A Microfluidic Platform for Long-Term Monitoring of Algae in a Dynamic Environment

Abstract

Culturing cells in microfluidic “lab-on-a-chip” devices for time lapse microscopy has become a valuable tool for studying the dynamics of biological systems. Although microfluidic technology has been applied to culturing and monitoring a diverse range of bacterial and eukaryotic species, cyanobacteria and eukaryotic microalgae present several challenges that have made them difficult to culture in a microfluidic setting. Here, we present a customizable device for the long-term culturing and imaging of three well characterized strains of cyanobacteria and microalgae. This platform has several advantages over agarose pads and demonstrates great potential for obtaining high quality, single-cell gene expression data of cyanobacteria and algae in precisely controlled, dynamic environments over long time periods.

Review of Microfluidic Photobioreactor Technology for Metabolic Engineering and Synthetic Biology of Cyanobacteria and Microalgae

“…However, the cells are cultivated within the droplet with a fixed amount of nutrient medium and will not be in a well-defined constant chemical environment as the metabolic waste accumulated. The flow based reactors based mLSI technolgy with PDMS material provide well-defined chemical environments and with single cell resolution is still the most ideal choice to obtain the characterization of genetic circuit [ 43 ]. DMF seems to be a unnatural choice for cultivation of cyanobacteria and microalgae mainly because prevention of the evaporation of medium require extensive engineering [ 50 ].…”

“…The chemical environment in each chamber was independently controlled and used to monitor lipid production under nitrogen depletion, phototaxis behavior in the absence of calcium ion and cytotoxic effects due to herbicides. Luke et al developed a Dial-a-Wave (DAW) microfluidic platform for long term monitoring of cyanobacteria and microalgae [ 43 ]. In their system, cells are confined in a microfluidic chamber with height slightly lower than the dimensions of the cell and allowed to grow under the perfusion of nutrient medium.…”

Dynamic Environmental Control in Microfluidic Single‐Cell Cultivations: From Concepts to Applications

“…A similar concept used Luke et al [ 80 ] for the fluid flow with a dial a wave system (DAW) which allows a temporal control of medium and generated a combination of the two inputs defined by the user. They analyzed the effect of limiting nitrogen concentrations onto cell proliferation and chlorophyll autofluorescence of the microalgae Chlorella sorokiniana .…”

“…Furthermore, automated programmable microfluidic platforms that combine image‐based single‐cell analysis and DCE with feedback control are emerging. [ 50,56,78–80 ] Here, cellular behavior is controlled by real time image analysis of cells, coupled to dynamic environmental control. [ 96,97 ] As soon as cellular threshold values are reached defined medium pulses are triggered (referred as negative feedback control).…”

The potential of quantitative models to improve microalgae photosynthetic efficiency

“…To address these challenges, the ability to design the experiments maximizing the information that may be collected (Bernardi et al ), and to efficiently collect large experimental dataset testing the effect of multiple parameters will be strategic. In this perspective, the development of micro‐scale devices (Kim et al , Luke et al , Perin et al ) is opening the possibility to investigate the effect of multiple variables (e.g. light intensity, CO 2 and nutrients availability, temperature) on microalgae physiology, thus reducing experimental time and costs, and to rapidly tune models to different strains.…”