Application of Ultrasound in Microbial and Algal Biofuel Production

The application of ultrasound has received immense research attentions in the past few years due to its application in various sectors including dye degradation, pretreatment process, fuel production, bioprocessing, etc. Recently, ultrasonication has been used as a novel bioprocessing tool for enhancing biofuel production from microbial and algal biomass during the fermentation process. Additionally, this technique is also used in many areas of downstream processing such as extraction of lipids from biomass, filtration, and crystallization. The usage of ultrasonication during the fermentation process can result in the enhancement of the transfer of oxygen for aerobic culture, homogenization of biomass for the reduction in clump formation, and faster substrate transfer to biomass which further results in enhanced microbial growth. In view of this, the present chapter mainly focuses on the role of ultrasonication in microbial and algal lipid production and its extraction process with an aim for liquid biofuel production. Additionally, the influence of various operating parameters (power intensity, frequency, duration, reactor design, and kinetics) over the growth, lipid production, and extraction process are also described in detail.