Stability and dyeing performance of Micrococcus luteus pigment on cotton and polyester fabrics

The increasing demand for eco-friendly dyes has led to the exploration of bio-pigments derived from natural sources such as microbes. Thus, this study investigated the stability of pigment extracted from Micrococcus luteus against various environmental stresses and its application in cotton and polyester fabrics dyeing. Stability tests were conducted by measuring the absorbance of the extracted pigment at different pH levels, temperatures and concentrations of oxidizing and reducing agents. The pigment was then used to dye fabric samples via the immersion dyeing method. The exhaustion and fixation of the pigment to the fabric samples were evaluated using absorbance method. Visual observations and photographic comparisons against un-dyed similar fabrics were employed to evaluate color fastness after washing with detergent and exposure to sunlight. H2O2 and temperature were identified as significant predictors of pigment stability with p value of 0.0013 and 0.02, respectively. Dyeing with the pigment resulted in vibrant shade of uniform colors on both fabrics. The pigment exhaustion for cotton fabric was found to be 75%, while that of Tetron 6000 fabric was 65% with significant statistical difference in pigment uptake ( $$\:p=0.002$$ ). The pigment showed moderate stability and dyeing performance, making the Micrococcus luteus pigment a possible alternative for further scale-up investigation for commercial applications in eco-friendly textile dyeing.