An improved open-source software platform for high-throughput cultivation of phototrophic microorganisms and its application for salt tolerance experiments

High-throughput screening and cultivation methods offer significant potential to accelerate the development of phototrophic microorganisms into microbial cell factories. To date, however, only few suitable platforms have been reported, often lacking adequate methods for automated data handling and analysis. Here we report an improved high-throughput cultivation and screening platform that incorporates a newly developed open-source laboratory information and management system implemented using the R package Shiny. The PhotoScreener Viewer allows the user to automatically backup the collected data, provides methods for interactive graphical representation of data, including a set of statistical tests. Furthermore, the platform enables authorized users to create, view and edit their experiments online. As an advanced application study for the improved platform, we consider the response of an ethanol-producing cyanobacteria to varying salinity of the culture medium. Based on the conjecture that high-salt conditions impact the productivity of a ethanol-producing modified strain of Synechocystis sp. PCC 6803, we monitor growth, vitality and ethanol production using cultivation in 96-deep-well plates within the robotic platform. We could not observe an increased ethanol production, but rather the opposite.