A Review of Potential Enzymes: Protease and Keratinase for Dehairing Process as Cleaner and Eco-Friendly Leather Processing

In recent decades, there has been growing concern and negativity from the environmental impact of industrial development, which produces lots of technological changes. The significant contribution of the leather industry has a good impact on the economic sector; however, it is faced with challenges caused by pollution to the environment. Special attention is required for disposal of solid wastes because of the large amounts that are generated and legal restrictions. Environmental problems are caused by the large amount of wastes originating from chemicals during processing, especially in dehairing process. Conventional dehairing by lime sulfide process causes high chemical oxygen demand emission, biological oxygen demand, and total suspended solids. The dehairing mechanism is vaguely understood at present from the point of view of the enzyme specificity, which is needed for consistent and satisfactory hair removal without deleterious effect on the leather quality. It is known that the use of enzymes has potential as an alternative that can be used to reduce the harm caused by toxic chemicals including for waste management. Recently, there has been increasing research on application of enzymes in various leather production processes. The use of protease and keratinase enzymes in leather processing industry has the most promising potential to improve the surrounding environment. Therefore, this study aimed to review relevant literature in terms of dehairing processes without adverse effects in order to make good quality leather. Further scientific discussion is needed for understanding the gap of these critical issues in this area.