<p>By looking at the study of microbial metabolism in a molecular biology laboratory, this paper aims to explore how the agency attributed to microbes is built into scientific practice and discourse. I mobilize the word <i>eccentric</i> to unpack the creative, ingenious, and unconventional nature that is assumed of microbes. Because of their expected and yet always surprising chemical capabilities, microbes are understood not only as potentially dangerous pathogens, but also as instrumental in fixing the anthropogenic problems to which humans are struggling to find a solution. The paper then moves on to examine the strategic use of microbial potentialities at the interface between the bio- and the geo- and how this recasts human–microbial relations: the anthropos, finding themselves incapable of facing epochal problems, discover their dependency on other entities, but remain a measure of the extent to which a state of affairs is problematic and in need of repair. I call this partial displacement of the anthropos from the microbiologists’ cosmos “anthropo<i>ec</i>centrism” and invite a reflection on the way that the study of microbial metabolism substantiates and redistributes power and agency across scales.</p>