Screening and characterization of Chromobacterium piscinae AMA-5 for enhanced production of violacein and its ability of textile dyeing.

A violet pigment (violacein) bacterial isolate AMA-5 was isolated from soil samples collected from Achanakmar Biosphere Reserve, Mungeli district, Chhattisgarh, India. The yield of biocolor from this isolate was screened in minimal medium after 48 h of incubation at 37°C ± 2°C temperature. The violet pigment was extracted in ethanol. It was also observed that ammonium chloride (2.5 g/1000 mL) as a nitrogen source is the best to enhance AMA-5 pigment production among other nitrogen sources (ammonium sulfate, tryptophan, ammonium iron sulfate, and peptone). The Sanger sequencing of 16S rDNA of strain AMA-5 showed similarity with Chromobacterium piscinae. From the available literature and research articles, it was assumed that this violet color pigment is violacein. It was further verified by conducting high-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR), and proton nuclear magnetic resonance (¹H-NMR) analysis. The violet biocolor that extracted was used in cotton and polyester fabric dyeing. After the fabrics treated with sodium chloride as a mordant were completely dried, it was identified that the color was solidifying. Overall study showed that C. piscinae AMA-5 has good potential for production of violacein, which is the most important industrial natural dye used to add color to textile products.