Microorganisms precede human existence, they allow for human existence and will most likely transcend it. What do microorganisms mean to us? Researched almost exclusively by the life sciences, microorganisms as a concept, like most others, is constructed and evolving. This thesis looks at the transforming and overlapping understanding of microorganisms as pathogens or enemies, as tools or instruments, as allies in the microbiome and as agents of a microbial planet.

Microorganisms are first followed in Natural History museums because, in them, concepts are turned into matter and experience in a comparable way in which knowledge can be embodied in art and biology. The focus then is on the art forms that explore and participate in constituting what microorganisms mean. Because of their scale, microbes always require the mediation of technologies of display, becoming a phenomenon of mutually constituting meaning and matter. Some of the technologies covered include the Petri dish, Winogradsky columns, Microbial fuel cells and kombucha SCOBY as a material. A selection of artists working with microorganisms is reviewed and the central case studies are the work of Interspecifics of Gilberto Esparza. These works of art and biology are interpreted as a form of artistic practice as research, participating in the microbial posthuman turn, which participates of a greater tradition of posthuman feminisms.

The microbial posthuman implies an epistemological transformation, that is slowly taking place towards post-anthropocentric positions, it an expanded understanding of life, a (micro)biopolitics where the lives that matter start at the microscopic. This expansion of the life that counts has consequences on our understanding of the distribution of life, death and pain for all other species. The microbial posthuman also has implications of a turn from individuality to the community, hybridity, symbiosis and entanglement. Following the posthuman of Rosi Braidotti, the cartographies of this (micro) biopolitics can mean a turn in the ethics of sustainability and environmental, political positioning, and a microbial epistemological turn toward the posthuman.