Antibacterial dyeing of silk with prodigiosins suspention produced by liquid fermentation

As a kind of natural dye, microbial pigments are attracting more and more attention for their application in textile dyeing. In this study, prodigiosins suspension produced by fermentation of Serratia marcescens was utilized as a novel kind of cleaner dye liquor for silk fabric dyeing. The average particle size of pigment particles was 217.1 nm and the prodigiosins concentration was determined to be 69.38 mg/L. Effects of technical parameters including dyeing temperature, dyeing time and dye liquor pH on dyeing effect and antibacterial capability of dyed fabrics were explored. The results indicated that when the dyeing temperature was 80 °C with a holding time of 30 min, dyed silk under dye bath pH 2.1 possessed high color strength, good color fastness and outstanding bacteriostatic rate of above 93.0% against Staphylococcus aureus. In addition, in vitro cytocompatibility test indicated that dyed silk fabric had no potential cytotoxicity to L929 cells. This study provided an innovative clean approach of dyeing silk with prodigiosins and endowed the fabric with antibacterial activity, simultaneously.