Difference in Time of Audible Sound Exposure to Chlorella DPK-01 in Tubular Photobioreactors: A Strategy to Improve Photobioreactor System

The cultivation of Chlorella DPK-01 in tubular photobioreactors (PBRs) with difference in time of audible sound exposure was done. The study aims to evaluate the effect of difference in time of audible sound exposure in tubular PBRs to the growth and lipid percentage of microalgae Chlorella DPK-01. This study was using three groups of Chlorella DPK-01 PBRs. One group was control group and not exposed to any sound (Control-PBR), one group was exposed to audible sound in the light (PBR-A), and another group was exposed to audible sound in the dark (PBR-B). Each group consists of three units of PBR. The audible sound (279.9 Hz sine wave) was played in the light for PBR-A and in the dark for PBR-B. The observation period was 14 days. The growth rate of Chlorella DPK-01 was 47.6% per day (Control-PBR), 0.44 per day (PBR-A), and 0.55 per day (PBR-B) respectively. Meanwhile, the lipid percentage of Chlorella DPK-01 was 16% (Control-PBR), 31% (PBR-A), and 11% (PBR-B) respectively. Therefore, exposing audible sound in the light and in the dark may differently affect the growth and lipid production of Chlorella DPK-01.