Effects of light intensity and photoperiod on pigments production and corresponding key gene expression of Rhodopseudomonas palustris in a photobioreactor system. (December 2019)

• Record Type: Journal Article
• Authors: Liu, Shuli; Daigger, Glen T.; Kang, Jia; Zhang, Guangming
• Is Part Of: Bioresource technology. Volume 294(2019)
• Publication Date: 2019-12
• Subjects: Light intensity -- Light/dark cycle -- Biomass -- Pigments -- Gene expression; 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.2019.122172
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Carotenoids and bacteriochlorophyll yields displayed good synergistic effect. Carotenoids and bacteriochlorophyll yields were optimal at light/dark cycle of 4/2. Light/dark cycle had impact on crtA and bchE genes expressions. The crtA gene expression is consistent with bchE genes expression. Abstract: Light intensity and photoperiod significantly affect Rhodopseudomonas palustris growth and pigments production and their optimization is necessary for pigment biosynthesis. In this study, the impacts of different light intensity and light/dark cycles were investigated on biomass, carotenoids, bacteriochlorophyll production, together with pollutant removal, in a photobioreactor system. Results showed that R. palustris had the highest carotenoids and bacteriochlorophyll productions with light intensity of 150 μmol-photons/m 2 /s and light/dark cycle of 4/2 (16 h/8h). The corresponding values were 1.94 mg/g-biomass and 1.17 mg/g-biomass, respectively. The effects of light/dark cycle on crtA and bchE gene expression in pigments biosynthesis were also studied. Mechanism analysis revealed that carotenoids and bacteriochlorophyll yields represented good synergistic effect, which was consistent with the up-regulation of crtA and bchE gene expressions under optimal light/dark cycle of 4/2.