Desenvolvimento de culturas mistas para a produção de poligalacturonases bacterianas isoladas de frutos amazônicos

Abstract

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.