- Publisher Summary This chapter focuses on the bacteriocins produced by E. coli— namely, colicins and microcins and explores their potential role in agriculture, bioaugmentation, and human health. Colicins and microcins are the primary defense systems found in Escherichia coli . The antimicrobial properties of microcins and colicins make them excellent candidates for application in human and veterinary medicine. The chapter particularly focuses on the colicins and microcins that specifically kill human and animal pathogens, thereby illustrating the potential of these compounds to serve as the next generation of antibiotics. Microcins can also be useful indicators of pathogen presence in poultry. The chapter also provides an overview of novel uses and new antibiotics generated form colcins and microcins. Some colicins and microcins toxins can induce apoptosis and some share common features with apoptosis-induced proteins. As a result they have the potential of becoming an attractive tool to understand apoptosis and might be utilized as cell targeted drugs. Finally, this abundant and diverse family of toxins has the real potential of becoming the next generation of pharmaceuticals.