Growth comparison of Arthrospira platensis in different vessels: standard cylinder vs. enhanced surface area at low light

Abstract

A laboratory scale prototype of a novel tube called AlgaTube™ (patent pending) was evaluated for growth of Arthrospira platensis (commonly referred to as Spirulina) in a controlled, 10-day batch trial at low light intensity. The two cultures (control and prototype) were grown in identical conditions inside a closed incubator space at 32°C with a mean light intensity of 55 µmol photons m−2 s−1 LED light, consisting mostly of red and blue wavelengths with some full spectrum background radiation. OD590 was measured daily and converted to Concentration (Cd, g l−1) using a standard curve. Four independent replicates of the trial were run. Six biomass growth metrics were evaluated and compared. Across the board, all six growth metrics showed higher rates of biomass growth in the AlgaTube™. Maximum concentration was 34% higher (p = 0.02), cumulative production was 41% higher (p = 0.02), specific growth rate was 17% higher (p = 0.02), maximum specific growth rate was 23% higher (p = 0.02), mean daily production was 41% higher (p = 0.001), and maximum daily production was 38% higher (p = 0.19). We conclude that the novel shape of the AlgaTube™ prototype increased biomass growth rates. We believe that this study constitutes successful proof-of-concept for the AlgaTube™, but further studies are needed to optimize its performance.