Leather Processing Technology Division, CSIR-Central Leather Research Institute, Adyar, Chennai, 600020, India.
Inorganic and Physical Chemistry Laboratory, CSIR-Central Leather Research Institute, Adyar, Chennai, 600020, India.
Sci Rep. 2020 Dec 17;10(1):22274. doi: 10.1038/s41598-020-79406-8.
Severe water deficit and highly polluting effluent generation from leather industries have constantly been pressurizing the tanners to adopt cleaner leather processing systems. The present study aims to minimize the use of water by substituting it with non-aqueous green solvents and also to enhance the enzyme action in alpha-amylase based fiber opening process. The activity of alpha-amylase in select non-aqueous green solvents namely, heptane, polyethylene glycol 200 and propylene glycol is considerably higher by 62, 38 and 31% than in water, respectively. Comparable results are obtained for the catalytic efficiency of alpha-amylase and hence it is further validated in collagen fiber opening trials as well. Scanning electron micrographs, histological images and proteoglycan estimation supported the above findings at 1% alpha-amylase dosage. The final quality of the experimental leathers in terms of physical and bulk properties is comparable to that of control leathers. Recycling studies indicate that it is possible to replace water with green solvents for enzymatic fiber opening with the feasibility to recover more than 85% solvent-enzyme mixture and reuse without any additional alpha-amylase usage. Reduction in pollution load coupled with the efficient catalytic action of enzyme in non-aqueous media favors the present protocol for industrial applications.
严重的水资源短缺和高污染废水的产生一直给制革行业带来压力，迫使他们采用更清洁的皮革加工系统。本研究旨在通过用非水绿色溶剂替代水来减少用水量，同时提高基于α-淀粉酶的纤维打开过程中的酶活性。在选择的非水绿色溶剂中，正庚烷、聚乙二醇 200 和丙二醇中的α-淀粉酶活性分别比在水中高 62%、38%和 31%。α-淀粉酶的催化效率也得到了类似的结果，因此在胶原蛋白纤维打开试验中也得到了验证。扫描电子显微镜、组织学图像和糖胺聚糖估计支持了在 1%α-淀粉酶剂量下的上述发现。在物理和体积性能方面，实验皮革的最终质量与对照皮革相当。回收研究表明，用绿色溶剂代替水进行酶法纤维打开是可行的，有可能回收 85%以上的溶剂-酶混合物，并在不添加额外α-淀粉酶的情况下重复使用。在非水介质中，污染负荷的减少和酶的高效催化作用有利于本协议在工业中的应用。
