Production of ß-glucosidase by Rhodotorula oryzicola and use of enzyme for hydrolysis of sugarcane bagasse delignified.

Bioethanol is obtained by hydrolysis of sugarcane bagasse by cellulases. Commercial cellulases are expensive and have a low concentration of ß-glucosidase (EC 3.2.1.21), which decrease hydrolysis efficiency. The present work aims to produce supernatant rich in ß-glucosidase (BGL) using the yeast Rhodotorula oryzicola and apply it in the hydrolysis of delignified sugarcane bagasse. Yeast fermented in a modified YPD (Yeast Peptone Dextrose) medium with 0.5% (w/v) cellobiose and 1.0% (w/v) glucose produced BGL with a specific activity of 1.44 ± 0.013 U/mg. Partial purification of BGL by acetone showed a specific activity of 3.48 U/mg. The optimum pH and temperature were 6.02 and 65 °C, respectively. BGL partially purified (BGLppR.oryzicola) by acetone showed tolerance to glucose, with a relative activity of 82.89 ± 0.11%. The activity increased with the addition of iron sulfate and zinc sulfate and decreased with manganese sulfate. BGL partially purified was thermal stable, with a relative activity of 85.59% after 60 min at 90 °C. BGL partially purified applied in the hydrolysis of sugarcane bagasse delignified with 3% (w/w) NaOH + 6% (w/w) Na2SO3 showed a conversion rate of 72.46 ± 1.60%. The results showed that BGL partially purified is a glucose tolerant cellulase of low-cost, promising the application of bioethanol production.

Development of membranes based on carboxymethyl cellulose/acetylated arrowroot starch containing bromelain extract carried on nanoparticles and liposomes.

Polymeric membranes have been used in several applications, including their use as curatives in cutaneous wounds. Bromelain has long been used for anti-inflammatory purposes, so the objective of this work was to produce carboxymethylcellulose-acetylated blends, incorporate bromelain, characterize the systems, compare the blends with bromelain loaded in nanoparticles and liposomes and, finally, to evaluate their healing potential. Four membrane formulations were produced by solvent evaporation: the control, membranes containing free bromelain, bromelain-loaded nanoparticles (NPs) and bromelain-loaded liposomes (LIPs). The enzyme concentration was the same for all formulations. Transparent, flexible and intact films were obtained. The membranes containing free bromelain, bromelain-loaded NPs and bromelain-loaded LIPs had higher water content, lower water vapor permeability and maximum tensile strength, and greater elongation at rupture. The capacity to absorb simulated exudate was higher in samples containing free bromelain, and bioadhesion was reduced in the presence of free bromelain compared to the control. An in vivo assay was performed to verify the membranes' healing potential. Histological analysis revealed no edema on the 14th day in animals treated with membranes containing bromelain-loaded NPs and LIPs.

Evaluation of guava during different phases of the industrial processing.

In this work we studied the contents of pectin and protein, pectinmethylesterase (PME) activity, and PME stability in various stages of industrial processing, due to the implication of these values on the quality of the final product. The results of the PME stability at different values of pH showed residual PME activity at alkaline pH (7.0, 8.0, 8.5 and 9.5) and high stability at pH 4.0. These results show that pH treatment is not an efficient method to inactivate the PME enzyme. The presence of residual PME activity in all steps of industrial processing was also verified, showing that PME can change the quality of the pulp during storage.