Material Science and Engineering

Biography

Biography: Radames JB Cordero

Abstract

Melanins are pigments found in most, if not all, life forms. In biology, melanins are related to function in photoprotection, camouflage, antioxidant, metal chelators, drug resistance, and virulence. These insoluble and amorphous substances are also attractive because of their unique physicochemical properties, including a broad-band UV-Visible optical absorption and the ability to conduct/store electrical charge depending on the water content. Studies from our laboratory demonstrated that melanized fungi can harness chemical energy by capturing high-energy electromagnetic radiation and act as a thermal insulator, protecting cells against heat and cold stress. This research project began evaluating the role of melanin on thermoregulation in the fungus Cryptococcus neoformans; an ideal model since it can generate different pigments depending on exogenous precursor (ie. L-Dopa, dopamine, epinephrine). We initiate our studies by monitoring the apparent temperature differences of L-Dopa pigmented versus non-pigmented C. neoformans communities using infrared imaging. Our data shows that melanized fungal material exhibit slower dissipation of heat when switch from a hot to a cold environment and different apparent temperatures following irradiation with microwave or infrared frequencies, even in the absence of water. These results suggest that melanin alters the heat absorbtion/release of fungal material, and, consistent with the theory of thermal melanism in ectotherms, melanization can provide a mechanism by which microorganisms can regulate their absolute temperatures in response to thermal and/or radiation changes in their environment.