Microbial trans‐glutaminase enhances the physical and mechanical properties of depigmented wool

Abstract

This study investigates the effects of enzymatic treatment with microbial transglutaminase (m-TGase) on the physical and mechanical properties of the depigmented wool yarns. Coarse pigmented wool yarns were treated with iron (II) followed by depigmentation with both oxidative and oxidative-reductive chemicals. The depigmented wool yarns were then treated with m-TGase to reduce the negative effects of the harsh chemicals. Diverse features of the wool yarns, including: tensile strength, elongation, color, diameter, moisture content, alkali solubility, and weight reduction, were measured before and after bleaching and enzymatic treatments. The treatment with the oxidative and reductive agents led to reduced tensile strength and elongation, and increased lightness, alkali solubility, and moisture content of the yarns. In contrast, the enzymatic treatment by m-TGases cross-linked the proteins of wool fibers via reaction between glutamine and lysine isodipeptide remediated the wool yarns. This improved the tensile strength and elongation and decreased the alkali solubility and moisture content. Fourier transform infrared spectroscopy (FTIR) was used to follow the chemical changes in wool fibres during depigmentation and enzymatic treatments.

Surface functionalization of wool via microbial-transglutaminase and bentonite as bio-nano-mordant to achieve multi objective wool and improve dyeability with madder

“…The wool treated with bentonite and enzyme has the characteristic peaks in the spectrum as a consequence of their presence. However, a decrease in the peak intensity as well as shifting to the lower wavelength corresponded to the N–H (at 3300–3600 cm −1 ) [ 49 ]. In details, amide band, arising from N–H stretching vibration coupled with –OH groups via hydrogen bonding [ 50 ], was observed at wave numbers of 3270 and 3260 cm −1 for the wool sample treated with m-TGase and m-TGase/bentonite, respectively.…”

“…It is well-known that m-TGase is a unique enzyme capable of catalyzing acyl transfer reactions by introducing covalent cross-links between glutamine and lysine in proteins and peptides [ 49 , 54 , 55 ]. Amino acids or alkyl ammonium ions act as a compatibilizing agents to treat clay structures since they exchange easily with ions between the silicates layers of clay [ 56 ].…”

Surface Functionalization of Wool via Microbial-Transglutaminase as Bio-Mordant to Improve Dyeability with Madder in the Presence of Alum

“…The surface changes of wool fibers treated with various concentrations of m-TGase and alum were investigated, and the SEM images are presented in Figure 2a-c. Our results showed that by increasing m-TGase concentration, some surface damages appeared so that some of the scales were damaged and led to less cuticle surface ( Figure 2b). This phenomenon probably was because of alkali condition, which is obtained as a result of more cross-link reaction by adding more m-TGase [43]. Indeed, m-TGase affected wool fiber by following cross-link reaction between glutamine and lysine, which are present in wool structure: Therefore, it is essential to use the enzyme in a suitable amount.…”

“…Since wool fibers are protein-rich fibers, m-TGase could be used to alter the characteristics of wool keratin [29,30,[43][44][45]. 4.…”

Enzymatic processing of protein-based fibers

“…The properties of wool fabrics modified by transglutaminases are summarized in Table S4. Transglutaminase treatment showed the ability to recover tensile strength after previous chemical or protease treatments (Cortez et al 2005;Cardamone 2007;Du et al 2007;Gaffar-Hossain et al 2008;Ge et al 2009;Zhang et al 2010;Montazer et al 2011Montazer et al , 2012. Other effects include (Cui et al 2008).…”