Applying mixotrophy strategy to enhance biomass production and nutrient recovery of Chlorella pyrenoidosa from biogas slurry: An assessment of the mixotrophic synergistic effect. (December 2022)

• Record Type: Journal Article
• Authors: Han, Ting; Han, Xiaotan; Ye, Xiaomei; Xi, Yonglan; Zhang, Yingpeng; Guan, Huibo
• Is Part Of: Bioresource technology. Volume 366(2022)
• Publication Date: 2022-12
• Subjects: Chlorella pyrenoidosa -- Mixotrophic synergistic effect -- Biomass production -- Nutrient recovery -- Biogas slurry; 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.2022.128185
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Five metabolic modes of Chlorella pyrenoidosa in biogas slurry was investigated. Mixotrophy enhanced biomass production and nutrient recovery. A better microalgal photosynthetic property was obtained under mixotrophy. The mixotrophic synergistic effect was explained as the efficient use of energy. Abstract: Using biogas slurry to cultivate microalgae can simultaneously obtain microalgal biomass and allow nutrient recovery. Mixotrophic microalgae are widely recognized for their high biomass accumulation and low light dependence, making it possible to overcome the drawbacks of photoautotrophy. In this study, three complete metabolic modes of photoautotrophy, heterotrophy, mixotrophy and two incomplete metabolic modes with the addition of diuron and rotenone were applied to investigate Chlorella pyrenoidosa growth in biogas slurry. The results showed that the mixotrophic group obtained 1.15 g/L biomass, 30 % starch content, 99.40 % ammonium removal and 81.69 % total phosphorus removal, which were highly promoted compared to the others. The decline in chlorophyll, the simultaneous downregulation of Rubisco and citrate synthase and the increase in the actual quantum yield of PSII under mixotrophy revealed a synergistic effect: the complementation of photophosphorylation and oxidative phosphorylation greatly contributed to maximizing energy metabolism efficiency and minimizing energy dissipation loss.