PRODUCTION AND CHARACTERIZATION OF PIGMENTS FROM BACTERIAL ISOLATES

Abstract

newlineABSTRACT newlinePigment producing microbes were isolated from Chandra river (H.P.) and medicinal plant newlineJusticia adhatoda. In the present study, three bacterial isolates were selected on the basis of the newlinecolor of the colony. Orange colored colony was observed from the water sample of Chandra river newlineand was named as ChP1, while yellow (Endo 2) and reddish (Endo 9) colonies were endophytes newlineisolated from Justicia adhatoda. Isolates were purified by successive streaking on NB agar newlinemedia. It was interesting to note that optimum temperature was 30°C and pH 7 for all the three newlinebacterial isolates. Out of the three isolates, Endo 2 showed change in color of the pigment at newlinedifferent pH. Yellowish colored pigment produced at pH 7.0, changed to greenish at pH 5 and pH newline9. Intracellular microbial pigments were extracted using acetone: methanol solvents (3:1) and newlinefurther characterized by bio-physical techniques and for antimicrobial activity. All the three newlineisolates showed fluorescence when analyzed under UV-transilluminator under 365 nm. Microbial newlinepigments were analyzed at wavelength range 200-800nm, two spectral peaks were observed in newlineall the three bacterial isolates. In case of ChP1, maximum absorption was observed at pH 7. In newlinecase of Endo 2, maximum absorption was observed at pH 5. In case of Endo 9, maximum newlineabsorption was observed at pH 7 and 9. From the HPLC analysis, it was observed that pigment newlinefrom ChP1 isolate showed 3 major and 2 minor peaks. Pigments from Endo 2 and Endo 9 isolate newlineshowed 2 major and 3 minor peaks. From the FT-IR analysis, it was observed that -OH, alkene, newlinemethylene and alkyl halide groups are present in the crude pigments. Pigment extracts were newlinetested for antimicrobial activity against Staphylococcus aureus, Escherichia coli and Candida newlinealbicans. Pigment extracted from all the three bacterial isolates showed antimicrobial activity newlineagainst Staphylococcus aureus. On the other hand, pigments from ChP1 and Endo 2 isolates newlinewere bactericidal, while pigment from Endo 9 showed bacteriostatic activity against newlineStaphylococcus aureus. Out of the three isolates only pigment from ChP1 isolate showed newlineantimicrobial activity with the variation of the pH. Crude pigments did not show any activity newlineagainst Escherichia coli and Candida albicans.