School of Chemistry, University of Lincoln, Lincoln, LN6 7TS, UK.
School of Life Sciences, University of Lincoln, Lincoln, LN6 7TS, UK.
Appl Microbiol Biotechnol. 2020 Jun;104(12):5361-5370. doi: 10.1007/s00253-020-10625-9. Epub 2020 Apr 22.
Glues based on starch are widely used for the consolidation of brittle fibres in historic and archaeological textiles. Ageing fabrics are affected by hydrolysis/oxidation and cross-linking of these glues, a decrease of glues' solubility, the formation of cracks, and discoloration. The hydrolytic action of enzymes on starch-based glues is promising, as molecular recognition offers great selectivity. However, a systematic assessment of the best methods for applying enzymatic formulations has not been explored yet. Here, α-amylase was applied either by pipetting a solution or combining with gellan gel (embedded in the gel or spread on the gel surface). The effectiveness of the different formulations on the removal of potato and wheat starch was evaluated by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and colorimetric measurements. Enzymes dispersed in gel showed weak diffusion at the surface, resulting in poor starch breakdown and removal. On the contrary, amylase applied by pipette and spread on gel resulted in high starch removal selectivity and efficiency, with neither swelling nor damage to the fibres. These results validate protocols for the assessment of the enzymatic activity on glue-consolidated fibres, identify best application methods and confirm the excellent properties of amylase dispersions for the conservation of historic and archaeological textiles.Key points• Application of α-amylase by pipette and combined with gellan gel to remove starch glues from wool.• Systematic assessment of the best application methods following a multi-analytical protocol.• Enzymes dispersed in gel exhibit poor diffusion at the surface, leading to weak starch removal.• Enzymes applied by pipette and spread on gel are efficient in starch cleaning, without damage to the fibres.
基于淀粉的胶水广泛用于加固历史和考古纺织品中的易碎纤维。老化的织物受到水解/氧化和这些胶水的交联的影响，导致胶水的溶解度降低、形成裂缝和变色。酶对基于淀粉的胶水的水解作用很有前景，因为分子识别具有很大的选择性。然而，尚未探索系统评估应用酶制剂的最佳方法。在这里，α-淀粉酶通过吸取溶液或与结冷胶结合（嵌入凝胶中或涂在凝胶表面上）来应用。通过傅里叶变换红外（FTIR）光谱、扫描电子显微镜（SEM）和比色测量评估不同配方对去除马铃薯和小麦淀粉的效果。分散在凝胶中的酶在表面上显示出较弱的扩散，导致淀粉分解和去除效果不佳。相反，通过吸取溶液并涂在凝胶上应用的淀粉酶导致高淀粉去除选择性和效率，纤维既不会膨胀也不会损坏。这些结果验证了用于评估胶结纤维上酶活性的评估协议，确定了最佳应用方法，并证实了淀粉酶分散体在保护历史和考古纺织品方面的卓越性能。
关键点
• 通过吸取溶液和与结冷胶结合的方式将α-淀粉酶应用于从羊毛上去除淀粉胶水。
• 采用多分析协议系统评估最佳应用方法。
• 分散在凝胶中的酶在表面上扩散不良，导致淀粉去除效果不佳。
• 通过吸取溶液并涂在凝胶上应用的酶在清洁淀粉方面效率高，且不会损坏纤维。
