Characterization of a blue pigment isolated from an Antarctic Rhodococcus bacterial strain

Antarctic microorganisms adopted adaptive strategies that include the production of dif-ferent compounds like biofilm, pigments, or antibiotics (1). For what concerns pig-ment’s production, these are produced by particular processes like photo/chemo-synthesis, or as protection from solar light radiation (in particular UV light), a property that is particularly important in the Antarctic ecosystem due do the stratospheric ozone hole (1). Most of pigments that are pro-duced are carotenoids, melanin, violacein, prodigiosin, pyocyanin, actinorhodin, and zeaxanthin. This preliminary study focuses on the char-acterization of a novel pigment produced by the Antarctic bacterium Rhodococcus ef1 that shows important peculiarities. It was characterized among UV-Vis spectroscopy, HPLC analyses and Mass spectroscopy. Fur-thermore, some properties have been moni-tored, as pH behavior, solubility, and its thermal and photo stability. This new pig-ment displays different colour according to media conditions, i.e. it is blue in alkaline medium, while it is pink in acidic medium. The extraction in water is favoured by high temperatures (around 55°C) and, after ex-traction, it remains stable at room tempera-ture for several days. This pigment, due to its peculiar features, might find interesting applications in various field, in particular in medical or energy fields, as anticancer or as electron shuttle in microbial fuel cells.