Identification Of A Golden Yellow Biocolorant From Microbacterium Pumilum NITD
Natural colorants like microbial pigment are gaining worldwide attention due to their strong colour and
nutraceutical properties. The current study focuses on the extraction of pigment produced by a newly identified bacterium
followed by characterization of the pigment by TLC and HPLC. The isolate was identified as Microbacterium pumilum.
Growth pattern of the bacterium was studied in BHI medium at 30°C, initial pH 7.2 and 120 rpm. UV-Vis
Spectrophotometry of the extracted pigment (in methanol) showed three distinct peaks at 428, 450 and 476nm which is an
inevitably characteristic of a carotenoid i.e. zeaxanthin. Different solvent system was used to screen the favorable running
phase for TLC with suitable resolution of the pigment. Both TLC and HPLC analysis showed the extracted pigment similar
with standard zeaxanthin. Bacteria often produce a cocktail of polar and nonpolar carotenoids limiting their industrial
applications. This study revealed that M. pumilum NITD produces zeaxanthin as a major carotenoid in its stationary phase
and could be used as a potent zeaxanthin producer for future applications.
Index Terms— Carotenoids, Zeaxanthin, Microbacterium pumilum, HPLC