available overexpression systems include delay in expression after induction, narrow dynamic range, and system-wide changes due to induction conditions. Here I describe a new long noncoding RNA (lncRNA)-regulated, thiamine-inducible expression system that integrates lncRNA-based transcriptional interference at the fission yeast tgp1 promoter with the fast repression kinetics of the thiamine-repressible nmt1 promoter. This hybrid system has rapid induction kinetics, broad dynamic range, and tunable expression via thiamine concentration. The lncRNA-regulated thiamine-inducible system will be advantageous for the study of individual genes and for potential applications in the production of heterologous proteins in fission yeast.

New approaches in bioprocess-control: Consortium guidance by synthetic cell-cell communication based on fungal pheromones

Bioconversions in industrial processes are currently dominated by single-strain approaches. With the growing complexity of tasks to be carried out, microbial consortia become increasingly advantageous and eventually may outperform single-strain fermentations. Consortium approaches benefit from the combined metabolic capabilities of highly specialized strains and species, and the inherent division of labor reduces the metabolic burden for each strain while increasing product yields and reaction specificities. However, consortium-based designs still suffer from a lack of available tools to control the behavior and performance of the individual subpopulations and of the entire consortium. Here, we propose to implement novel control elements for microbial consortia based on artificial cell-cell communication via fungal mating pheromones. Coupling to the desired output is mediated by pheromone-responsive gene expression, thereby creating pheromone-dependent communication channels between different subpopulations of the consortia. We highlight the benefits of artificial communication to specifically target individual subpopulations of microbial consortia and to control e.g. their metabolic profile or proliferation rate in a predefined and customized manner. Due to the steadily increasing knowledge of sexual cycles of industrially relevant fungi, a growing number of strains and species can be integrated into pheromone-controlled sensor-actor systems, exploiting their unique metabolic properties for microbial consortia approaches.