Microfluidic cytometer for characterizing photosynthetic efficiency and lipid accumulation in algae

Figure 1. Image of the diatom Phaeodactyl tricornutum, with red fluorescence indicating the presence of lipid droplets accumulated in the cell.

Unicellular photosynthetic organisms (e.g. - phytoplankton, algae, cyanobacteria) are the world’s dominant primary producers and account for ~ 45% of all carbon fixation. They are taxonomically diverse with over 10,000 species identified. These organisms have a strong potential to produce precursors for biofuels and high-value chemicals. However, production of these precursors varies greatly both among these species and within populations of a single species (often driven by growth conditions). The reasons for these variabilities are not fully understood since information on individual algal cells under natural conditions is currently inaccessible.  Our research focuses on novel technologies developed in our lab (using custom-designed, multifunction, high-through-put, analytical instruments) that simultaneously evaluate, in individual cells, photosynthetic efficiency (utilization of solar energy), oil/biomass production potential and other photophysical properties. In light of the critical importance of these photosynthetic microorganisms for human health, energy needs, and ecosystem sustainability – and in the absence of established technology for the characterization of microbial functional diversity – this research addresses an urgent need.

Components of this project include (i) studies of laboratory-grown cyanobacterial and algal cultures, (ii) development of new measurement techniques to monitoring parameters needed to differentiate individual cells in mixed natural communities, (iii) assessment of the functional diversity within communities and (iv) development of improved strains using screening and directed evolution techniques. The results of this research are expected to lead to new species identification, characterization of natural environments, changes in microbial oil/biomass content, and identification of photosynthetic microorganisms with superior properties leading to economically competitive biofuel and high-value chemical production.

Our collaborations with other laboratories bring expertise to our research in diverse areas that includes specialists in limnology, biology, biochemistry, biophysisics and photobiologists thus providing the necessary intersection of novel technology and ecological expertise.