Abstract
Cellulases are a complex of enzymes necessary for the complete solubilization of cellulose in sugars, thus playing a key role in the natural carbon cycle through the hydrolysis of lignocellulosic structures. The aim of this study was to evaluate the increase in the capacity of Talaromyces amestolkiae CMIAT 055 to produce cellulases by optimizing the components of the culture medium containing banana pseudostem as an inducer, as well as in different agitation configurations in a bioreactor. Optimization was performed through statistical experimental design (Plackett-Burman and DCCR), a study of pH control in bioreactors, and a study of the agitation system by comparing impellers with different flow profiles in the liquid medium. For this purpose, a wild strain of Talaromyces amestolkiae CMIAT 055 was used. In the Plackett-Burman and DCCR statistical design, four components of the culture medium were significant and optimized for greater synthesis of FPase: banana pseudostem, CaCl2, KH2PO4, and urea. In bioreactors tests, these parameters were beneficial for greater enzyme activities: maintenance of pH at 5.0, use of Pitched blade impeller, and rotation speed at 300 rpm. Comparing the first test using banana pseudostem in an Erlenmeyer flask to the last fermentation process in bioreactors, it was observed that the total cellulase activity increased from 424.7 FPU/L to 2172.8 FPU/L. This fact showed that the strategies adopted in this study are a pertinent way to reduce the cost of enzyme production through the use of lignocellulosic materials.
Sugarcane bagasse as feedstock for cellulase production by Trichoderma harzianum in optimized culture medium