Microelectrodes: Their Use in Microbial Ecology

Abstract

Among the fundamental goals of microbial ecology is the development of methods that will enable the identification and counting of the important microorganisms in nature, the determination of their physical and chemical microenvironment, and the analysis of their metabolic processes and interactions. Due to the small size of the organisms, much effort has been devoted to the development of high-resolution techniques for the observation and understanding of the world of bacteria on a microscale. Scanning and transmission electron microscopy and fluorescent staining, immunofluorescence and other techniques for light microscopy have been the most successful in terms of reaching a high spatial resolution. With respect to our understanding of the microbial microenvironments and of the nature of the microorganisms that carry out the measured metabolic activities, there is still a long way to go. Most chemical and radiotracer techniques in use today operate on a centimeter or at best on a millimeter scale and in most cases their results cannot be directly related to the relevant microorganisms. One notable exception to this is the combined use of autoradiography and fluorescence microscopy on microbial communities.