Optogenetic tools for public goods control in Saccharomyces cerevisiae

Abstract

Microorganisms live in dense and diverse communities, with interactions between cells guiding community development and phenotype. The ability to perturb specific intercellular interactions in space and time provides a powerful route to determining the critical interactions and design rules for microbial communities. Approaches using optogenetic tools to modulate these interactions offer promise, as light can be exquisitely controlled in space and time. We report new plasmids for rapid integration of an optogenetic system into Saccharomyces cerevisiae to engineer light-control of expression of a gene of interest. In a proof-of-principle study, we demonstrate the ability to control a model cooperative interaction, namely the expression of the enzyme invertase (SUC2) which allows S. cerevisiae to hydrolyze sucrose and utilize it as a carbon source. We demonstrate that the strength of this cooperative interaction can be tuned in space and time by modulating light intensity and through spatial control of illumination. Spatial control of light allows cooperators and cheaters to be spatially segregated, and we show that the interplay between cooperative and inhibitory interactions in space can lead to pattern formation. Our strategy can be applied to achieve spatiotemporal control of expression of a gene of interest in Saccharomyces cerevisiae to perturb both intercellular and interspecies interactions. ImportanceRecent advances in microbial ecology have highlighted the importance of intercellular interactions in controlling the development, composition and resilience of microbial communities. In order to better understand the role of these interactions in governing community development it is critical to be able to alter them in a controlled manner. Optogenetically-controlled interactions offer advantages over static perturbations or chemically-controlled interactions as light can be manipulated in space and time and doesnt require the addition of nutrients or antibiotics. Here we report a system for rapidly achieving light-control of a gene of interest in the important model organism Saccharomyces cerevisiae and demonstrate that by controlling expression of the enzyme invertase we can control cooperative interactions. This approach will be useful for understanding intercellular and interspecies interactions in natural and synthetic microbial consortia containing Saccharomyces cerevisiae and serves as a proof-of-principle for implementing this approach in other consortia.