Benign Felt-proofing of Wool Fibers Using a Keratinolytic Thermophilic Alkaline Protease

• Published in: Journal of natural fibers Vol. 19; no. 10; pp. 3697 - 3709
• Main Authors: Ismail, Shaymaa A., Abou Taleb, Marwa, Emran, Mohamed A., Mowafi, Salwa, Hashem, Amal M., El-Sayed, Hosam
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 03.10.2022; Taylor & Francis Ltd; Taylor & Francis Group
• Subjects: Acid dyes; Acid resistance; Alkaline protease; Amino acids; dyeing; Dyes; Enzymatic activity; Enzyme activity; Enzymes; Felting; Fibers; Fourier analysis; Fourier transforms; Infrared analysis; Infrared spectroscopy; Keratinocytes; keratinolytic activity; Mechanical properties; Microorganisms; pH effects; Protease; scales; Scanning electron microscopy; Shrinkage; Tensile properties; thermophilic protease; Wet processing; Wool; 关键词: Wool; 嗜热蛋白酶，keratinolytic activity; 毡层， dyeing染色; 羊毛，thermophilic protease; 规模，felting; 角蛋白溶解活性，scales
• ISSN: 1544-0478; 1544-046X
• DOI: 10.1080/15440478.2020.1848721

Felting shrinkage of wool is a major problem which has negative impacts on its performance attributes. Traditional chemical methods used for shrink-resist finishing are suffering from some drawbacks. Therefore, this work aimed at the utilization of microbial protease in wet processing of wool. The bacterial strain Bacillus licheniformis ALW1 produced 52.1 U/mL enzyme activity that was thermophilic with optimum activity at pH 9. Additionally, the enzyme possessed a keratinolytic activity of 4.1 U/mL, suggesting its applicability in wool processing. Therefore, the effects of different treatment conditions; Viz. concentration of the enzyme, temperature, treatment period and pH on some of the physical and chemical characteristics of wool were studied. The felting shrinkage of wool fibers was determined using the Aachener 3-D felting machine. The influence of the enzymatic modification of wool on its dyeability with anionic dye was assessed. Chemical, physical, and mechanical properties of treated samples were evaluated using amino acid analysis, alkali solubility, Fourier Transform Infrared spectroscopy, whiteness index, and tensile properties. Scanning electron microscopy was applied for the examination of wool fibers' surface. The results proved that the modification of wool fibers with the produced enzyme highly improved their felting resistance and dyeability with acid dye without adverse effects on its inherent properties.