Page 143 - Advances in Textile Biotechnology

124 Advances in textile biotechnology

pharmaceutical industry, controlled release and the biopolymer fi elds, all

these areas can also profit from a surface bio-regeneration of cellulose
reactivity (Glasser, 2004).
The affinity of cutinase for cellulose acetates can be improved by adding

CBMs, resembling natural carbohydrate esterases. However, because the
washing procedure after the enzymatic treatments was mild, in terms of pH
and temperature, it would be important to include in future works controls
like null mutated or inhibited cutinases for a better assessment of the inter-

ference in the fibre properties of adsorbed protein.

In order to transform the reported biomodifications into cost competitive
industrial processes, a considerable amount of work is needed. A better
biochemical characterization of cutinase fusion proteins is required to
understand their interaction with the cellulose acetates. The optimization
of the expression system is also needed for higher yields of protein produc-
tion, essential from an economics point of view.
The properties of modified cellulose acetates have to be characterized in

detail before any feasibility study is carried out into the upgrading of the
optimized processes to an industrial scale and the application of such
modifi ed fibres for the production of textile products having speciality

properties.

5.6 Future trends
The textile industry shows successful examples of enzyme applications in

the processing of natural fibres. For cotton, enzymes are used in almost all
stages of its wet processing, almost completely replacing conventional
textile practices such as stone washing of denim. However, for man-made

fibres, in particular the synthetic fibres, the scenario is very different. Nature
did not design efficient ways to use and integrate these fibres as part of

ecosystems and, therefore, they are not natural substrates for enzymes.
Moreover, because of their chemical structure, man-made fi bres require

high amounts of energy and chemicals for their modification in order to
achieve the desired properties. Taking into account that they have a market
share of more than 60% (Engelhardt, 2008), it is imperative to address the
environmental and safety issues brought by their processing and disposal.
Finding eco-sustainable alternatives to traditional practices for man-

made fibres in an extremely competitive market, such as the textile industry,
is a hard challenge. It is essential to fi nd, develop and improve methodolo-

gies for the enzymatic treatment of a given fibre (based on the target
chemical bonds of the polymer molecules). Nature’s biodiversity provides
us with a large collection of enzymes well suited for supporting life, however,
they may not always be well suited for our technological interests (Arnold,

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