Catalysis plays an important role in human civilization and economic development.Every breakthrough related to the field of catalysis has great impact on our everyday lives.To achieve harmonious development between human and nature through developing chemical processes with environmental friendliness and atom economy,the improvement and innovation of catalytic systems have drawn great attention.Biocatalysis is the engine of life from the very beginning,which is the example that we always learn from,mimic,and aim to surpass in scientific research and industrial development.The goal of the development of biocatalysis technology is to make our industrial manufacturing go under mild conditions as nature does.However,the current situation of biocatalysis application is still far from the ultimate aim,providing countless opportunities for further development.Biocatalysis includes whole-cell and enzymatic catalysis,with three major challenges to be addressed:1) construction of biocatalysts (including cells and enzymes),creating biocatalysts with high activity and selectivity effectively;2)engineering of biocatalysts,allowing biocatalysts act under industrial conditions efficiently;3)application of biocatalysts,integrating biocatalysis into the existing industrial manufacturing processes smoothly.With the development of biological science and technology,our ability of constructing enzymes and cells on demand in laboratory has improved significantly.On the contrary,the types of biocatalysts and biocatalytic processes utilized in industry are still limited.Much effort is in need to fill the gap between theories and applications.Therefore,based on chemical engineering,biocatalyst engineering is needed to systematically investigate the following issues:large-scale preparation technologies of biocatalysts with high activity,stability,and robustness;construction of in vitro artificial multi-enzyme catalysts;and methods of coupling biocatalysis with chemical catalysis.Especially,coupling biocatalysis with heterogeneous catalysis,homogeneous catalysis,photocatalysis,electrocatalysis and other types of catalysis will realize the processes that cannot be driven by single type of catalysis,greatly expanding the boundary of biocatalysis while improving the utilization efficiency of resources and energy.

This special issue of the Chinese Journal of Chemical Engineering focuses on the development of biocatalysis from the aspect of chemical engineering,including the molecular design of biocatalysts,the chemical or genetic modification of biocatalysts,the study of kinetics and thermodynamics of biocatalytic processes,the design of novel biocatalytic cascade reactions,the development of biocatalyst immobilization,and the scaling up of biocatalytic processes.In this issue,we aim to summarize the recent scientific and technological advances that established biocatalysis as a practical and environmentally friendly way to produce chemicals,pharmaceuticals and materials for human society,which offered many possibilities for the green chemical industry.

Jun GeTsinghua University,ChinaCorresponding author.E-mail address:junge@mail.tsinghua.edu.cn

Huilei YuEast China University of Science and Technology,ChinaE-mail address:huileiyu@ecust.edu.cn