单细胞拉曼光谱在微生物研究中的应用

Advances in the application of Raman microspectroscopy in microbe research

摘要:

拉曼显微光谱是一种能够提供0.5-1.0 μm空间分辨率的单个微生物细胞内化学结构信息的研究技术。近几年来，拉曼显微光谱被越来越多地应用于微生物单细胞的研究中，它可以快速无损地检测微生物细胞内的特征化学组分。典型的单个微生物细胞的拉曼光谱包含核酸、蛋白质、碳水化合物、脂质和色素（例如类胡萝卜素）等信息，这些信息能够表征微生物细胞的基因型、表型和生理状态。所以单细胞拉曼显微光谱是一种可用于区分微生物样品的“全生物指纹”技术，它可用于研究单个微生物细胞生命阶段的转变、鉴定微生物单细胞中的色素及其他化合物的含量变化等。本文综述了目前拉曼显微光谱在微生物单细胞研究上的应用，主要包括与稳定同位素标记（stable isotope probing，SIP）、拉曼成像、光谱分类和细胞分选技术结合来探究微生物单细胞对物质吸收后特征峰的变化、推导物质循环过程、进行微生物分类鉴定和探索基因型与表型的关系。拉曼显微光谱作为微生物单细胞研究的手段之一，在代谢过程的研究、活细胞分选和细胞对物质的利用上具有广泛的应用前景。

Abstract:

Raman microscopy is a technique that provides information on the chemical structure of materials within a spatial resolution of 0.5 to 1 μm. In recent years, Raman microspectroscopy, which can quickly and non-destructively detect characteristic chemical components in single cells, has been increasingly applied to microbiology. The Raman spectrum of a typical microbial cell contains information on nucleic acids, proteins, carbohydrates, lipids, and pigments (e.g. carotenoids) that characterize the genotype, phenotype, and physiological state of the microbial cells. Therefore, single-cell Raman microscopy is a “full bio-fingerprint” technique that can be used to distinguish different microbes. Raman microspectroscopy can be used to study the transformation of individual microbial cell life stages, identify changes in pigments and other compounds in single microbial cells. This paper reviews the current applications of Raman microspectroscopy on the study of microbiology at single cell level. Its combination with stable isotope probing (SIP), Raman imaging, spectral classification and cell sorting techniques that used to explore the microbial classifications and the relationships between genotypes and phenotypes, were also discussed in this paper. Collectively, Raman microspectroscopy is a promising method in the studies of cell sorting and metabolic analysis at single cell level.