Effect of coloring pH and mordant on fungal dyes quality using woolen yarn

Abstract

Fungal dyes are an important alternative dye. In the present study, woolen yarn was dyed with 10 fungal dyes derived from three isolates of Aspergillus, two isolates of Paecilomyces, three isolates of Penicillium, and two other fungal isolates (Monascus purpureus and Trichoderma harzianum) using two different mordants (alum and FeSO4.7H2O) by three different dyeing pH (3, 6, and 9). Aspergillus, Paecilomyces, Penicillium, and T. harzianum isolates were grown on mineral salts glucose medium, while M. purpureus isolate grown on rice. The color of filtrate and range of colors developed on dyed materials were measured by RHS color chart. The results indicated that the pH value of dye and mordant had a great effect on the color that appears. When the pH value was 3, it exhibited a strong color of woolen yarn than the pH value of 6 or 9. Mordant FeSO4.7H2O produced almost all darker colors than mordant alum on woolen yarn. The present study indicates that the selected fungal isolates can serve as novel sources of dyes for textile applications.