Identity and function of single microbial cells within a community by Raman microspectroscopy and related single-cell techniques

Linking both identity and function within micro- bial communities has long been seen as essential for understanding the role that bacteria play in the environment. Techniques based on the study of single microbial cells offer a unique approach that provides information about heterogeneity within populations, and the role of spatial organisation within the environment. This chapter details some of the prominent single-cell techniques cur- rently in use for the study of microbial ecology, with a particular focus on Raman spectroscopy. A general overview of this technique is provided, with examples of its applicability for studying different features of microbial systems. Special at- tention is given to the use of Raman spectroscopy in combination with fluorescence in situ hybridi- sation (FISH) and stable isotope probing (SIP), which together can be utilized to gain an inSight into the identity and function of Single bacterial cells in situ.