UV-A radiation increases biomass yield by enhancing energy flow and carbon assimilation in the edible cyanobacterium Nostoc sphaeroides

作者：Zhen Chen, Zu-Wen Yuan, Weixin Luo, Xun Wu, Jinlong Pan, Yongqi Yin, Hai-Chen Shao, Kui Xu, Weizhi Li, Yuanliang Hu, Zhe Wang, Kunshan Gao, Xiongwen Chen · 发表于：Applied and Environmental Microbiology · 年份：2024 · DOI：10.1128/aem.02110-23 · 被引用次数：8 · 研究领域：Biocrusts and Microbial Ecology、Algal biology and biofuel production、Photosynthetic Processes and Mechanisms

ABSTRACT Ultraviolet (UV) A radiation (315–400 nm) is the predominant component of solar UV radiation that reaches the Earth’s surface. However, the underlying mechanisms of the positive effects of UV-A on photosynthetic organisms have not yet been elucidated. In this study, we investigated the effects of UV-A radiation on the growth, photosynthetic ability, and metabolome of the edible cyanobacterium Nostoc sphaeroides . Exposures to 5–15 W m −2 (15–46 µmol photons m −2 s −1 ) UV-A and 4.35 W m −2 (20 μmol photons m −2 s −1 ) visible light for 16 days significantly increased the growth rate and biomass production of N. sphaeroides cells by 18%–30% and 15%–56%, respectively, compared to the non-UV-A-acclimated cells. Additionally, the UV-A-acclimated cells exhibited a 1.8-fold increase in the cellular nicotinamide adenine dinucleotide phosphate (NADP) pool with an increase in photosynthetic capacity (58%), photosynthetic efficiency (24%), Q A re-oxidation, photosystem I abundance, and cyclic electron flow (87%), which further led to an increase in light-induced NADPH generation (31%) and ATP content (83%). Moreover, the UV-A-acclimated cells showed a 2.3-fold increase in ribulose-1,5-bisphosphate carboxylase/oxygenase activity, indicating an increase in their carbon-fixing capacity. Gas chromatography–mass spectrometry-based metabolomics further revealed that UV-A radiation upregulated the energy-storing carbon metabolism, as evidenced by the enhanced accumulation of sugars, ...