Development of dye-sensitized solar cells using pigment extracts produced by Talaromyces atroroseus GH2.

The identification of more efficient, clean, secure, and competitive energy supply is necessary to align with the needs of sustainable devices. For this reason, a study for developing innovative dye-sensitized solar cells (DSSCs) based on microbial pigments is reported starting from Talaromyces atroroseus GH2. The fungus was cultivated by fermentation and the extracellular pigment extract was characterized by HPLC-DAD-ESI-MS analyses. The most abundant compound among the 22 azaphilone-type pigments identified was represented by PP-O. The device's behavior was investigated in relation to electrolyte and pH for verifying the stability on time and the photovoltaic performance. Devices obtained were characterized by UV-vis measurements to verify the absorbance intensity and transmittance percentage. Moreover, photovoltaic parameters through photo-electrochemical measurements (I-V curves) and impedance characteristics by Electrochemical Impedance Spectroscopy (EIS) were determined. The best microbial device showed a short-circuit current density (Jsc) of 0.69 mA/cm2, an open-circuit photo-voltage (Voc) of 0.27 V and a Fill Factor (FF) of 0.60. Furthermore, the power conversion efficiency (PCE) of the device was 0.11%. Thus, the present study demonstrated the potential of microbial origin pigments for developing DSSCs.

Biotechnological approaches for the production of natural colorants by Talaromyces/Penicillium: A review.

There has been an increased interest in replacing synthetic colorants by colorants obtained from natural sources, especially microbial pigments. Monascus pigments have been used as natural colorings and food additives in Asia for centuries but have raised toxicity issues. Recently, Talaromyces/Penicillium species have been recognized as potential strains to produce natural pigments similar to those produced by Monascus species. To date, it has not been published a literature compilation about the research and development activity of Talaromyces/Penicillium pigments. Developing a new bioprocess requires several steps, from an initial concept to a practical and feasible application. Industrial applications of fungal pigments will depend on: (i) characterization of the molecules to assure a safe consumption, (ii) stability of the pigments to the processing conditions required by the products where they will be incorporated, (iii) optimizing process conditions to achieve high yields, iv) implementing an efficient product recovery and (v) scale-up of the bioprocess. The above aspects have been reviewed in detail to evaluate the feasibility of reaching a commercial scale of the pigments produced by Talaromyces/Penicillium. Finally, the biological activities of the pigments and their potential applications are discussed.