Surface Modification of Cellulose Acetate with Cutinase and ...

Subchapter 2.5
differences between controls and treated samples were more evident for CTA (figure.
5).
Figure 5. Epifluorescent photographs of cross-sections from (A) control and (B) treated
sample of CTA, competitively stained with Remazol Reactive Blue R, C.I. 61200. The
samples (2% w/v) were previously treated with 25 U mL -1 of cutinase, at pH 8 and
30º C, for 24 hours. The controls were subjected to the same conditions except for the
enzyme. Both images were acquired under the same conditions with a total
magnification of 1000x.
The hydroxyl groups appeared to be located mainly on the fibre surface where the dye
was chemically fixed, which could be attributed to a superficial action of cutinase.
Therefore, cross sections of fibres treated with cutinase conjugated with FITC were also
observed by Fluorescence microscopy (figure. 6).
Figure 6. Epifluorescent photographs of cross-sections from (A) CDA and (B) CTA
samples. The samples (2% w/v) were treated with 10 mg g -1 of FITC-conjugated
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