Genome engineering is a collection of scientific methods which allow the precise editing of DNA in a variety of living organisms. Multiplex Automated Genome Engineering (MAGE) is an established method for genome engineering in Escherichia coli allowing mutagenesis of multiple targets in parallel. Three different MAGE adaptations have been characterized, Co-selection MAGE, pORTMAGE and CRMAGE, all focused on improving MAGE efficiency in different conditions where the original MAGE efficiency levels were not satisfactory. The goal of this thesis was to describe and compare the specific MAGE adaptations and their efficiencies to the original MAGE approach, and to select the most suitable approach for testing in/dispensability of tryptophan in E. coli. Based on the comparison, CRMAGE has been selected as the most suitable candidate for use in this project alongside various computational methods, thanks to the specific approach to recombinant cell selection noticeably raising the efficiency of integrating point mutations.