应用红外光谱显微成像技术观测单细胞雨生红球藻虾青素代谢过程

Astaxanthin Metabolic Process in Unicellular Green Alga Haematococcus pluvialis Observed through Infrared Microspectroscopy and Imaging

雨生红球藻是一种适于生产虾青素的单细胞绿藻,虽然已有研究报道了藻细胞内类胡萝卜素的合成代谢途径,但是对类胡萝卜素及虾青素的具体形成过程以及它们在显微尺度上的含量和分布变化还缺乏直接的观测数据和证据。本研究运用高空间分辨率的傅里叶变换红外光谱显微成像技术,对不同时期的单一雨生红球藻细胞中的类胡萝卜素的空间分布和含量进行了观测,根据红外光谱成像数据证实了β胡萝卜素为虾青素合成的前体,并且分析和探讨了细胞中的脂质和蛋白质与虾青素合成及积累的关系。

Haematococcus pluvialis is a potent unicellular green microalga for biotechnological production of astaxanthin and the pathway of carotenoid synthesis has been studied.However,there is still a lack of direct evidence for the detailed process for the sythesis of astaxanthin,especially at the algal cellular level on the micrometer scale.In this work,Fourier-transform infrared（FTIR）microspectroscopy and imaging with high spatial resolution was employed to observe the carotenoid contents and its localizations in single cells of Haematococlus pluvialis in various stages of the life cycle.The microspectroscopic and chemical mapping data confirmed thatβ-carotene is a precursor for astaxanthin,and both lipids and proteins are involved in the sythesis or accumulation of astaxanthin in the cytoplasm.