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

Abstract

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.

Effect of Audible Sound Exposure on the Growth and Lipid Content of Chlorella DPK-01 Cultivated in Photobioreactor System using Different Growth Media

“…These results are quite higher compared to previous research where Chlorella DPK-01 were cultivated in BBM with exposure to sine soundwave under different photoperiods. The lipid percentage of Chlorella DPK-01 in previous research ranges from 11% to 31% 13) . The bar chart shows that Chlorella DPK-01, which had the highest lipid content among the BBM group, was cultured in PBR BBM-Square (51.43%).…”

“…Photobioreactors (PBRs) and incubation cabinet in this study were designed and assembled identically with previous studies by Tambunan et al 13) and Santoso et al 29) . That system has been proven suitable for studies involving audible soundwaves exposure to microalgae, both prokaryotic 29) and eukaryotic 13) . The tube-shaped PBRs are made from 3 mm acrylic.…”

“…Prokaryotic microalgae Stanieria HS-48 underwent an adaptation phase for about 2 days when transferred from Erlenmeyer flask filled with BBM into airlift photobioreactor filled NPK Fertilizer Media, with and without the addition of bean sprout extract 25) . Chlorella DPK-01 itself, as eukaryotic microalgae, also underwent an adaptation phase for about 2 days when exposed to different photoperiods 13) . Adaptation phase or lag phase takes place before the growth process takes place.…”

“…The strain code of this Depok Isolated Chlorella is Depok number one or DPK-01. A previous study has shown that microalga Chlorella DPK-01 can produce lipids up to 31% of its biomass 13) .…”

Biomass Production of Subang Isolated Scenedesmus in Tube-shaped Photobioreactor with the Exposure of Audible Sound (Music): Photobioreactor Improvement Strategy

“…Design of the incubation cabinet and photobioreactor in this study was similar to the design that was used by Tambunan et al (2021) in their study. The incubation cabinet were metal-based, while the photobioreactors were acrylic-based.…”