The Microbial Biodiversity Advanced Research Training Course at the Marine Biological Laboratory (MBL) is a highly regarded, intensive six-week experience. For over 50 years, it has been instrumental in training generations of early career researchers in the field of advanced microbial sciences. The primary objective of the program is to equip students with the modern experimental skills necessary to investigate microbiological questions across various biological scales, ranging from the study of single microbial cells, populations, or ecosystems. The Microbial Biodiversity course is dedicated to cultivating the next generation of microbial scientists in modern experimental techniques and interdisciplinary approaches to understand and predict the function of microbial communities in ecosystems health and the impact of microbiota on the planet. This training prepares students to contribute to a variety of research careers, including those in the biotechnology sector and life sciences medicine. The course investigates microbial biodiversity in rich natural freshwater and intertidal ecosystems including a) Trunk River, a brackish intertidal inlet; b) the Great Sippewissett Salt Marsh; c) the acidic, freshwater Cedar Swamp; and d) the School Street Marsh, a phototrophic and iron- oxidizing layered community. Students isolate collections and develop genomic in-house datasets that are made publicly available for current and future courses to delve into evolutionary and ecologic