The quest for the minimal bacterial genome

The onset of techniques for both editing extant bacterial chromosomes and synthesizing long DNA sequences has enabled addressing the question on the smallest set of genes and biological functions that are required for running an operative cell. But this is not only a fundamental scientific endeavour: simpler genomes could be easier to understand and eventually reprogram for the sake of diverse applications. This has fostered efforts to eliminate apparently useless if not annoying DNA segments from many biotechnologically relevant strains as well as attempts to (re)write complete genomes a la carte. Yet, the smallest number of genes that enable given functionalities do vary depending on the ultimate agenda, as both natural and engineered small-size genomes afford genetic simplicity by engaging in a suite of complex interactions with the surrounding medium.