초록
<P><B>Background</B></P><P>Removal of non-cellulosic impurities from cotton fabric, known as scouring, by conventional alkaline treatment causes environmental problems and reduces physical strength of fabrics. In this study, an endo-polygalacturonase (EndoPG) from <I>Aspergillus aculeatus</I> produced in <I>Pichia pastoris</I> was evaluated for its efficiency as a bioscouring agent while most current bioscouring process has been performed using crude pectinase preparation.</P><P><B>Results</B></P><P>The recombinant EndoPG exhibited a specific activity of 1892.08 U/mg on citrus pectin under the optimal condition at 50 °C, pH 5.0 with a V<SUB><I>max</I></SUB> and K<SUB><I>m</I></SUB> of 65,451.35 μmol/min/mL and 15.14 mg/mL, respectively. A maximal activity of 2408.70 ± 26.50 U/mL in the culture supernatant was obtained by high cell density batch fermentation, equivalent to a 4.8 times greater yield than that from shake-flask culture. The recombinant enzyme was shown to be suitable for application as a bioscouring agent, in which the wettability of cotton fabric was increased by treatment with enzyme at 300 U/mL scouring solution at 40 °C, pH 5.0 for 1 h. The bio-scoured fabric has comparable wettability to that obtained by conventional chemical scouring, but has higher tensile strength.</P><P><B>Conclusion</B></P><P>The work has demonstrated for the first time functions of <I>A. aculeatus</I> EndoPG on bioscouring in eco-textile processing. EndoPG alone was shown to possess effective scouring activity. High expression level and homogeneity could be achieved in bench-scale bioreactor.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s12896-017-0334-9) contains supplementary material, which is available to authorized users.</P>