Isolation of pigment producing Bacteria and characterization of extracted pigment

Introduction: Many artificial synthetic colorants, which have widely been used in food industries, cosmetic and pharmaceutical manufacturing processes, comprise various hazardous effects. Therefore the utilization of pigments from natural sources has been increased in recent years to counter the harmful effects of synthetic pigments and their industrial byproducts on humans and the environment. Among natural pigments, pigments from microbial sources are potentially good alternative ones. Materials and methods: In the present study the pigment producing bacteria was isolated from a lake in Qom by water sampling method. Using the universal PCR method, the 16S rDNA gene was amplified and then sequenced to study bacterial phylogeny and taxonomy. To improve the pigment production different growth conditions were examined. Subsequently, the pigment was extracted by different solvents (methanol, ethanol, isopropanol, hexane, chloroform and acetone) with differentconcentrations. The appropriate solvent for the extraction was chosen and then the extracted pigment subjected to TLC and HPLC for purification. The extract was further characterized by NMR. Results: Based on the morphological, biochemical characterization and 16S rDNA gene sequencing analysis, the orange pigment producing bacteria was identified as a member of Kocuria genus. The optimum condition for its pigment production was obtained in LB (using sea water) at 26 °C and pH 7-8 under 160 rpm shaking speed for 6 days. Among different examined solvents, methanol and isopropanol were selected to extract the pigment for purification by TLC and HPLC. The purified extract was analyzed by NMR and classified as a carotenoids derivative. Conclusion: Pigment producing microorganisms hold a promising potential to meet present day challenges. The results of our study showed that the isolated bacteria produced a considerable amount of carotenoid. Amongvarious pigments, carotenoids have attracted great attention due to the beneficial role on human health and their markets have been forecast to reach $1.2 billion by 2018.

کلیدواژه ها:

Pigments ، Carotenoids ، Kocuria ، Thin layer chromatography