Introduction to Bacterial Cellular Engineering The primary goal of synthetic biology is to engineer organisms to perform functions designed by researchers in a reliable, safe, and robust manner. Bacterial synthetic biology is a scientific discipline of synthetic biology that uses engineering and molecular biology tools to synthesize part of or the whole bacteria that do not exist in nature. Bacterial cellular engineering is leading to new approaches for the wide application of bacterial synthetic biology. In recent years, several novel reverse genetics approaches have been developed and increasingly used for strain improvement in this era of synthetic biology. These approaches can be used to introduce mutations into specific genes of interest or to alter the gene expression profiles by conditionally inhibiting mRNA expression at the translation level. Furthermore, some synthetic bacterial cell-cell adhesion tools that can be used to adhere cells into defined morphologies and patterns have also been developed to enable the construction of high-level multicellular designs.