Present study has focused on the effect of chemical (solvents) and physical (photo) conditions on pigment production and its bioactivity of intracellular orange fluorescent pigment (IOFP) extracted from soil bacterium Bacillus endophyticus. Standardization of pigment and its colour stability was confirmed by using different solvents (70% & 100% ethanol, hexane, heptane, ethyl acetate, acetone, petroleum ether, chloroform, methanol and distilled water), photo conditions (Dark, U.V light and White light) on pigment production and its bio-activeness by antibacterial activity using agar cup plate method against gram-positive (Staphylococcus aureus, streptococcus pyogenes and Listeria monocytogenes) and gram-negative (Salmonella typhi, Vibrio cholera, Shigella Flexneri and E.coli) human pathogens and purification of pigment by TLC coupled with bio-autographic studies. Acetone is proved to be the best solvent for extraction and the pigment was stable in all solvents without changing its colour except heptane. When compared to control (dark incubation) antibacterial activity of IOFP produced in U.V and W. Light was effective against all tested pathogens with slight differences in their antibacterial activity. TLC bio-autographic studies reveal that the separated pure band shows clear zone of inhibition under red back ground of live cells stating that, the compound is active against human bacterial pathogens. Hence this study concludes that, the production and biological activity of the IOFP was independent of light incubation, and TLC guided bio-autographic approach offers a rapid detection technique that avoids the testing of purified fraction once again.
Optimization of Monascus Pigment Production and its Antibacterial Activity