Abstract

The leather industry earns special attention because of its strong potential for foreign exchange earnings and employment generation prospects. This industry has developed enormously over the past decades; since, leather has become a material of choice in the world of fashion. However, this industry, like many others, is facing stringent environmental regulations worldwide, due to vast usage of toxic chemicals and generation of hazardous waste. Leather manufacturing involves conversion of raw skins and hides into leather through a series of mechanical and chemical operations. Processes like pre-tanning and tanning are known to contribute ~ 80–90% of the total pollution load in tanneries. In order to mitigate the hazards caused by toxic chemicals, enzymes have been identified as a practical alternative for use during processing and as well as for waste management. Even though the use of enzymes in the leather industry dates long back mainly because of their activity on proteins and fat, the complete replacement of chemicals by enzymes has yet to be realized. Earlier, enzymes were derived from animal excreta, and later on from the pancreas of cattle. However, currently, the enzymes are almost entirely produced by microbial fermentation. In light of this, the current review presents a holistic view on the effective utilization of enzymes in leather making, mainly during soaking, dehairing, bating and degreasing processes in order to minimize waste generation, and also in the recovery of valuable and saleable by-products. Globally, ~ 7 million tons of salted bovine hides are used every year for leather making. By using enzymes in bio-preparation, around 8 million gigajoules of energy saving and 0.7 million tons of CO₂ savings is estimated to be achieved due to lower processing times and associated energy use. Nevertheless, the search for enzymes for their ultimate application in the leather industry as an eco-friendly alternative continues, since, this process is far safer and more pleasant than the traditional method. The progress made in this field during the past two decades are highlighted and will provide further insight on the scope for utilization of enzymes in this industry. In order to achieve sustainability, clean environment and prevent health hazards, the leather industry ought to adopt the use of eco-friendly alternatives which might primarily depend on research, development and implementation of the potential enzyme technology.

中文翻译：

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酶在皮革加工中的应用

摘要

皮革行业因其巨大的创汇潜力和创造就业机会而备受关注。在过去的几十年中，这个行业取得了巨大的发展。从那时起，皮革已成为时尚界的首选材料。但是，由于有毒化学物质的大量使用和危险废物的产生，该行业像许多其他行业一样，在全球范围内都面临着严格的环境法规。皮革制造涉及通过一系列机械和化学操作将生皮和生皮转变为皮革。众所周知，诸如鞣制和鞣制之类的过程约占制革厂总污染负荷的80–90％。为了减轻有毒化学物质带来的危害，酶已被确认为在加工过程中以及废物管理中的实用替代品。尽管皮革工业中酶的使用可以追溯到很久以前，主要是因为它们对蛋白质和脂肪具有活性，但仍无法实现酶对化学物质的完全替代。以前，酶是从动物排泄物中提取的，后来是从牛的胰腺中提取的。但是，目前，这些酶几乎完全是通过微生物发酵产生的。有鉴于此，本篇综述对皮革制造过程中酶的有效利用提出了整体看法，主要是在浸泡，脱毛，软化和脱脂过程中，以最大程度地减少废物的产生，以及回收有价值和可销售的副产品。产品。在全球范围内 每年大约有700万吨盐腌的牛皮被用于制革。通过在生物制剂中使用酶，可节省约800万亿焦耳的能源和70万吨的二氧化碳由于缩短了处理时间并减少了相关的能源消耗，因此预计可实现_2种节省。尽管如此，仍在继续寻找酶以最终在皮革工业中用作环保替代品，因为这种方法比传统方法更安全，更舒适。过去二十年来在该领域取得的进展将得到重点介绍，并将提供有关该行业中酶利用范围的进一步见解。为了实现可持续性，清洁环境并防止健康危害，皮革行业应采用环保替代品，这可能主要取决于潜在酶技术的研究，开发和实施。