Probing the Biogenesis of Polysaccharide Granules in Algal Cells at Sub-Organellar Resolution via Raman Microscopy with Stable Isotope Labeling
Probing the Biogenesis of Polysaccharide Granules in Algal Cells at Sub-Organellar Resolution via Raman Microscopy with Stable Isotope Labeling
复制标题
通过稳定同位素标记的拉曼显微镜以亚细胞器分辨率探讨藻细胞中多糖颗粒的生物发生
DOI：
10.1021/acs.analchem.1c03216
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发表时间：
2021
影响因子：
7.4
通讯作者：
Hoshino Yu
中科院分区：
文献类型：
--
作者：
Yonamine Yusuke;Asai Takuya;Suzuki Yuta;Ito Takuro;Ozeki Yasuyuki;Hoshino Yu
光养生物将二氧化碳同化成有机化合物，并在储存细胞器中积累。研究贮藏细胞器的碳动力学可以提高有价化合物的生产效率，有利于筛选具有高光合活性的菌株。为了全面阐明这些细胞器的碳动力学，需要探索在特定时间段积累的碳原子在细胞器内的分布。在本研究中，采用稳定同位素（13C）作为跟踪探针，通过受激拉曼散射（SRS）显微镜对多糖在储存细胞器中的生物合成进行了时空探测。研究了单细胞光合藻类叶绿藻（Euglena gracilis）中积累的β-1,3-葡聚糖储存细胞器Paramylon granules的模式细胞器。在生产酰胺颗粒的过程中，将培养基碳源由nah12co3转换为nah13co3；这导致颗粒中12c和13c成分的分布，从而可以跟踪生物合成过程。利用高分辨率SRS成像和标签切换技术，可以三维可视化单个paramylon颗粒内12c和13c成分的定位，从而揭示paramylon颗粒的生长过程。我们认为该方法可用于全面阐明贮藏细胞器的动态活性。
Phototrophs assimilate CO2into organic compounds that accumulate in storage organelles. Elucidation of the carbon dynamics of storage organelles could enhance the production efficiency of valuable compounds and facilitate the screening of strains with high photosynthetic activity. To comprehensively elucidate the carbon dynamics of these organelles, the intraorganellar distribution of the carbon atoms that accumulate at specific time periods should be probed. In this study, the biosynthesis of polysaccharides in storage organelles was spatiotemporally probed via stimulated Raman scattering (SRS) microscopy using a stable isotope (13C) as the tracking probe. Paramylon granules (a storage organelle of β-1,3-glucan) accumulated in a unicellular photosynthetic alga,Euglena gracilis, were investigated as a model organelle. The carbon source of the culture medium was switched from NaH12CO3to NaH13CO3during the production of the paramylon granules; this resulted in the distribution of the12C and13C constituents in the granules, so that the biosynthetic process could be tracked. Taking advantage of high-resolution SRS imaging and label switching, the localization of the12C and13C constituents inside a single paramylon granule could be visualized in three dimensions, thus revealing the growth process of paramylon granules. We propose that this method can be used for comprehensive elucidation of the dynamic activities of storage organelles.