Manipulating the biomass composition of Arthrospira platensis through high frequency acoustic treatments

Photosynthetic microorganisms such as Arthrospira platensis are considered a more sustainable source of bioactive compounds. Moreover, their biomass composition can be altered by subjecting these cultures to physical or chemical stresses, at the expense of reduced growth rates. Alternative approaches such as external fields stimuli could enhance biomass composition while minimizing the negative impact on its growth. This study explores the impact of mild acoustic radiation on the compositions of A. platensis . Acoustic treatment variables such as power (ranging from 25% to 75%), frequency (in the range of 578 to 1148 kHz), duration (from 5 to 15 minutes) and culture age (from 4 to 12 days) were investigated using a custom multifactorial Design of Experiments approach. As a result, maximum increase in protein, lipids and carbohydrate concentrations of 10%, 96% and 88% respectively were observed with negligible impact on growth rates. This increase was achieved under different optimized acoustic treatment conditions. These findings could specifically maximize the production of certain compounds without sacrificing growth rates, fine-tunning the A. platensis biomass for various applications. • A novel mild and tunable product stimulation strategy was developed for A. platensis ; • Acoustic frequency, intensity, duration and application timing were investigated; • High-frequency acoustic radiation enhanced the biomass composition of A. platensis ; • Optimal acoustic radiation treatments did not negatively affect cell proliferation; • Lipid and carbohydrate content was doubled under optimal acoustic treatments.