Status and trends of enzyme cocktails for efficient and ecological production in the pulp and paper industry

The pulp and paper industry (PPI) is one of the main pillars of the global economy, but its high energy consumption, pollution, and emissions necessitate urgent transformation. Various types of enzymes can play a crucial role in improving pulp performance, reducing energy consumption, as well as decreasing pollution, which benefits a lot to clean and sustainable development. Due to the complex and numerous substrates in the papermaking processes, enzyme cocktails are often more effective single enzymes. In addition, the effect of enzyme cocktails is affected to varying degrees by the complex environment, including the different papermaking process, pH, temperature, residence time, chemical additives and auxiliary technologies. In this review, we provide a brief summary of hydrolases and oxidases frequently applyed in PPI, along with a list of auxiliary enzymes and proteins with potential applications in this field. More attention is given to enzyme cocktails for various processes such as pulping, refining/beating, deinking, bleaching, and stickies control. The factors influencing enzyme efficiency are analyzed and progresses in this area are reviewed. Further, cutting-edge biotechnologies are highlighted to improve the robustness of enzymes, which could expand the market share of enzyme preparations. By and large, studying the mechanisms and influencing factors of enzyme cocktails will facilitate the transition of the PPI to a greener, low-carbon, economical and energy-efficient industry.