Piocianina como biocorante de material têxtil

Abstract

Bioprospecting of microbes allows the use of their metabolites, such as biodegradable molecules in substitution of not eco-friendly compounds, for example of pigments as good natural substitutes for synthetic dyes. This work aimed to produce, to extract and to characterize pyocyanin from two wild isolates of Pseudomonas aeruginosa, TGC02 and TGC04, and to apply the pigment as dyeing agent in two fibers. King A broth added with 2% (w/v) of malt bagasse were used to produce about 30 ml of pyocyanin (585 μg/ml) with a high degree of purity. Kinetic parameters of maximum cell production, maximum pigment production and yield coefficient were determined. In addition, cell concentration and growth rate were determined. The dyeing of 50 and 100 μg/mL of pyocyanin in cotton and polyester/elastane fibers was done using the exhaustion method, using sodium bicarbonate as mordant. Both isolates were similar in terms of microbial parameters. The cell population was increased up to 9.5 times from the inoculum, producing a maximum concentration of pyocyanin about 1.0 μg/mL.h-1, and increased significantly after 36 h and seemed to modulate the microbial growth. The yield coefficient was up to 240 μg/mL.UA-1. Pyocyanin was more functional to the cotton fiber and produced two shades of blue, without undergoing significant changes after washing and drying. Additionally, the highest percentages of pigment absorption and the lowest percentages of exhaustion were recorded. The opposite was found in the polyester/elastane fiber. The adsorption of the pigment was low, influencing the color resulted, whose perception in white light was a very pale lilac-bluish color. Additionally, the shades poorly varied as a function of the concentration of pyocyanin applied. In conclusion, pyocyanin may be used as alternative biocolorant on cotton fibers.