oa Editorial [Hot topic: Molecular Display Technologies-Development and Improvement of Powerful Solutions in Medical, Pharmaceutical, and Sustainable Biotechnology (Guest Editors: Seiji Shibasaki and Mitsuyoshi Ueda)]

Since the development of genetic engineering in the 1970s, various biotechnological tools have been established. These tools, which use gene manipulation techniques, have been used to manufacture biologically active compounds and pharmaceutics; they have also enabled the production of various important molecules whose production by conventional fermentation technology was difficult. Thus, gene manipulation techniques have enhanced the efficiency of bioindustrial processes. This issue focuses on genetic engineering and combinatorial bioengineering-based molecular display technology that is unlike any other biotechnological method—it includes “display”, “diversity”, and “directed selection,” (“3D”), which are new concepts. Smith reported that a foreign protein could be inserted into filamentous phage protein III, resulting in the display of a fusion protein on the virion surface; this was the first report on molecular display technology. After this, several types of display systems using different organisms were developed. Combinatorial technology was introduced to endow diversity on the displayed protein; with this technology, several new previously undiscovered proteins were identified. For directed selection of useful clones with desired function from among the numerous clones generated, advanced and high-throughput devices such as cell sorters, chamber array systems, and high-speed DNA analyzing systems have played important roles. This special issue consists of 6 review articles on biotechnology, particularly molecular display technologies. The authors featured in this issue are pioneers in their respective fields and present rather interesting topics in molecular display technology. We, as biotechnologists, should be aware of the importance of patents related in our laboratory for experiments. No matter how new the theme, it is bound to be related to other published/patented works. Therefore, these authors not only describe their results but also use and cite other published/patented material. In the first article, Stahl et al. report Staphylococcal surface display in combinatorial protein engineering and its applications. Next, Tsumoto and Ui describe a topic on rational ligand design introducing thermodynamic analysis. In the third article, Ye and Geels describe the design and applications of vaccines by using molecular display technology. In the fourth article, Shibasaki and Ueda focus on a yeast molecular display system for bioconversion. In the fifth article, bacterial magnetic particles and its biotechnological applications are introduced by Matsunaga et al. In the final article of this issue, Kondo et al. describe the applications of molecular display technology for biorefineries. As evident, these are all intriguing, inter-related topics on molecular display technologies. Through this special issue, the guest editors hope that all readers of the journal will gain a deep understanding of the usefulness of molecular display technologies in the development of various tools for bioindustrial and biotechnological research. We would like to express our gratitude to all the authors for their dedication and for generously sharing their recent research results and patents. We would also like to thank all the reviewers of the articles published in this issue. We are grateful to Ms. Tayyaba Zaidi of Bentham Science Publishers for her practical advice and encouragement.