A Biologically Active Yellow Pigment From Micrococcus luteus (PX673990), Production, Extraction, Purification,...

Microbes are a potential source of bio-pigments, offering safe and cost-effective alternatives to synthetic dyes. This study demonstrates the utilization of orange peel waste as a cost-effective substrate for pigment production by Micrococcus luteus. The nucleotide sequence of M. luteus, with 99.9% similarity, was deposited in GenBank under the accession number PX673990. The microbial pigment was further partially purified, yielding 14.94 ± 0.09 µg/mL of crude pigment under optimized conditions and 2.4 mg/L at partially purified conditions. High-performance liquid chromatography (HPLC) analysis demonstrated two prominent, broad peaks at 2.060 and 2.423 min, suggesting the presence of an oxygenated carotenoid-like compound. Furthermore, Fourier transform infrared (FTIR) and combined ¹H and ¹³C nuclear magnetic resonance spectra have suggested that the pigment is similar to a glycosylated carotenoid-like compound with esterified fatty acids. The x-ray diffraction (XRD) patterns exhibit sharp peaks between 17° and 28°, indicating the high crystallinity of the purified pigment. Furthermore, the partially purified pigment can scavenge 42.44% ± 0.03% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 37.245% ± 0.05% of ABTS. This partially purified yellow pigment has been applied to various textiles and paper for dyeing. Different fastness properties, resistance to rubbing, washing, light, and temperature, were also evaluated. This study suggests that the bio-pigment obtained from the M. luteus strain PPIOR 1 (PX673990) exhibits effective dyeing properties. It also suggests that this pigment could be used as a sustainable, bio-based dye for the textile and paper industries in the near future. Further, its ability to produce at low cost and its various substrate affinities effectively substitute the synthetic dyes.