Polygalacturonases are enzymes that degrade pectic substances by breaking the glycosidic
bonds along the carbon chain of these molecules. These enzymes have various biotechnological
applications in the food industry, such as the extraction and clarification of fruit juices and
wines, the extraction of essential oils, the preliminary treatment of grape juice for the wine
industry, and fruit ripening, among others. The aim of this study was to produce and
characterize bacterial polygalacturonases isolated from Amazonian fruits with a view to their
application in the extraction of carotenoids. Initially, the production of polygalacturonase was
analyzed in cultures containing pure cultures of previously selected bacteria. The BCLB-640
and BCLB-197A strains showed enzyme activity of 5.52 and 5.13 U/mL. With these results, a
mixed culture was developed, and the highest production of polygalacturonase was observed
with the BCLB-197A + BCLB-640 mixed culture (14.68 U/mL). The enzymes produced in
pure and mixed cultures were characterized in terms of pH, temperature and metal ions. The
optimum reaction temperature and pH for quantifying enzyme activity were 50 °C and pH 5.0
for the three cultivation systems analyzed. Stability in relation to pH showed that the enzymes
from the BCLB-640 and BCLB-197A strains maintained pH 5.0 and for the mixed strain,
BCLB-197A + BCLB-640, the ideal pH was 4.5. The presence of metal ions had no positive
effects when compared to the control samples. The analysis of carotenoid extraction using
tomatoes showed that the enzymes have potential for application in both pure and mixed
cultures. The results of this work demonstrate the potential for applying pure and mixed cultures
of bacteria from Amazonian fruits to obtain polygalacturonases, as well as the application of
these enzymes in the extraction of carotenoids.
|
