Enhanced biomass and lipid accumulation of mixotrophic microalgae by using low-strength ultrasonic stimulation. (January 2019)

• Record Type: Journal Article
• Authors: Ren, Hong-Yu; Xiao, Ruo-Nan; Kong, Fanying; Zhao, Lei; Xing, Defeng; Ma, Jun; Ren, Nan-Qi; Liu, Bing-Feng
• Is Part Of: Bioresource technology. Volume 272(2019)
• Page Start: 606
• Page End: 610
• Publication Date: 2019-01
• Subjects: Algal culture -- Biomass -- Lipid accumulation -- Mixotrophic mode -- Ultrasonic stimulation; 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.2018.10.058
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Ultrasonic irradiation markedly enhanced the algal biomass and lipid accumulation. The optimal ultrasonic treatment parameters for lipid production were obtained. Low-strength ultrasonic stimulation did not damage the integrity of cell structure. The biomass concentration and lipid content of microalgae increased 26.9% and 37%. Abstract: Ultrasonic treatment was applied to enhance the biomass and lipid accumulation of mixotrophic microalgae. The optimal microalgal ultrasonic power, ultrasonic frequency, ultrasonic interval and growth phase were 20 W, 20 Hz, 2 s and logarithmic phase, respectively. The maximum biomass concentration and lipid content reached 2.78 g L −1 and 28.5%, which were 26.9% and 37% higher than those of the control group. Microscope analysis shows that ultrasonic exposure caused tiny cracks or holes on the surface of cell walls, but did not damage the integrity of algal cell structure. After ultrasonic stimulation, the permeability of membrane and the transport of nutrients were improved, and the utilization rate of substrate and pigment concentration increased 22.7% and 18.4%, respectively. However, excessive ultrasonic irradiation significantly inhibited the cell growth and lipid accumulation of microalgae. This study indicates the feasibility and efficiency of using low-strength ultrasound in promoting biomass and lipid production of microalgae.