The book "Plasmid Segregational Instability in Recombinant E. coli Fermentations" offers a comprehensive examination of the segregational instability of plasmids in genetically modified Escherichia coli bacteria. This instability poses a challenge for the successful production of recombinant products. The study focuses on Escherichia coli C600 galK, which is equipped with the plasmid pBR Eco gap that encodes for the enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Under industrial conditions, detailed mathematical models for batch and continuous fermentations have been developed, taking into account non-ideal conditions such as incomplete mixing and variable plasmid loss probabilities. The effects of macromixing and variable plasmid loss probability on plasmid stability, substrate utilization, and product formation are investigated through the integration of generalized plasmid replication kinetics into an experimentally validated model. This specialized book is aimed at professionals and students in the fields of biotechnology, microbiology, and engineering.