Establishment of ultrasonic stimulation to enhance growth of Haematococcus lacustris. (September 2022)

• Record Type: Journal Article
• Authors: Han, Sang-Il; Jeon, Min Seo; Ahn, Joon-Woo; Choi, Yoon-E
• Is Part Of: Bioresource technology. Volume 360(2022)
• Publication Date: 2022-09
• Subjects: Haematococcus lacustris -- Astaxanthin -- Ultrasonication -- Cell division; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2022.127525
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Haematococcus sp. is a promising source of natural astaxanthin for commercial use. To improve the productivity of H. lacustris, ultrasonic stimulation was adopted. Ultrasonic stimulation enhanced the growth and chlorophyll content of H. lacustris . Sonication caused tiny cracks on the cell wall and improved nutrient transport. After sonication, mRNA levels of minD and transporter were significantly increased. Abstract: In this study, ultrasonication at a frequency of 40 kHz was used to shorten the sonication period and enhance the growth of Haematococcus lacustris . To confirm the optimal conditions, the effects of ultrasound output and treatment interval were examined. Under optimal conditions (20 W and 15-day cycle), the maximum cell density and chlorophyll content were 66.75 × 10 4 cells mL −1 and 36.54 mg g −1, respectively, which were increased by 50.00% and 39.01%, respectively, compared to the control. Transmission electron microscopy analysis showed that ultrasonication caused tiny cracks in the W4 and W6 strata but did not disrupt the inner W2 layer. Additionally, RT-qPCR analysis showed that ultrasonication upregulated both cell division and nitrogen uptake. No difference were detected in the composition or quantity of fatty acids. This study demonstrates a novel ultrasonic approach for enhancing the growth of H. lacustris .