Estudo da produção de pigmento por linhagem endofítica de Talaromyces minioluteus / Penicillium minioluteum em diferentes temperaturas
Resumen
In view of the risks offered by synthetic pigments to humans and the environment, as well as
the growing global interest in healthier and more natural products, the study and interest in the
production and use of natural pigments has become increasingly attractive due to less harmful
to human health and nature. A promising alternative source for obtaining natural pigments are
microorganisms, among them are filamentous fungi, since they have a high productivity and
are capable of synthesizing compounds with a wide range of colors. In this context, the present
work aimed to evaluate the production of red pigment by the fungus Talaromyces
minioluteus/Penicillium minioluteum in submerged cultures under different temperatures.
Initially, a microbiological screening of fungal colonies was carried out using a plating
methodology, in order to isolate the endophytic strain of Talaromyces minioluteus/Penicillium
minioluteum. After obtaining and isolating the species in question, 8 different culture media
were analyzed in order to obtain the most favorable for the red pigment production. Submerged
cultures in shaken flasks conducted at 28 °C, 250 rpm for 120 hours, showed that the most
successful medium to obtain a high production of red pigment was SABORAUD medium
(medium 4) with a final pigment concentration of approximately 23.07 AU (Absorbance
Unities) for a wavelength of 500 nm. Submerged fermentations using the SABORAUD medium
were carried out in a rotating incubator at 250 rpm at temperatures of 20, 24, 28 and 32 °C.
Subsequently, cultures were carried out in 4 L benchtop bioreactors of useful capacity at 400
rpm and 0.5 vvm under the same temperature conditions in order to validate the results obtained
in a rotary incubator. As a result, the highest red pigment yields were observed at 24 °C, with
absorbance values at 500 nm (ABS500) and approximate red pigment concentration of 41.40
AU and 8.07 gpigment/L, respectively. Evaluated the effect of temperature on the red pigment
synthesis process, three extraction routines were performed, which routine 3 was used in
samples of 20, 24 and 28°C in order to obtain a ratio between absorbance (ABS500) and pigment
concentration (gpigment/L). Finally, using the Contois cell growth model, two kinetic modeling
of the process was proposed, Modeling A being characterized by assuming glucose as the only
limiting substrate and the pigment as a product not associated with growth, and Modeling B
characterized for presuming the production of pigment via a precursor from the consumption
of the nitrogen source. Both presented satisfactory results, however, Modeling B was the most
adequate to describe the behavior of the bioprocess. Thus, the results obtained in this work show
the potential of the endophytic fungus Talaromyces minioluteus / Penicillium minioluteum to
obtain the red pigment via cultures submerged at different temperatures.