Enzyme sources in wastewater treatment: Their influence on enzymatic bioremediation and large-scale applications

• Enzyme sources are significant to enzymatic wastewater treatment. • Five enzyme sources with distinct characteristics are applicable in sewage treatment. • Typical wastewater treatment enzymes vary in mechanisms, applications, and sources. • Enzyme sources producing cost-effective, high-activity enzymes are key to scale-up. Enzymes have recently garnered increased attention in wastewater treatment, and enzyme sources are critical for enzymatic applications, influencing enzyme types, abilities, production strategies, costs, large-scale applications, and other factors. However, existing studies on enzyme sources for wastewater treatment are fragmented, often concentrating on specific enzyme sources or their applications rather than offering a comprehensive overview. Additionally, research on scaling up enzymatic wastewater treatment remains limited. This study addresses these gaps by providing a comprehensive analysis of enzyme sources and their feasibility in wastewater treatment. Enzymatic wastewater treatment primarily relies on enzymes derived from animals, plants, microorganisms, organic waste, and synthetic sources, each offering distinct advantages and limitations. Commonly used enzymes in sewage bioremediation include lipases, proteases, laccases, peroxidases, glucose oxidases, and nanozymes, each with specific functional mechanisms, applications, and origins. While commercial enzymes are available from various sources, high costs and stability issues remain significant barriers to large-scale application. To address these challenges, this study establishes key criteria for scale-up and evaluates the feasibility of different enzyme sources in large-scale applications. Finally, perspectives on the challenges of enzymes in wastewater treatment regarding enzyme sources and future research directions are proposed to facilitate the industrial applications of enzymatic wastewater treatment.