Enhancement of lipid productivity with a novel two-stage heterotrophic fed-batch culture of Chlorella protothecoides and a trial of CO2 recycling by coupling with autotrophic process. (December 2016)

• Record Type: Journal Article
• Authors: Wang, Tao; Tian, Xiwei; Liu, Tingting; Wang, Zejian; Guan, Wenyan; Guo, Meijin; Chu, Ju; Zhuang, Yingping
• Is Part Of: Biomass and bioenergy. Volume 95(2016:Dec.)
• Page Start: 235
• Page End: 243
• Publication Date: 2016-12
• Subjects: Microalgae -- Chlorella protothecoides -- Lipid -- Two-stage oxygen supply -- Fed-batch culture -- Dual-mode culture; Biomass energy -- Periodicals; Biomass -- Periodicals; Energy-Generating Resources -- Periodicals; Bioénergie -- Périodiques; 333.9539
• DOI: 10.1016/j.biombioe.2016.10.010
• Languages: English
• ISSNs: 0961-9534

Abstract

Abstract: In this study, the influences of oxygen supply and nitrogen starvation on cell growth and lipid production by heterotrophic culture of Chlorella protothecoides were investigated in a 5-L stirred-tank bioreactor. The results demonstrated that both a low oxygen supply and nitrogen starvation are favorable for lipid accumulation, but limit cell growth and may therefore reduce the overall lipid production. Hence, a novel two-stage strategy for oxygen supply and nitrogen starvation was proposed in a batch culture, increasing the lipid content and yield on glucose by a factor 2.14 and 2.03 compared to the one-stage batch culture with high oxygen supply and sufficient nitrogen availability, respectively. Applying the two-stage process in a fed-batch culture further increased the lipid productivity to 175.2 mg/(L·h), giving a lipid yield of 195.6 mg/g. Furthermore, a dual-mode culture, coupling a heterotrophic process with autotrophic process, was implemented to allow for CO2 recycling. This improved the lipid productivity and carbon utilization efficiency, further contributing towards cost-effective and environment-friendly algal lipid production. Highlights: Oxygen supply plays a significant role in cell metabolisms. Low oxygen supply and nitrogen starvation benefit lipid accumulation. Two-stage heterotrophic fed-batch culture enhanced the lipid yield and productivity. The dual-mode culture strategy drove a high efficiency lipid production.