A kinetic model for prodigiosin production by Serratia marcescens as a bio-colorant in bioreactor

Microbial pigments have promising applications in many industries such as pharmaceutical cosmetics and food processing. Among these pigments, prodigiosin, the red pigment that produced by Serratia marcescens, represent one of the valuable pigment due to a large industrial and medical benefits. In this study, growth kinetic of S. marcescens in a 7L bioreactor in an optimized medium was investigated. The result showed that the maximum cell mass and prodigiosin were 14.4 mg/mL and 594.88 mg /L respectively. The batch fermentation kinetics was studied via developing a simple model based on the Luedeking–Piret correlation for prodigiosin yield, Logistic correlation for biomass formation and Luedeking–Piret-like correlation for substrate consumption with correlation coefficient of 0.996, 0.9989 and 0.9964 respectively. The partially purified prodigiosin was tested for its ability to dyeing different types of textiles The Methanolic extract of prodigiosin was able to color wool, cotton, silk, nylon and polyester with the same degree of acquiring color. The result showed that the color of all types of pigmented textiles were stable in the acidic (pH 3) and neutral pH and reduced in the alkaline solution at the basic pH greater than 13. In addition, the pigment textiles maintained their color when exposure to bleaching upon treated with detergents and high temperature (100°C) whereas, they were sensitive when exposure to light. our finding confirms previous findings and contributes additional evidence on using prodigiosin as a promising ecofriendly bio colorant of textiles.