Preface

Biocatalysis—the use of enzymes for chemical transformations—has a long history in providing mankind with all sorts of molecules. While early processes almost exclusively relied on naturally occurring whole-cell systems, the implementation of molecular biology-based methods has rendered the manipulation of isolated enzymes routine work. This in turn has led to improved knowledge about enzymatic mechanisms and boosted enzyme-orientated research in multiple areas. The past years have seen impressive advances leading to sophisticated tools and innovative techniques for the design and development of bio-based processes for the production of (fine) chemicals. The synergy between synthetic biology and biocatalysis is now strongly emerging as an important trend for future sustainable processes and we felt the need to merge these two complementary branches, which have been evolving mainly concurrently.

Excellent books are available for chemists wishing to implement natural catalysts in synthetic processes, while recent books on synthetic biology focus on bottom-up creation of new modular parts, circuit design, and chassis engineering but are not enzyme centric. Specialized and focused reviews in prominent journals on the development of robust and efficient biosynthetic routes are becoming more frequent, but a unifying platform was still missing. This book includes a number of contributions to document the current merging of traditional biocatalysis with more synthetic biology-based approaches, and keeps enzymes as the central protagonists.

The book is organized into five sections. In Section I, Accessing New Enzymes, several contributions exemplify the technical diversity at hand to identify new enzymes, which largely benefits from ever-improving computational power. In Section II, Understanding and Engineering Enzymes, we gathered experts to highlight how modifying protein sequence and structure in silico and in vivo is fundamental to obtaining crucial catalytic insights used to tailor enzyme properties. In Section III, Enzymes from Secondary Metabolism, several contributions highlight the remarkable ability of enzymes in secondary metabolism to construct complex natural products from simple small molecule building blocks. Approaches to engineer and optimize these pathways are also described. Section IV, Biocatalysis for Modern Synthesis, focuses on elaborate enzyme-based processes developed for the synthesis of fine chemicals. Importantly, multi-step reactions now combine various types of (bio)catalysts and are particularly well suited for the cost-effective generation of enantiopure molecules of high value. Finally, Section V, Applied Biocatalysis, reflects the technological input required to implement natural or engineered enzymes in industrial settings, and finishes with an opening on the promising use of enzymes in remediation, according to which biodegradation processes might witness a restored interest.

We hope that readers will find this book helpful to connect all areas that biocatalysis—and synthetic biology—as progressive field now encompasses, and to identify current and emerging trends towards the development of efficient synthetic biological systems in a broad sense.

We thereby hope to trigger mutual inspiration for the currently unfolding generation of hybrid chemists/biologists who are committed to render current and upcoming synthetic processes more sustainable.

Tools exist, let's use them!

Mélanie Hall (Graz, Austria)

Gavin Williams (Raleigh, USA)