Host-Mimicking Strategies in DNA Methylation for Improved Bacterial Transformation

In 1928, Griffith [1] reported that soluble substances from virulent pneumococcal cells trans‐ formed non-virulent pneumococcus to virulent forms. This substance has now been demon‐ strated to be DNA [2-4]. This is considered to be the first report on genetic transformation of bacteria by exogenous DNA. Subsequently, natural competence of Bacillus subtilis was re‐ ported in 1958 by Young and Spizizen [5]. They also demonstrated genetic transformation of natural competent B. subtilis cells using exogenous DNA. It was in 1970 that genetic trans‐ formation of Escherichia coli using chemically competent cells was reported [6]. Thus, genetic transformation of common bacterial models was established at an early stage in the develop‐ ment of bacteriology. The alternative view is that bacterial models such as B. subtilis and E. coli have become the mainstay of this field because of high transformation ability. Genetic transformation techniques remain important for studying numerous bacteria and for the ad‐ vancement of bacteriology, biochemistry, applied microbiology, and microbial biotechnolo‐ gy. Moreover, recent developments in the search for new bacteria and genome sequencing have provided numerous effective bacteria that are useful for biological studies and indus‐ trial applications. With these developments, there is a greater demand for establishing ge‐ netic transformation methods for more bacteria.