Surface Modification of Cellulose Acetate with Cutinase and ...

Chapter 4
other approache describes the fusion of subtilisin E with a high molecular weight
elastin-like polymer (Subchapter 3.3- Araújo et al, 2008b). The chimeric enzyme
presented a molecular weight above 116 KDa. Wool yarns treated with the chimeric
enzyme and subjected to several machine washings, presented a significantly lower
damage than wool treated with the native enzyme, in the same conditions. Moreover
yarns treated with chimeric high molecular weight subtilisin presented a tensile
strength resistance comparable to the original one while yarns treated with
commercial enzyme kept less than half of its initial resistance.
The results presented in this thesis prove that molecular biotechnology provides the
approaches that make possible the genetic modification and production of enzymes
either by site-directed mutagenesis or by fusion with functional domains or proteinbased
polymers, wich can represent promising alternatives for fibres bio-finishing
processes at an industrial level. Here we developed effective ways of hydrolysing
both synthetic and natural fibres surface and created environmentally friendly
options to the conventional chemical treatments.
Nevertheless, the power of molecular genetics approaches linked to biotechnology
has not yet been fully exploited and the processes developed here need to be further
characterized for its complete understanding and optimization.
Further studies will contribute to a better understanding of the interaction of these
enzymes with the substrates concerning factors such as sorption, movement on the
fibre surface and the role of binding modules. It is also our intention to design new
genetically modified enzymes and upgrading the enzymatic surface modification
technology from laboratory to a large-scale process, contributing for new ecological
industrial processes.
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