High-Throughput In Vitro Screening of Changed Algal Community Structure Using the PhotoBiobox

In a previous study, the sequential optimization and regulation of environmental parameters using the PhotoBiobox were demonstrated with high-throughput screening tests. In this study, we estimated changes in the biovolume-based composition of a polyculture built in vitro and composed of three algal strains: Chlorella sp., Scenedesmus sp., and Parachlorella sp. We performed this work using the PhotoBiobox under different temperatures (10-36°C) and light intensities (50-700 μmol/m^-2/s^-1) in air and in 5% CO₂. In 5% CO₂, Chlorella sp. exhibited better adaptation to high temperatures than in air conditions. Pearson's correlation analysis showed that the composition of Parachlorella sp. was highly related to temperature whereas Chlorella sp. and Scenedesmus sp. showed negative correlations in both air and 5% CO₂. Furthermore, light intensity slightly affected the composition of Scenedesmus sp., whereas no significant effect was observed in other species. Based on these results, it is speculated that temperature is an important factor in influencing changes in algal polyculture community structure (PCS). These results further confirm that the PhotoBiobox is a convenient and available tool for performance of lab-scale experiments on PCS changes. The application of the PhotoBiobox in PCS studies will provide new insight into polyculture-based ecology.