Surface Modification of Cellulose Acetate with Cutinase and ...

Surface Modification of Cellulose Acetate with Cutinase and Cutinase Fused to Carbohydrate-binding Modules
which the buffer substituted the enzyme. After enzymatic treatment, all fabric samples
were washed according to the procedure described earlier (see 2.3).
3. Results and discussion
3.1. Effect of cutinase concentration on the modification of cellulose di- and triacetate
The media conditions, such as buffer, pH and temperature, were chosen based on earlier
studies performed in our laboratory (Matamá et al., 2006), using the esterase activity
determination methodology described earlier. The conditions chosen were phosphate
buffer pH 8 and the lowest optimum temperature 30º C. The hydrolysis of the acetate
groups in cellulose ester substrates leads to the formation of hydroxyl groups at the
fibres surface and to the release of acetic acid to the treatment solution. The effect of
cutinase concentration was analysed by measuring the acetic acid in the treatment
solutions, after an incubation period of 8 hours (figure. 2).
Figure 2. Effect of cutinase concentration on the acetic acid release. The CDA and
CTA fabrics (2% w/v) were treated during 8 hours, at pH 8 and 30º C, with several
concentrations of cutinase expressed as esterase activity in U mL -1 (see 2.2).
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