GUEDES, C. A. L.; http://lattes.cnpq.br/1652940079221996; GUEDES, Clotildes Alvino Leite.
Resumo:
The widespread use of cellulolytic and hemicellulolytic enzymes in some processes has
been limited by their high cost, therefore studies have been developed with the objective
of producing these enzymes through the solid state (SSF) and submerged (SmF)
fermentation process from lignocellulosic agroindustrial residues, thus reducing enzyme
production costs and adding value to the residue. Thus, the objective of this work was to
evaluate the enzymatic production of cellulolytic and hemicellulolytic enzymes by the
filamentous fungus Trichoderma reesei by solid and submerged fermentation using sisal
fiber as substrate. The characterization of sisal fiber was performed with the objective of
to know its composition. Solid state and submerged fermentation was performed using
the Trichoderma reesei microorganism at a concentration of 107 spores/g or mL at a
temperature of 28 °C. Cellulase (CMCase, FPase and β-glycosidase) and hemicellulase
(Endo-β-1,4-xylanase) enzymes were studied using experimental design 22 with 3
central points and kinetic monitoring of production for 240 h, analyzing the influence of
humidity and wheat bran content on enzyme production in solid fermentation, and the
ratio m/v and wheat bran content in submerged fermentation. The characterization
showed that this substrate has potential to be used in the production of cellulolytic and
hemicellulolytic enzymes, mainly because it presented a satisfactory percentage of
alfacellulose (58.40%) and hemicellulose (15.21%), which are inducers of these
enzymes and acid pH (4.35) ideal for the production of enzymes in solid and submerged
fermentation with fungi. The statistical treatment of the designs at a significance level of
95% showed that in the SSF the initial humidity and wheat bran contents influenced the
enzymatic activity of the enzymes CMCase, FPase, xylanase and β-glycosidase, and in
the FSm the variables of wheat bran and mass/volume ratio (m/v) of substrate
concentration also influenced the enzymatic activity of the enzymes of the enzymes
CMCase, xylanase and β-glycosidase. In the SSF, the assay carried out with 60%
humidity and 50% wheat bran in the substrate composition showed the highest
enzymatic activity for all studied enzymes. CMCase enzyme showed maximum activity
of 0.46 U/mL, FPase enzyme showed maximum activity of 0.07 U/mL, xylanase
enzyme showed maximum activity of 78.96 U/mL and β-glycosidase enzyme showed
maximum activity of 13.88 U/mL. In SmF, the assay with 5% of substrate concentration
and 50% of wheat bran presented the highest enzymatic activity for all enzymes studied.
The CMCase enzyme showed a maximum activity of 0.28 U/mL, the xylanase enzyme
presented a maximum activity of 78.34 U/mL and the enzyme β-glycosidase showed a
maximum activity of 9.47 U/mL. Given the fermentations used, SSF obtained the best
results when compared to SmF for the production of CMCase, xylanase and β-
glycosidase enzymes.