K. Sawada and Mitsuo Ueda (2001) studied
enzyme processing and dyeing of textile
in reverse micellar solution. They examined the bioscouring of cotton with pectinase
(pH 4) (Aspergillus niger EC 3.2.1.15) and the modification of wool with
protease Bioprase APL-30 (Bacillus subtilis) (pH 7) in the reverse micellar system. At the
same time, dyeings of cotton
fabrics, polyester fabrics and
cotton/polyester fabrics (one-bath
dyeing) were carried out with direct dyestuffs, dispers dyestuffs,
reactive/dispers dyestuffs, respectively.
It is well
known that some kinds of surfactants form reverse micelle in non-polar
solvent. The reverse micellar system has excellent properties to solubilize
relatively large amounts of water at the interior of reverse micelle and to
provide stable aqueous microenvironment, so-called water-pool in the
non-aqueous media. Hydrophilic substances such as enzymes and dyes can also
be solubilized in the water-pool. If pectinase and other enzymes that are
suitably designed for textile processing display their activities in such
reverse micellar solution, it can be expected that this enzyme system may
have high potential for replacement of conventional practical textile
processes.
Surfactant
used in this study was sodium bis-2-ethylhexylsulpho-succinate (Aerosol-OT,
AOT). In these experiments, the liquors were prepared by an injection of
aqueous dye solution and of aqueous stock solution either in buffer alone
or enzyme in buffer to 0.05 M AOT/isooctane solutions.
The important
parameters were determined, for example weight loss, reduction of wax and
residual pectic substance (Methylene Blue Value) for cotton fabrics, tear
strength, weight loss, shrinkage percentage for wool fabric with prolonged
treatment compared with conventional systems.
As their
results, total effectiveness of the bioscouring of cotton with pectinase
enzyme could be remarkably improved by the use of the reverse micellar
system. Besides total effectiveness of protease for the modification of
wool in reverse micellar system is not necessarily excellent compared to
those in aqueous system.
As the dyeing
results, the construction of continuous one-step process of textile
processing and dyeing process is the ultimate subject for the textile
industry, reverse micellar system would be one of the most expected
candidate system for that purpose.