The area of biocatalysis has been experiencing tremendous growth from its early foundations to its present state of the art and science. Cross‐inspiration and interconnections between the art and know‐how of different practical biocatalytic applications and the motivation for the creation of fundamental knowledge in the science of biocatalysis over time made problem‐solving feasible to successfully and efficiently eliminate the associated bottlenecks. As building bridges across different cultures, disciplines, and interests has been a key success factor of past achievements, the current situation shows that this holds even more today. The current megatrends have intensified the need for providing system‐relevant products, for considering resource‐efficient and sustainable processes, and for providing resilient and robust supply chains. Boundary conditions such as resource limitations, safety, health, environment, and sustainability issues have become important drivers for innovation in science, industry, and society. Thereby, the science of biocatalysis is essential for creating new transformations and building new sustainable value chains on a global scale, although the focus is, on a different scale, addressing the molecular and engineering aspects of biocatalysis. Research, development, and innovation of biocatalysts in the form of whole cells, cell‐free extracts, or isolated enzymes, their characterization, optimization, and engineering for desired transformation, as well as reaction and process engineering are key for enabling viable biocatalytic processes at scale. The design of biocatalytic reactions now covers a broadening research area which extends from one‐step and multistep biocatalytic reactions to total biocatalytic syntheses based on cheap and readily available renewable resources such as glucose and even CO₂. The coupling of reactions and reactors is a very dynamic and inspiring field and includes research focusing on cascade reactions, artificial metabolic pathways, and systems biocatalysis and thus is bridging over to metabolic engineering, systems biology, and synthetic biology. On the other hand, synthetic methodologies of biocatalysis are also very well suited to interlink the scientific disciplines biotechnology and chemistry, as it is exemplified by the development of novel chemoenzymatic synthetic methodologies at the interface of biocatalysis and organic chemistry. The molecular economy and ecoefficiency perspectives of biocatalytic transformation toolboxes connect biocatalysis to the concepts of a circular economy and bioeconomy, and thereby to engineering and social sciences.

The large growth of knowledge in biocatalysis worldwide and its facilitated global communication provides excellent opportunities for addressing present and future bottlenecks and challenges. This Special Issue reflects some of the encouraging new approaches and developments to biocatalysis. For this purpose, authors from the most recent BioTrans Symposium and the European Congress of Applied Biotechnology (ECAB) have been invited to contribute their work. The different articles aim to highlight advances from different molecular and engineering research areas, thereby illustrating the integrative character of biocatalysis research.

This Special Issue includes research articles, rapid communications, and reviews on topics ranging from molecular biology and microbiology aspects of whole‐cell biocatalysis, discovery and characterization of novel enzymes, enzyme engineering, secretion and immobilization, reaction engineering, photobiotechnology, enzyme downstream processing and purification to novel and optimized biocatalytic and chemoenzymatic reactions and cascades.

We thank very much all the experts who have contributed their most recent work to this Special Issue on Biocatalysis.

从其早期的基础发展到目前的技术水平，生物催化领域一直在经历着巨大的发展。随着时间的推移，不同的实际生物催化应用领域的技术与知识之间的相互启发和相互联系，以及随着时间的推移在生物催化科学领域创建基础知识的动机，使问题解决成为可能，从而成功，有效地消除了相关瓶颈。建立跨不同文化，学科和兴趣的桥梁已成为过去成就的关键成功因素，目前的情况表明，这种情况在今天尤为重要。当前的大趋势加剧了对提供与系统相关的产品，考虑资源高效和可持续流程以及提供弹性和健壮的供应链的需求。资源限制，安全，健康，环境和可持续性问题等边界条件已成为科学，工业和社会创新的重要驱动力。因此，生物催化科学对于在全球范围内进行新的转型和建立新的可持续价值链至关重要，尽管重点是在不同规模上解决生物催化的分子和工程方面。以全细胞，无细胞提取物或分离的酶形式进行生物催化剂的研究，开发和创新，其表征，优化和工程化以实现所需的转化，以及反应和工艺工程，对于实现可行的生物催化工艺至关重要规模。₂。反应和反应器的耦合是一个非常活跃和鼓舞人心的领域，包括侧重于级联反应，人工代谢途径和系统生物催化的研究，因此正延伸到代谢工程，系统生物学和合成生物学。另一方面，生物催化的合成方法学也非常适合于将科学学科的生物技术和化学联系起来，因为在生物催化和有机化学的界面上新型化学酶法合成方法的发展就证明了这一点。生物催化转化工具箱的分子经济和生态效率观点将生物催化与循环经济和生物经济的概念联系起来，从而与工程和社会科学联系起来。

全球生物催化知识的大量增长及其便利的全球交流为解决当前和未来的瓶颈和挑战提供了绝佳的机会。本期专刊反映了一些令人鼓舞的生物催化新方法和新进展。为此，最近的BioTrans研讨会和欧洲应用生物技术大会（ECAB）的作者均应邀为他们的工作做出贡献。不同的文章旨在强调来自不同分子和工程研究领域的进展，从而说明生物催化研究的综合特征。

本期特刊包括研究文章，快速交流以及对以下主题的评论，这些主题包括全细胞生物催化的分子生物学和微生物学，新型酶的发现和表征，酶工程，分泌和固定化，反应工程，光生物技术，酶下游加工和纯化，以优化和优化新型的生物催化和化学酶反应和级联反应。

我们非常感谢为《生物催化专刊》贡献最新成果的所有专家。