Increasing lipid production of Desmodesmus sp. through atmospheric and room temperature plasma orientated with malonic acid: Performance and biochemical mechanism. (15th March 2022)

• Record Type: Journal Article
• Authors: Sun, Xin; Meng, Lingshun; Li, Pengfei; Su, Zhiyuan; Wang, Xiaorong; Lian, Yichen; Liu, Zhe
• Is Part Of: Journal of cleaner production. Volume 342(2022)
• Publication Date: 2022-03-15
• Subjects: Desmodesmus sp. -- Atmospheric and room temperature plasma -- Malonic acid -- Triglyceride -- Enzyme activity -- Gene expression; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2022.130911
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Desmodesmus sp. strain b15 with a high lipid yield was obtained through atmospheric and room temperature plasma (ARTP) mutagenesis orientated by malonic acid (MA) resistance screening. Key enzyme activity and gene expression were measured to elucidate the biochemical mechanisms regulating the high lipid synthesis of the mutant algal strains. MA further significantly enhanced the screening efficiency of the targeted lipid-rich algal strains mutated by ARTP, where the number of potential target algal strains was 3.5 times higher than the mutant strains by single ARTP. The triglyceride and total lipid content of strain b15 reached 330.21 and 373.27 mg L −1, which were 48.98% and 114.99% higher than the mutant a17 strain from single ARTP and the control strain, respectively. The maximum quantum yield (Fv/Fm) and relative electron transport rate (ETR) for the photosynthetic activity of b15 were lower than the control group. Additionally, the activities of acetyl-CoA carboxylase (ACCase) and diacylglycerol acyltransferase (DGAT) related to triglyceride synthesis were higher in b15, but malate dehydrogenase (MDH) and succinate dehydrogenase (SDH) were greatly inhibited in the tricarboxylic acid cycle (TCA) by MA. The expressions of key regulatory genes of accD and dgat7566 for lipid synthesis in mutant b15 were also significantly higher than those in a17 and the control group (P < 0.05), and the decreased expression of SDH2 in the TCA also verified the superior lipid synthesis performance of strain b15. Highlights: Malonic acid resistance screening significantly improved the screening efficiency. Triglyceride content of strain b15 was greatly enhanced but with hindered biomass. Lipid yield of strain b15 was higher by 96.68% than that of the original strain. Enzyme activities and gene expressions for lipid synthesis of b15 greatly increased. Enzyme activities and gene expression of TCA cycle in b15 distinctively inhibited.