Influence of different parameters in the production of natural colorants by Talaromyces amestolkiae in batch fermentation

There is a worldwide interest in the development of processes for producing colorants from natural sources. Microorganisms provide an alternative source of these biocompounds using cultivation technology. The aim of the present work was to study the production of natural colorants by Talaromyces amestolkiae in 3 L bioreactor. Preliminary experiments were carried out using different agitation (100 to 600 rpm) at aeration rate of 2.0 vvm and 30°C. The experiments were performed during 240 hours and aliquots were taken each 24 hours to analyze the production of yellow, orange and red colorants (spectrophotometric analysis at 400. 470 and 490 nm, respectively), the pH and the sucrose consumption. At 100 and 150 rpm the fermented media (FM) did not remain homogeneous probably due to non-Newtonian behaviour of FM. However, with higher agitation the FM was homogeneous and it was possible to determine the colorants production. The higher colorants production was achieved at 500 rpm while the better results among the relation yellow and red colorants at 300 rpm. So, new experiments were performed using both agitation and the same conditions described before but increasing the pH to 8.0 after 96 hours of bioprocess. As result at 500 rpm an increase in the colorants production of 87% for yellow colorants and 250% to orange and red colorants were achieved. These results demonstrate the potential use of bioreactors for scale up the colorants production and implemented a strategy aiming to use bioreactors by filamentous fungi, which is sometimes difficult because culture broth rheology.